Publisher: Cambridge University Press   (Total: 387 journals)

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Showing 201 - 387 of 387 Journals sorted alphabetically
J. of British Studies     Full-text available via subscription   (Followers: 34, SJR: 0.246, CiteScore: 0)
J. of Child Language     Hybrid Journal   (Followers: 30, SJR: 1.035, CiteScore: 2)
J. of Chinese History / 中國歷史學刊     Hybrid Journal  
J. of Classics Teaching     Open Access  
J. of Clinical and Translational Science     Open Access  
J. of Dairy Research     Full-text available via subscription   (Followers: 8, SJR: 0.573, CiteScore: 1)
J. of Demographic Economics     Hybrid Journal   (Followers: 3, SJR: 1.227, CiteScore: 1)
J. of Developmental Origins of Health and Disease     Hybrid Journal   (Followers: 2, SJR: 0.843, CiteScore: 2)
J. of Diagnostic Radiography and Imaging     Hybrid Journal   (Followers: 4)
J. of East Asian Studies     Full-text available via subscription   (Followers: 17, SJR: 0.59, CiteScore: 1)
J. of Ecclesiastical History     Hybrid Journal   (Followers: 19, SJR: 0.138, CiteScore: 0)
J. of Economic History     Full-text available via subscription   (Followers: 47, SJR: 1.82, CiteScore: 2)
J. of Experimental Political Science     Full-text available via subscription   (Followers: 7, SJR: 2.526, CiteScore: 2)
J. of Financial and Quantitative Analysis     Full-text available via subscription   (Followers: 50, SJR: 3.636, CiteScore: 2)
J. of Fluid Mechanics     Hybrid Journal   (Followers: 193, SJR: 1.591, CiteScore: 3)
J. of French Language Studies     Hybrid Journal   (Followers: 7, SJR: 0.163, CiteScore: 0)
J. of Functional Programming     Hybrid Journal   (Followers: 1, SJR: 0.458, CiteScore: 1)
J. of Germanic Linguistics     Full-text available via subscription   (Followers: 8, SJR: 0.157, CiteScore: 0)
J. of Global History     Full-text available via subscription   (Followers: 30, SJR: 0.34, CiteScore: 1)
J. of Hellenic Studies     Full-text available via subscription   (Followers: 19, SJR: 0.146, CiteScore: 0)
J. of Helminthology     Hybrid Journal   (Followers: 2, SJR: 0.553, CiteScore: 1)
J. of Hospitality and Tourism Management     Full-text available via subscription   (Followers: 14, SJR: 0.949, CiteScore: 2)
J. of Institutional Economics     Hybrid Journal   (Followers: 15, SJR: 0.978, CiteScore: 2)
J. of K-Theory     Full-text available via subscription  
J. of Laryngology & Otology     Hybrid Journal   (Followers: 21, SJR: 0.495, CiteScore: 1)
J. of Latin American Studies     Hybrid Journal   (Followers: 33, SJR: 0.34, CiteScore: 1)
J. of Law and Religion     Full-text available via subscription   (Followers: 10, SJR: 0.115, CiteScore: 0)
J. of Linguistic Geography     Full-text available via subscription   (Followers: 1)
J. of Linguistics     Hybrid Journal   (Followers: 18, SJR: 0.451, CiteScore: 1)
J. of Management & Organization     Full-text available via subscription   (Followers: 350, SJR: 0.543, CiteScore: 1)
J. of Mechanics     Hybrid Journal   (Followers: 21, SJR: 0.303, CiteScore: 1)
J. of Modern African Studies     Hybrid Journal   (Followers: 20, SJR: 0.606, CiteScore: 1)
J. of Navigation     Hybrid Journal   (Followers: 254, SJR: 0.493, CiteScore: 2)
J. of Nutritional Science     Open Access   (Followers: 3, SJR: 0.984, CiteScore: 2)
J. of Pacific Rim Psychology     Hybrid Journal   (Followers: 1, SJR: 0.33, CiteScore: 1)
J. of Paleontology     Hybrid Journal   (Followers: 11, SJR: 0.882, CiteScore: 2)
J. of Pension Economics & Finance     Hybrid Journal   (Followers: 7, SJR: 0.931, CiteScore: 1)
J. of Plasma Physics     Hybrid Journal   (Followers: 23, SJR: 0.441, CiteScore: 1)
J. of Psychiatric Intensive Care     Hybrid Journal   (Followers: 8)
J. of Psychologists and Counsellors in Schools     Full-text available via subscription   (Followers: 8, SJR: 0, CiteScore: 1)
J. of Public Policy     Hybrid Journal   (Followers: 27, SJR: 0.542, CiteScore: 1)
J. of Race, Ethnicity, and Politics     Full-text available via subscription   (Followers: 4)
J. of Radiotherapy in Practice     Hybrid Journal   (Followers: 7, SJR: 0.16, CiteScore: 0)
J. of Relationships Research     Hybrid Journal   (Followers: 5, SJR: 0.294, CiteScore: 0)
J. of Roman Archaeology     Hybrid Journal   (Followers: 22, SJR: 0.341, CiteScore: 1)
J. of Roman Studies     Full-text available via subscription   (Followers: 22, SJR: 0.182, CiteScore: 0)
J. of Smoking Cessation     Hybrid Journal   (Followers: 6, SJR: 0.411, CiteScore: 0)
J. of Social Policy     Hybrid Journal   (Followers: 42, SJR: 1.063, CiteScore: 2)
J. of Southeast Asian Studies     Full-text available via subscription   (Followers: 12, SJR: 0.14, CiteScore: 0)
J. of Symbolic Logic     Hybrid Journal   (Followers: 1, SJR: 1.057, CiteScore: 1)
J. of the American Philosophical Association     Hybrid Journal   (SJR: 0.857, CiteScore: 1)
J. of the Australian Mathematical Society     Full-text available via subscription   (SJR: 0.46, CiteScore: 1)
J. of the Gilded Age and Progressive Era     Full-text available via subscription   (Followers: 8, SJR: 0.192, CiteScore: 0)
J. of the History of Economic Thought     Full-text available via subscription   (Followers: 14, SJR: 0.784, CiteScore: 1)
J. of the Institute of Mathematics of Jussieu     Hybrid Journal   (SJR: 2.393, CiteScore: 1)
J. of the Intl. Neuropsychological Society     Hybrid Journal   (Followers: 15, SJR: 1.408, CiteScore: 3)
J. of the Intl. Phonetic Association     Full-text available via subscription   (Followers: 2, SJR: 0.27, CiteScore: 1)
J. of the Marine Biological Association of the UK     Hybrid Journal   (Followers: 23, SJR: 0.548, CiteScore: 1)
J. of the Royal Asiatic Society     Hybrid Journal   (Followers: 14, SJR: 0.121, CiteScore: 0)
J. of the Society for American Music     Hybrid Journal   (Followers: 10, SJR: 0.199, CiteScore: 0)
J. of Tropical Ecology     Hybrid Journal   (Followers: 14, SJR: 0.626, CiteScore: 1)
J. of Tropical Psychology     Hybrid Journal   (Followers: 1)
J. of Wine Economics     Full-text available via subscription   (Followers: 5)
Japanese J. of Political Science     Hybrid Journal   (Followers: 8, SJR: 0.372, CiteScore: 1)
Kantian Review     Full-text available via subscription   (Followers: 3)
Knowledge Engineering Review     Hybrid Journal   (Followers: 2, SJR: 0.357, CiteScore: 2)
Language and Cognition     Hybrid Journal   (Followers: 22)
Language in Society     Hybrid Journal   (Followers: 22, SJR: 1.466, CiteScore: 2)
Language Teaching     Hybrid Journal   (Followers: 33, SJR: 1.233, CiteScore: 2)
Language Variation and Change     Hybrid Journal   (Followers: 9, SJR: 0.854, CiteScore: 1)
Laser and Particle Beams     Hybrid Journal   (Followers: 2, SJR: 0.497, CiteScore: 1)
Law and History Review     Full-text available via subscription   (Followers: 15, SJR: 0.184, CiteScore: 0)
Legal Information Management     Hybrid Journal   (Followers: 10)
Legal Theory     Hybrid Journal   (Followers: 14, SJR: 0.484, CiteScore: 1)
Leiden J. of Intl. Law     Hybrid Journal   (Followers: 39, SJR: 0.482, CiteScore: 0)
Libyan Studies     Hybrid Journal   (Followers: 1, SJR: 0.111, CiteScore: 0)
LMS J. of Computation and Mathematics     Free   (SJR: 0.229, CiteScore: 1)
Macroeconomic Dynamics     Hybrid Journal   (Followers: 25, SJR: 1.169, CiteScore: 1)
Management and Organization Review     Hybrid Journal   (Followers: 12, SJR: 0.816, CiteScore: 2)
Mathematical Proceedings of the Cambridge Philosophical Society     Full-text available via subscription   (Followers: 1, SJR: 1.086, CiteScore: 1)
Mathematical Structures in Computer Science     Hybrid Journal   (Followers: 3, SJR: 0.298, CiteScore: 1)
Medical History     Hybrid Journal   (Followers: 8, SJR: 0.417, CiteScore: 1)
Microscopy and Microanalysis     Full-text available via subscription   (Followers: 2, SJR: 0.292, CiteScore: 0)
Modern Asian Studies     Hybrid Journal   (Followers: 16, SJR: 0.397, CiteScore: 0)
Modern Intellectual History     Hybrid Journal   (Followers: 16, SJR: 0.218, CiteScore: 0)
MRS Communications     Hybrid Journal   (SJR: 1.443, CiteScore: 3)
MRS Energy & Sustainability - A Review J.     Full-text available via subscription  
Nagoya Mathematical J.     Hybrid Journal   (SJR: 0.892, CiteScore: 1)
Natural Language Engineering     Hybrid Journal   (Followers: 4, SJR: 0.264, CiteScore: 1)
Netherlands J. of Geosciences     Hybrid Journal   (SJR: 0.285, CiteScore: 1)
Netherlands Yearbook of Intl. Law     Full-text available via subscription   (Followers: 15, SJR: 0.196, CiteScore: 0)
Network Science     Hybrid Journal   (Followers: 5, SJR: 0.461, CiteScore: 1)
Neuron Glia Biology     Hybrid Journal  
New Perspectives on Turkey     Full-text available via subscription   (Followers: 3, SJR: 0.111, CiteScore: 0)
New Surveys in the Classics     Full-text available via subscription   (Followers: 3)
New Testament Studies     Hybrid Journal   (Followers: 33, SJR: 0.316, CiteScore: 0)
New Theatre Quarterly     Hybrid Journal   (Followers: 15, SJR: 0.132, CiteScore: 0)
Nineteenth-Century Music Review     Hybrid Journal   (Followers: 6, SJR: 0.1, CiteScore: 0)
Nordic J. of Linguistics     Hybrid Journal   (Followers: 8, SJR: 0.156, CiteScore: 0)
Numerical Mathematics : Theory, Methods and Applications     Full-text available via subscription  
Nurse Prescriber     Full-text available via subscription   (Followers: 5)
Nutrition Research Reviews     Hybrid Journal   (Followers: 13, SJR: 1.756, CiteScore: 5)
Organised Sound     Hybrid Journal   (Followers: 8, SJR: 0.271, CiteScore: 0)
Oryx     Hybrid Journal   (Followers: 19, SJR: 0.981, CiteScore: 2)
Paleobiology     Full-text available via subscription   (Followers: 6, SJR: 1.563, CiteScore: 3)
Palliative & Supportive Care     Hybrid Journal   (Followers: 34, SJR: 0.611, CiteScore: 1)
Papers of the British School at Rome     Full-text available via subscription   (Followers: 19, SJR: 0.13, CiteScore: 0)
Parasitology     Hybrid Journal   (Followers: 4, SJR: 1.194, CiteScore: 2)
Parasitology Open     Open Access  
Personality Neuroscience     Open Access  
Perspectives on Politics     Full-text available via subscription   (Followers: 42, SJR: 2.075, CiteScore: 2)
Philosophy     Full-text available via subscription   (Followers: 14, SJR: 0.331, CiteScore: 0)
Phonology     Hybrid Journal   (Followers: 9, SJR: 0.623, CiteScore: 1)
Plainsong and Medieval Music     Hybrid Journal   (Followers: 8, SJR: 0.114, CiteScore: 0)
Plant Genetic Resources     Hybrid Journal   (Followers: 3, SJR: 0.353, CiteScore: 1)
Polar Record     Hybrid Journal   (Followers: 2, SJR: 0.313, CiteScore: 1)
Political Science Research and Methods     Full-text available via subscription   (Followers: 22)
Politics & Gender     Full-text available via subscription   (Followers: 25, SJR: 0.861, CiteScore: 1)
Politics and Religion     Full-text available via subscription   (Followers: 9, SJR: 0.541, CiteScore: 1)
Popular Music     Hybrid Journal   (Followers: 20, SJR: 0.216, CiteScore: 0)
Powder Diffraction     Full-text available via subscription   (Followers: 1, SJR: 0.319, CiteScore: 1)
Prehospital and Disaster Medicine     Full-text available via subscription   (Followers: 9, SJR: 0.462, CiteScore: 1)
Primary Health Care Research & Development     Open Access   (Followers: 18, SJR: 0.52, CiteScore: 1)
Probability in the Engineering and Informational Sciences     Hybrid Journal   (Followers: 1, SJR: 0.406, CiteScore: 1)
Proceedings of the Edinburgh Mathematical Society     Hybrid Journal   (SJR: 0.695, CiteScore: 1)
Proceedings of the Intl. Astronomical Union     Full-text available via subscription   (Followers: 2, SJR: 0.117, CiteScore: 0)
Proceedings of the Nutrition Society     Hybrid Journal   (Followers: 8, SJR: 1.373, CiteScore: 4)
Proceedings of the Prehistoric Society     Hybrid Journal   (Followers: 9)
Proceedings of the Royal Society of Edinburgh Section A Mathematics     Full-text available via subscription   (SJR: 1.506, CiteScore: 1)
Progress in Neurotherapeutics and Neuropsychopharmacology     Full-text available via subscription  
PS: Political Science & Politics     Full-text available via subscription   (Followers: 38, SJR: 0.665, CiteScore: 1)
Psychological Medicine     Hybrid Journal   (Followers: 18, SJR: 3.274, CiteScore: 5)
Public Health Nutrition     Hybrid Journal   (Followers: 23, SJR: 1.122, CiteScore: 2)
Publications of the Astronomical Society of Australia     Hybrid Journal   (Followers: 2, SJR: 1.237, CiteScore: 2)
Quarterly Reviews of Biophysics     Hybrid Journal   (Followers: 3, SJR: 3.282, CiteScore: 6)
Quaternary Research     Full-text available via subscription   (Followers: 19, SJR: 1.216, CiteScore: 2)
Queensland Review     Full-text available via subscription   (SJR: 0.101, CiteScore: 0)
Radiocarbon     Hybrid Journal   (Followers: 9, SJR: 0.959, CiteScore: 2)
Ramus : Critical Studies in Greek and Roman Literature     Hybrid Journal   (Followers: 5, SJR: 0.201, CiteScore: 0)
ReCALL     Hybrid Journal   (Followers: 4, SJR: 2.813, CiteScore: 3)
Religious Studies     Hybrid Journal   (Followers: 12, SJR: 0.172, CiteScore: 0)
Renewable Agriculture and Food Systems     Hybrid Journal   (Followers: 15, SJR: 0.593, CiteScore: 2)
Review of Intl. Studies     Full-text available via subscription   (Followers: 27, SJR: 1.63, CiteScore: 2)
Review of Middle East Studies     Full-text available via subscription   (Followers: 10, SJR: 0.101, CiteScore: 0)
Review of Politics     Full-text available via subscription   (Followers: 5, SJR: 0.119, CiteScore: 0)
Review of Symbolic Logic     Full-text available via subscription   (Followers: 2, SJR: 1.049, CiteScore: 1)
Reviews in Clinical Gerontology     Hybrid Journal   (Followers: 5)
Revista de Historia Económica     Full-text available via subscription   (Followers: 1, SJR: 0.221, CiteScore: 0)
Revista Internacional de la Cruz Roja     Full-text available via subscription   (Followers: 2)
Robotica     Hybrid Journal   (Followers: 3, SJR: 0.375, CiteScore: 1)
Royal Institute of Philosophy Supplements     Full-text available via subscription   (Followers: 4)
Rural History     Hybrid Journal   (Followers: 14, SJR: 0.145, CiteScore: 0)
Science in Context     Hybrid Journal   (Followers: 3, SJR: 0.265, CiteScore: 0)
Scottish J. of Theology     Hybrid Journal   (Followers: 38, SJR: 0.177, CiteScore: 0)
Seed Science Research     Hybrid Journal   (Followers: 2, SJR: 0.95, CiteScore: 2)
Slavic Review     Hybrid Journal   (Followers: 8, SJR: 0.395, CiteScore: 1)
Social Philosophy and Policy     Full-text available via subscription   (Followers: 22, SJR: 0.253, CiteScore: 1)
Social Policy and Society     Hybrid Journal   (Followers: 189, SJR: 0.653, CiteScore: 1)
Social Science History     Full-text available via subscription   (Followers: 16, SJR: 0.2, CiteScore: 0)
Spanish J. of Psychology     Hybrid Journal  
Studies in American Political Development     Hybrid Journal   (Followers: 6, SJR: 0.204, CiteScore: 0)
Studies in Church History     Full-text available via subscription   (Followers: 1)
Studies in Second Language Acquisition     Hybrid Journal   (Followers: 41, SJR: 1.516, CiteScore: 2)
Tempo     Hybrid Journal   (Followers: 2, SJR: 0.151, CiteScore: 0)
Thalamus & Related Systems     Full-text available via subscription  
The Americas : A Quarterly Review of Latin American History     Full-text available via subscription   (Followers: 5, SJR: 0.305, CiteScore: 0)
The Lichenologist     Hybrid Journal   (Followers: 5, SJR: 1.113, CiteScore: 2)
The Mathematical Gazette     Full-text available via subscription   (Followers: 1)
Theatre Research Intl.     Full-text available via subscription   (Followers: 14, SJR: 0.204, CiteScore: 0)
Theatre Survey     Full-text available via subscription   (Followers: 11, SJR: 0.121, CiteScore: 0)
Theory and Practice of Logic Programming     Hybrid Journal   (Followers: 3, SJR: 0.524, CiteScore: 2)
Think     Full-text available via subscription   (Followers: 6)
TRaNS : Trans-Regional-and-National Studies of Southeast Asia     Full-text available via subscription   (Followers: 6, SJR: 0.192, CiteScore: 0)
Transactions of the Royal Historical Society     Hybrid Journal   (Followers: 15, SJR: 0.419, CiteScore: 0)
Transnational Environmental Law     Hybrid Journal   (Followers: 5, SJR: 0.498, CiteScore: 1)
Twentieth-century music     Hybrid Journal   (Followers: 4, SJR: 0.453, CiteScore: 1)
Twin Research and Human Genetics     Full-text available via subscription   (SJR: 0.72, CiteScore: 1)
Urban History     Hybrid Journal   (Followers: 18, SJR: 0.358, CiteScore: 0)
Utilitas     Hybrid Journal   (Followers: 8, SJR: 0.712, CiteScore: 0)
Victorian Literature and Culture     Hybrid Journal   (Followers: 21, SJR: 0.163, CiteScore: 0)
Visual Neuroscience     Hybrid Journal   (Followers: 7, SJR: 1.012, CiteScore: 2)
Wireless Power Transfer     Full-text available via subscription   (Followers: 4)
World Politics     Hybrid Journal   (Followers: 213, SJR: 6.544, CiteScore: 4)
World Trade Review     Full-text available via subscription   (Followers: 17, SJR: 0.591, CiteScore: 1)
World's Poultry Science J.     Full-text available via subscription   (Followers: 5, SJR: 0.559, CiteScore: 1)
Yearbook of Intl. Humanitarian Law     Full-text available via subscription   (Followers: 8, SJR: 0.107, CiteScore: 0)
Zygote     Hybrid Journal   (Followers: 1, SJR: 0.387, CiteScore: 1)

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Similar Journals
Journal Cover
Proceedings of the International Astronomical Union
Journal Prestige (SJR): 0.117
Number of Followers: 2  
  Full-text available via subscription Subscription journal
ISSN (Print) 1743-9213 - ISSN (Online) 1743-9221
Published by Cambridge University Press Homepage  [387 journals]
  • IAU volume 14 issue 353 Cover and Front matter
    • Authors: Monica Valluri; J. A. Sellwood
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921320000964
      Issue No: Vol. 14, No. S353 (2019)
  • IAU volume 14 issue 353 Cover and Back matter
    • Authors: Monica Valluri; J. A. Sellwood
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921320000976
      Issue No: Vol. 14, No. S353 (2019)
  • Milky Way’s structure based on thousands of Cepheids and RR Lyrae
           stars from OGLE
    • Authors: Pawel Pietrukowicz; Monica Valluri, J. A. Sellwood
      Pages: 1 - 5
      Abstract: Classical Cepheids and RR Lyrae-type variable stars are widely-used tracers of young (< 300 Myr) and old (> 10 Gyr) stellar populations, respectively. These stars also serve as distance indicators allowing for Galactic structure studies. Robust detection of pulsating variables requires precise and relatively frequent observations over several years. Recently, the OGLE survey has discovered nearly 1,300 new genuine classical Cepheids and 15,000 RR Lyrae stars along the southern Galactic plane. Here, we present the picture of the Milky Way’s thin disk drawn with the Cepheids and the view of the Galactic old population that emerges from the set of known RR Lyrae stars.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008512
      Issue No: Vol. 14, No. S353 (2019)
  • A 3D map of the Milky Way’s disk as traced by classical Cepheids
    • Authors: Xiaodian Chen; Shu Wang, Licai Deng, Richard de Grijs, Chao Liu, Hao Tian, Monica Valluri, J. A. Sellwood
      Pages: 6 - 9
      Abstract: We have collected 2330 Cepheids to establish an intuitive 3D map of the Milky Way’s disk. As regards the warp amplitude, the Cepheid disk agrees well with the gas disk for radii up to 15 kpc. However, the mean line of nodes (LON) of the Cepheid disk deviates from the Galactic Center–Sun direction by 17.5±1.0°. This is a new and different result compared with previous results. The LON is not stable at any given radius, but it twists. The twisted pattern suggests that the formation of the Milky Way’s warp is dominated by the massive inner disk. The kinematic warp defined by the Cepheids is also in concordance with the spatial warp. In the 2020 era, the anticipated increasing number of new Cepheids will provide a key opportunity to view our Milky Way’s disk as a whole, and we expect that our knowledge of the disk’s main structural features will be much improved.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S174392131900869X
      Issue No: Vol. 14, No. S353 (2019)
  • Dissecting the phase space snail shell
    • Authors: Zhao-Yu Li; Juntai Shen, Monica Valluri, J. A. Sellwood
      Pages: 10 - 12
      Abstract: The on-going phase mixing in the vertical direction of the Galactic disk has been discovered with the revolutionary Gaia DR2 data. It manifests itself as the snail shell in the Z–Vz phase space. To better understand the origin and properties of the phase mixing process, we study the phase-mixing signatures in moving groups (also known as the kinematic streams) with the Gaia DR2 data in the Galactic disk near the Solar circle. Interestingly, the phase space snail shell exists only in the main kinematic streams with |VR|≲ 50 km/s and |Vφ –VLSR|≲30 km/s, i.e., stars on dynamically “colder” orbits. Compared to the colder orbits, the hotter orbits may have phase-wrapped away already due to the much larger dynamical range in radial variation to facilitate faster phase mixing. These results help put tighter constraints on the vertical perturbation history of the Milky Way disk. To explain the lack of a well-defined snail shell in the hotter orbits, the disk should have been perturbed at least ∼400–500 Myr ago. Our results offer more support to the recent satellite-disk encounter scenario than the internal bar buckling perturbation scenario as the origin of the phase space mixing.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008007
      Issue No: Vol. 14, No. S353 (2019)
  • Vertical distribution of stars and flaring in the Milky Way
    • Authors: Suchira Sarkar; Chanda J. Jog, Monica Valluri, J. A. Sellwood
      Pages: 13 - 15
      Abstract: We study the vertical stellar distribution of the Milky Way thin disk treated as a gravitationally coupled system of stars, HI and H2 gas in the field of dark matter halo, from R = 4 to 22 kpc. We show that the gas and halo gravity mainly constrain this vertical distribution toward the mid-plane in the inner and the outer Galaxy, respectively. The halo gravity reduces the disk thickness by a factor of 3-4 in the outer Galaxy. Despite this constraining effect the disk thickness increases steadily with radius, flaring steeply beyond 17 kpc, making a flaring disk a generic result.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008019
      Issue No: Vol. 14, No. S353 (2019)
  • GALAH+and+Gaia+surveys&rft.title=Proceedings+of+the+International+Astronomical+Union&rft.issn=1743-9213&,+Monica+Valluri,+J.+A.+Sellwood&rft_id=info:doi/10.1017/S1743921319008597">Lithium enrichment in the Galaxy: A study using the GALAH and Gaia surveys
    • Authors: Deepak; Bacham E. Reddy, Monica Valluri, J. A. Sellwood
      Pages: 16 - 18
      Abstract: Here, we explore the enrichment of Lithium in the Galaxy using a large sample of stars common among large spectroscopic surveys such as the GALAH and astrometric survey by the Gaia satellite. For this study we used about 60,000 low mass (M⩽ 2M⊙) dwarfs from the GALAH survey. Further, we discuss Li enrichment among giant stars based on a sample of 52,000 low mass giants, of which 335 are Li-rich with A(Li) ⩾ 1.80 ± 0.14 dex, culled from the GALAH survey. These low mass giants appears to be one of the promising source of Li enrichment in the Galaxy as their atmospheric Li can be added to the ISM through mass loss.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008597
      Issue No: Vol. 14, No. S353 (2019)
  • 3D asymmetrical kinematics of mono-age populations from LAMOST and Gaia
           common red clump stars
    • Authors: H.-F. Wang; Martn López-Corredoira, Y. Huang, Jeffrey L. Carlin, Monica Valluri, J. A. Sellwood
      Pages: 19 - 21
      Abstract: With the LAMOST DR4 and Gaia DR2 common red clump giant stars, we investigate the three-dimensional kinematics of Milky Way disk stars in mono-age populations between Galactocentric distances of R = 6 and 15 kpc. We confirm the 3D asymmetrical motions of recent works, and provide time tagging of the Galactic outer disk asymmetrical motions. Radial motions present a north-south asymmetry in the region corresponding to recent density and velocity substructures that were sensitive to the perturbations in the early 6 Gyr. What’s more, we discover a new velocity substructure in the north side corresponding to density dip found recently (“south-middle opposite”) in the radial and azimuthal velocity. Meanwhile, the vertical velocity with clear vertical bulk motions or bending mode motions has no clear asymmetry corresponding to the in-plane asymmetrical features.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008044
      Issue No: Vol. 14, No. S353 (2019)
  • Study of open cluster NGC 5617 in Gaia era
    • Authors: D. Bisht; Qingfeng Zhu, Monica Valluri, J. A. Sellwood
      Pages: 22 - 23
      Abstract: Identification of member stars in open clusters is still an open question. Thanks to Gaia DR2 data base, which improves our statistics regarding true members in clusters to understand cluster properties much better way. In this paper, we identify the cluster members using proper motion and colour magnitude diagram for NGC 5617. In addition to this, we have determined more precise fundamental parameters as well.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008159
      Issue No: Vol. 14, No. S353 (2019)
  • Something about Red Supergiants
    • Authors: Maria Messineo; Monica Valluri, J. A. Sellwood
      Pages: 24 - 25
      Abstract: I would like to present an overview of red supergiants (RSGs) in the Milky Way. There are only about 1400 objects listed as RSGs in the spectroscopic catalog by Skiff (2014); moreover, we are not sure yet about how they formed and where they formed. Indeed, most of them are strangely found in isolation, while extraordinary massive clusters of RSGs are observed at the near-end of the Galactic Bar. This intriguing overdensity poses some questions about the continuity of star formation in the Galactic Disk.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008482
      Issue No: Vol. 14, No. S353 (2019)
  • Dynamics of the Milky Way Bar/Bulge
    • Authors: Ortwin Gerhard; Monica Valluri, J. A. Sellwood
      Pages: 26 - 28
      Abstract: Stellar surveys and dynamical models have recently led to important progress on understanding the dynamical structure of the Milky Way’s bar and central box/peanut bulge. This talk briefly reviews the density structure of the bulge and bar from star count tomography, the cylindrical rotation of bulge stars, and the measurements of their stellar masses and pattern speed that have been obtained by fitting dynamical models to the combined star count and line-of-sight velocity data. Recent work deriving absolute proper motions throughout the bulge from the VIRAC survey and Gaia has led to a new 3D measurement of the barred bulge kinematics which is expected to greatly improve the dynamical models, and has already confirmed the relatively slow pattern speed (∼40 kms−1 kpc−1) obtained from the previous dynamical and gas-dynamical modelling.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008809
      Issue No: Vol. 14, No. S353 (2019)
  • New VIRAC proper motion maps show signature of galactic boxy/peanut bulge
    • Authors: Jonathan P. Clarke; Christopher Wegg, Ortwin Gerhard, Leigh C. Smith, Phil W. Lucas, Shola M. Wylie, Monica Valluri, J. A. Sellwood
      Pages: 29 - 30
      Abstract: We have derived absolute proper motions of stars in the Galactic bulge region combining the VVV InfraRed Astrometric Catalogue (VIRAC) and Gaia. We use the proper motions to study the kinematic structure of the bulge both integrated along the line-of-sight and in magnitude intervals using red clump stars as standard candles. In parallel we compare to a made-to-measure barred dynamical model, folding in the VIRAC selection function, to understand and interpret the structures that we observe. The barred dynamical model, which contains a boxy/peanut bulge, and has a pattern speed of 37.5 kms−1 kpc−1, is able to reproduce all structures impressively well.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008779
      Issue No: Vol. 14, No. S353 (2019)
  • The VVV Survey: Globular Clusters and more
    • Authors: Dante Minniti; María Gabriela Navarro, Monica Valluri, J. A. Sellwood
      Pages: 31 - 34
      Abstract: In the efforts to map the Milky Way structure, the central regions have remained very difficult to probe. The VISTA Variables in the Vía Láctea Survey (VVV) is a near-IR variability Survey that scans 560 sq.deg. across the Milky Way bulge and an adjacent section of the southern mid-plane. The main goal of the VVV Survey is to build a 3D map of the structure of the inner Galaxy and characterize its stellar populations. This survey has discovered different kinds of objects, such as globular clusters, Microlensing events, RR Lyrae stars, Cepheids, WITs, among others. The extension of the Survey (VVVX) is observing until 2020, tripling the areal coverage, and complementing the variability studies done by the VVV Survey.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008731
      Issue No: Vol. 14, No. S353 (2019)
  • VVV Microlensing events in the far side of the Milky Way
    • Authors: María Gabriela Navarro; Dante Minniti, Rodrigo Contreras Ramos, Monica Valluri, J. A. Sellwood
      Pages: 35 - 37
      Abstract: In order to study the most reddened areas of the Milky Way we used near-IR data from the VVV Survey. For the first time, the VISTA telescope allows us to observe the mid-plane through the Galactic bulge and study the disk in the other side of the Milky Way. Motivated by the detection of hundreds of microlensing events in the inner regions of the Galaxy, we propose three new configurations of microlensing events, placing the sources in the far-disk and the lenses in the far-disk/bulge/near-disk. These new configurations will change the usual way to interpret the timescale distributions due to the different populations along the line of sight, that exhibit varied transverse velocities and relative distances.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S174392131900872X
      Issue No: Vol. 14, No. S353 (2019)
  • Transverse bar/bulge kinematics with Gaia and VVV
    • Authors: Jason L. Sanders; N. Wyn Evans, Leigh Smith, Philip Lucas, Monica Valluri, J. A. Sellwood
      Pages: 38 - 42
      Abstract: We present new results on the Galactic bar/bulge transverse velocity structure using Gaia and the VISTA Variables in Via Lactea (VVV) survey. Gaia is complemented in high extinction regions by the multi-epoch infrared VVV observations for which derived relative proper motions can be tied to Gaia’s absolute frame. We extract kinematic maps (both 2D and 3D) of the Galactic bar/bulge, from which we measure the pattern speed of the bar using a novel technique. We focus on the evidence of an X-shaped bulge from the kinematic maps.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008664
      Issue No: Vol. 14, No. S353 (2019)
  • Stellar populations in the BAaDE survey
    • Authors: Megan O. Lewis; Ylva M. Pihlström, Loránt O. Sjouwerman, Michael C. Stroh, Monica Valluri, J. A. Sellwood
      Pages: 43 - 44
      Abstract: The BAaDE (Bulge Asymmetries and Dynamical Evolution) project is an SiO maser survey of the Galactic Plane. About 19,000 sources have been observed at 43 GHz with the VLA, and the production of spectra for each of these sources is well underway. The primary goal of the project is to collect line-of-sight velocities for all the detected masers in the sample to probe Galactic dynamics. With an expected detection rate of over 60% we should collect over 11,000 velocities to probe the Galactic potential. The survey is also a large sample of infrared sources to explore the different evolved stellar populations within the Milky Way. So far we discern three distinct groups in the BAaDE sample: the main group containing oxygen-rich, evolved stars with a high SiO maser detection rate, a much smaller population of carbon-rich evolved stars, and finally a group of likely young stellar objects with no maser emission. These populations are separated using 2MASS and MSX color-color diagrams, and we find a particularly useful cut between the young and evolved objects using the MSX [D] –[E] color. Identification of these populations will isolate BAaDE’s evolved star sample, and will more tightly define the region in IR color-color diagrams where SiO masers occur yielding a better understanding of these kinematical probes. Using our color-divisions we can also study the distribution of each of the populations within the Galactic Plane.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008111
      Issue No: Vol. 14, No. S353 (2019)
  • BAaDE: The Bulge Asymmetries and Dynamical Evolution survey
    • Authors: Loránt O. Sjouwerman; Ylva M. Pihlström, Michael C. Stroh, Megan O. Lewis, Mark J Claussen, Adam C. Trapp, R. Michael Rich, Mark R. Morris, Monica Valluri, J. A. Sellwood
      Pages: 45 - 46
      Abstract: The Bulge Asymmetries and Dynamical Evolution (BAaDE) survey aims to use circumstellar SiO maser line-of-sight velocities as probes for the Galactic gravitational potential and dynamical structure. The SiO masers are detected at a high rate in specific color-selected MSX infrared sources. Furthermore, the SiO maser properties and line ratios, in combination with infrared spectral energy distributions and location in the Galaxy, will statistically yield detailed information on population and evolution of low- to intermediate-mass evolved stars in the Galaxy.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008147
      Issue No: Vol. 14, No. S353 (2019)
  • SiO maser emission as a stellar line-of-sight velocity tracer in the Bulge
           Asymmetries and Dynamical Evolution (BAaDE) survey
    • Authors: Michael C. Stroh; Ylva M. Pihlström, Loránt O. Sjouwerman, Megan O. Lewis, Mark J Claussen, Mark R. Morris, R. Michael Rich, Monica Valluri, J. A. Sellwood
      Pages: 47 - 48
      Abstract: The Bulge Asymmetries and Dynamical Evolution (BAaDE) survey aims to explore the complex structure of the inner Galaxy and Galactic Bulge, by using the 43 GHz receivers at the Karl G. Jansky Very Large Array (VLA) and the 86 GHz receivers at the Atacama Large Millimeter/submillimeter Array (ALMA) to observe SiO maser lines in red giant stars. The goal is to construct a sample of stellar point-mass probes that can be used to test models of the gravitational potential, and the final sample is expected to provide at least 20,000 line-of-sight velocities and positions. A possible bias between the VLA and the ALMA SiO maser lines is explored, and the 86 GHz SiO line-peak velocities agree using either of the four sampled lines. Additionally, the SiO maser velocities agree with the OH maser derived velocities.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319009268
      Issue No: Vol. 14, No. S353 (2019)
  • Measuring torque of galactic bar from Gaia DR2
    • Authors: Rain Kipper; Elmo Tempel, Monica Valluri, J. A. Sellwood
      Pages: 49 - 50
      Abstract: Since past few decades, observations have improved so strongly that when modelling Milky Way (MW) dynamics it is required to include small perturbations to the modelling process. It is difficult task that we try to solve by selecting regions to model so small that the perturbation can be considered to give nearly constant effect. We use Solar Neighbourhood (SN) as our test sample and assume that the bar effects show more or less constant contribution to SN. By extrapolating and smoothing observed stars on their orbits, and requiring that smoothed and observed phase space are consistent we were able to deduce acceleration vector. We conclude from non-radial acceleration component that the bar must cause about one third of total acceleration near SN.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008561
      Issue No: Vol. 14, No. S353 (2019)
  • Infrared space astrometry mission for survey of the Galactic nuclear
           bulge: Small-JASMINE
    • Authors: Naoteru Gouda; Monica Valluri, J. A. Sellwood
      Pages: 51 - 53
      Abstract: Small-JASMINE will provide astrometric data with high precisions in a near infrared band for stars in the Galactic nuclear bulge and other specific targets. The primary scientific objective is to carry out the Galactic Center Archeology by exploring the Galactic nuclear bulge that leads to the elucidation of the Galactic structures and the evolution of the supermassive black hole at the center. Small-JASMINE has been selected as the unique candidate for the competitive 3rd M-class science satellite mission by ISAS/JAXA. The launch date is mid-2020s.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319007968
      Issue No: Vol. 14, No. S353 (2019)
  • Nearby Hills ejecta as a probe of the gravitational potential of the Milky
    • Authors: Y. Q. Zhang; M. C. Smith, P. J. McMillan, Monica Valluri, J. A. Sellwood
      Pages: 54 - 56
      Abstract: Stars ejected from the Galactic Center can be used to place important constraints on the Milky Way potential. We have used Hills stars to constrain models for the Galactic potential, demonstrating that meaningful constraint can be obtained if we have samples of around 50 nearby Hills stars.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008317
      Issue No: Vol. 14, No. S353 (2019)
  • Tracing the rotational velocity of the halo with K-giant stars in
           LAMOST-Gaia era
    • Authors: Hao Tian; Chao Liu, Yan Xu, Xiang-Xiang Xue, Monica Valluri, J. A. Sellwood
      Pages: 57 - 58
      Abstract: LAMOST has obtained a large number of spectra for K-giant stars whose metallicities are well measured and released in DR5. Combining with the distances, radial velocities and proper motions provided by Gaia DR2, the full position and velocity information has been obtained. Using the Bayesian method we have constrained the rotational velocity of the halo and thick disk components in the local volume within 4 kpc from the Sun. The values of the rotational velocity are and for the halo and disk respectively, with the velocity of LSR assumed to be 232 km s−1. The dispersions of the rotational velocity are and for the two components. What’s more, another hot retrogradely rotating component is discovered.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008688
      Issue No: Vol. 14, No. S353 (2019)
  • The high transverse velocity stars in Gaia-LAMOST
    • Authors: João A. S. Amarante; Martin C. Smith, Corrado Boeche, Monica Valluri, J. A. Sellwood
      Pages: 59 - 60
      Abstract: Although the stellar halo accounts for just ∼1% of the total stellar mass of the Milky Way, the kinematics of halo stars can tell us a lot about the origins and evolution of our Galaxy. It has been shown that the high transverse velocity stars in Gaia DR2 reveal a double sequence in the Hertzsprung-Russell (HR) diagram, indicating a duality in the local halo within 1 kpc. We fit these stars by updating the popular Besançon/Galaxia model, incorporating the latest observational results for the stellar halo. We are able to obtain a good match to the Gaia data and provide new constraints on the properties of the disc and halo. In particular, we show that the thick disc contribution to this high velocity tail is small, but not negligible, and likely has an influence on the red sequence of the HR diagram.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008603
      Issue No: Vol. 14, No. S353 (2019)
  • Constraining the Milky Way non-axisymmetries with Gaia
    • Authors: B. Famaey; G. Monari, A. Siebert, O. Bienaymé, R. Ibata, C. Wegg, O. Gerhard, Monica Valluri, J. A. Sellwood
      Pages: 61 - 64
      Abstract: The unprecedented amount and accuracy of kinematic data from the second release of the Gaia mission have started revolutionizing our understanding of the dynamics of the Milky Way disk. The detailed stellar velocity field in the Galactic disk should allow us to constrain with unprecedented precision the parameters of the non-axisymmetric modes of the disk. We present here the status of our current modelling efforts in this area, and their implication on the dynamics of the Galactic bar in particular.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008536
      Issue No: Vol. 14, No. S353 (2019)
  • Warps, Waves, and Phase Spirals in the Milky Way
    • Authors: Lawrence M. Widrow; Keir Darling, Haochuan Li, Monica Valluri, J. A. Sellwood
      Pages: 65 - 70
      Abstract: The stellar disc of the Milky Way exhibits clear departures from planarity, the most conspicuous manifestation being the Galactic Warp but also includes an apparent corrugation pattern in number counts around 15kpc from the Galactic centre, a wave like pattern in the vertical velocities of stars as a function of guiding radius, asymmetries about the midplane in both number counts and bulk motions, and phase spirals in the z–vz projection of the local stellar distribution function. We discuss the physics of these phenomena and, in particular, suggest a possible avenue for inferring the vertical force in the Solar Neighbourhood from phase spirals. We apply Dynamic Mode Decomposition, a technique widely used in the realm of fluid mechanics, to simulations of disc galaxy simulations. This method appears to be particularly well-suited to the study of nonlinear processes such as the coupling of warps and spirals, first discussed by Masset and Tagger.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319009049
      Issue No: Vol. 14, No. S353 (2019)
  • Kinematics of highly r-process-enhanced halo stars: Evidence for origins
           in now-destroyed ultra-faint dwarf galaxies
    • Authors: Kaley Brauer; Alexander P. Ji, Kohei Hattori, Sergio Escobar, Anna Frebel, Monica Valluri, J. A. Sellwood
      Pages: 71 - 74
      Abstract: The Milky Way’s stellar halo preserves a fossil record of smaller dwarf galaxies that merged with the Milky Way throughout its formation history. Currently, though, we lack reliable ways to identify which halo stars originated in which dwarf galaxies or even which stars were definitively accreted. Selecting stars with specific chemical signatures may provide a way forward. We investigate this theoretically and observationally for stars with r-process nucleosynthesis signatures. Theoretically, we combine high-resolution cosmological simulations with an empirically-motivated treatment of r-process enhancement. We find that around half of highly r-process-enhanced metal-poor halo stars may have originated in early ultra-faint dwarf galaxies that merged into the Milky Way during its formation. Observationally, we use Gaia DR2 to compare the kinematics of highly r-process-enhanced halo stars with those of normal halo stars. R-process-enhanced stars have higher galactocentric velocities than normal halo stars, suggesting an accretion origin. If r-process-enhanced stars largely originated in accreted ultra-faint dwarf galaxies, halo stars we observe today could play a key role in understanding the smallest building blocks of the Milky Way via this novel approach of chemical tagging
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008755
      Issue No: Vol. 14, No. S353 (2019)
  • Streams and the Milky Way dark matter halo
    • Authors: Heidi Jo Newberg; Siddhartha Shelton, Eric Mendelsohn, Jake Weiss, Matthew Arsenault, Jacob S. Bauer, Travis Desell, Roland Judd, Malik Magdon-Ismail, Lee A. Newberg, Matthew Newby, Clayton Rayment, Colin Rice, Boleslaw K. Szymanski, Jeffery M. Thompson, Steve Ulin, Carlos Varela, Lawrence M. Widrow, Benjamin A. Willett, Monica Valluri, J. A. Sellwood
      Pages: 75 - 82
      Abstract: We describe an algorithm that can fit the properties of the dwarf galaxy progenitor of a tidal stream, given the properties of that stream. We show that under ideal conditions (the Milky Way potential, the orbit of the dwarf galaxy progenitor, and the functional form of the dwarf galaxy progenitor are known exactly), the density and angular width of stars along the stream can be used to constrain the mass and radial profile of both the stellar and dark matter components of the progenitor dwarf galaxy that was ripped apart to create the stream. Our provisional fit for the parameters of the dwarf galaxy progenitor of the Orphan Stream indicates that it is less massive and has fewer stars than previous works have indicated.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S174392131900855X
      Issue No: Vol. 14, No. S353 (2019)
  • New structures of the Milky Way stellar and dark halos revealed from the
           Subaru/Hyper Suprime-Cam survey
    • Authors: Masashi Chiba; Monica Valluri, J. A. Sellwood
      Pages: 83 - 90
      Abstract: We present the recent discovery of new halo structures in the Milky Way (MW) based on the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP). HSC is a wide-field imager installed at the prime focus of the Subaru Telescope, and a 300-night survey with this instrument is being carried out in this program. The combination of the superb image quality and depth and the fact that it is a multi-band survey allows us to identify new faint satellites as well as field halo stars in the outskirts of the MW halo beyond the reach of previous surveys. We report here on the new insights into the nature of both stellar and dark halos in the MW as revealed from this on-going survey program and show prospects based on the upcoming large spectroscopic survey with Subaru Prime Focus Spectrograph.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008640
      Issue No: Vol. 14, No. S353 (2019)
  • Gaia&rft.title=Proceedings+of+the+International+Astronomical+Union&rft.issn=1743-9213&,+Chao+Liu,+Juntai+Shen,+Chris+Flynn,+Chengqun+Yang,+Monica+Valluri,+J.+A.+Sellwood&rft_id=info:doi/10.1017/S1743921319008299">Galactic mass and anisotropy profile with halo K-giant and blue horizontal
           branch stars from LAMOST/SDSS and Gaia
    • Authors: Sarah A. Bird; Xiang-Xiang Xue, Chao Liu, Juntai Shen, Chris Flynn, Chengqun Yang, Monica Valluri, J. A. Sellwood
      Pages: 91 - 95
      Abstract: A major uncertainty in the determination of the mass profile of the Milky Way using stellar kinematics in the halo is the poorly determined anisotropy parameter, , where σr is the Galactocentric radial velocity dispersion, and σθ and σφ are the tangential components of the velocity dispersion. We have used a sample of over 24,000 Galactic halo K giant and blue horizontal branch stars from the LAMOST stellar spectroscopic survey and SDSS/SEGUE, combined with proper motions from Gaia Data Release 2, to measure β(rgc) over a wide range of Galactocentric distances rgc from 5 to 80 kpc. Kinematic substructures have been carefully removed to reveal the underlying diffuse stellar halo prior to measuring β. We find that orbits are generally radial (β > 0) and β is constant out to distances of about 40 kpc, with a dependence on metallicity of the stars, such that β declines with lower metallicity. Similar behavior is seen in both the K giant and BHB samples.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008299
      Issue No: Vol. 14, No. S353 (2019)
  • The shape of the dark matter halo revealed from a hypervelocity star
    • Authors: Kohei Hattori; Monica Valluri, Monica Valluri, J. A. Sellwood
      Pages: 96 - 100
      Abstract: A recently discovered young, high-velocity giant star J01020100-7122208 is a good candidate of hypervelocity star ejected from the Galactic center, although it has a bound orbit. If we assume that this star was ejected from the Galactic center, it can be used to constrain the Galactic potential, because the deviation of its orbit from a purely radial orbit informs us of the torque that this star has received. Based on this assumption, we estimate the flattening of the Galactic dark matter halo by using the Gaia DR2 data and the circular velocity data. Our Bayesian analysis shows that the orbit of J01020100-7122208 favors a prolate halo within ~ 10 kpc from the Galactic center. The posterior distribution of the density flattening q shows a broad distribution at q ≳ 1 and peaks at q ≃ 1.5. Also, 98.5% of the posterior distribution is located at q > 1, highly disfavoring an oblate halo.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008718
      Issue No: Vol. 14, No. S353 (2019)
  • Modelling our galaxy
    • Authors: James Binney; Monica Valluri, J. A. Sellwood
      Pages: 101 - 108
      Abstract: Dynamical models will be key to exploitation of the incoming flood data for our Galaxy. Modelling techniques are reviewed with an emphasis on f(J) modelling.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008214
      Issue No: Vol. 14, No. S353 (2019)
  • Satellite galaxies as better tracers of the Milky Way halo mass
    • Authors: Jiaxin Han; Wenting Wang, Zhaozhou Li, Monica Valluri, J. A. Sellwood
      Pages: 109 - 112
      Abstract: The inference of the Milky Way halo mass requires modelling the phase space structure of dynamical tracers, with different tracers following different models and having different levels of sensitivity to the halo mass. For steady-state models, deviations from steady-state in the tracer distribution lead to an irreducible stochastic bias. This bias is small for satellite galaxies and dark matter particles, but as large as a factor of 2 for halo stars. This is consistent with the picture that satellite galaxies closely trace the underlying phase space distribution of dark matter particles, while halo stars are less phase-mixed. As a result, the use of only ~100 satellite galaxies can achieve a significantly higher accuracy than that achievable with a much larger sample of halo stars.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008020
      Issue No: Vol. 14, No. S353 (2019)
  • The early merger that made the galaxy’s stellar halo
    • Authors: N. Wyn Evans; Monica Valluri, J. A. Sellwood
      Pages: 113 - 120
      Abstract: The last two years have seen widespread acceptance of the idea that the Milky Way halo was largely created in an early (8-10 Gyr ago) and massive (>1010Mȯ) merger. The roots of this idea pre-date the Gaia mission, but the exquisite proper motions available from Gaia have made the hypothesis irresistible. We trace the history of this idea, reviewing the series of papers that led to our current understanding.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319009700
      Issue No: Vol. 14, No. S353 (2019)
  • Detecting tidal tail of the globular cluster Whiting 1
    • Authors: Jundan Nie; Hao Tian, Monica Valluri, J. A. Sellwood
      Pages: 121 - 122
      Abstract: Whiting 1 is a faint and young globular cluster embedded in the Sag dSph. It has similar distance, metalicity and radial velocity with the trailing stream of the Sag. Due to these special properties, Whiting 1 was suggested to be associated with the trailing stream of Sag. However, its origin is still unclear and further investigation of its relation with Sgr dSph is needed. In this work, we use DECaLS data to search the tidal tail of Whiting 1, with the aim of looking for spatial connection between Whiting 1 and Sgr dSph. With Matched Filter method, we detected a tidal tail around the main body of Whiting 1. This tail extends to at least 0.5 degree and aligns with the mean orbit direction of Sgr dSph. This tail is newly detected and it provides additional evidence of the association between Whiting 1 and Sgr trailing stream.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008639
      Issue No: Vol. 14, No. S353 (2019)
  • The LMC vs. the Milky Way
    • Authors: Gurtina Besla; Nicolás Garavito-Camargo, Monica Valluri, J. A. Sellwood
      Pages: 123 - 127
      Abstract: Recent advancements in astrometry and in cosmological models of dark matter halo growth have significantly changed our understanding of the dynamics of the Local Group. The most dramatic changes owe to a new picture of the structure and dynamics of the Milky Way’s most massive satellite galaxy, the Large Magellanic Cloud (LMC), which is most likely on its first passage about the Milky Way and ten times larger in mass than previously assumed. The LMC’s orbit through the Milky Way’s dark matter and stellar halo will leave characteristic signatures in both density and kinematics. Furthermore, the gravitational perturbations produced by both direct tidal forcing from the LMC and the response of the halo to its passage will together cause significant perturbations to the orbits of tracers of the Milky Way’s dark matter distribution. We advocate for the use of basis field expansion methods to fully capture and quantify these effects.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008494
      Issue No: Vol. 14, No. S353 (2019)
  • Proper motion of the Magellanic Bridge: Removal of foreground stars
    • Authors: Thomas Schmidt; Maria-Rosa L. Cioni, Florian Niederhofer, Jonathan Diaz, Anna B. A. Queiroz, Gal Matijevic, Cristina Chiappini, Monica Valluri, J. A. Sellwood
      Pages: 128 - 129
      Abstract: The Large and Small Magellanic Cloud (LMC and SMC) are the most luminous dwarf galaxy satellites of the Milky Way. Thanks to their close proximity (50-60 kpc), they provide one of the best opportunities to study in detail the kinematics of resolved stellar populations in an interacting pair of galaxies. Large photometric surveys like the ongoing Gaia mission and the near-infrared VISTA survey of the Magellanic Cloud system (VMC) will have a significant impact on our insight into the Magellanic system. We have combined the individual strengths of VMC and Gaia DR2 data to improve our understanding of the internal kinematics of the galaxies. In this study, we present results from our ongoing project dedicated to measure and analyse the proper motions of large samples of stars across the Magellanic Clouds, efficiently removing Milk Way foreground stars utilising distances derived with the StarHorse code.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008135
      Issue No: Vol. 14, No. S353 (2019)
  • Revisiting the innermost kinematics of M31 galaxy with the OMM Fabry-Perot
    • Authors: Sié Zacharie Kam; Claude Carignan, Michel Marcelin, Philippe Amram, Jean Koulidiati, Monica Valluri, J. A. Sellwood
      Pages: 130 - 133
      Abstract: We present observations on optical emission lines acquired with the scanning Fabry-Perot interferometer of the observatoire du Mont Mégantic, of the Andromeda galaxy (M31). A 765 order Fabry-Perot were used with a fast readout EM-CCD. From data obtained, kinematic maps and data points for the rotation curve of the innermost part of the galaxy are derived. Several dozen of regions have been scanned with the Fabry-Perot interferometer and narrow band interference filters. The central 10’x10’ were scanned with five different filters. Observations have been made in order to get better Hα data for kinematics purposes.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008524
      Issue No: Vol. 14, No. S353 (2019)
  • Spirals in galaxies
    • Authors: J. A. Sellwood; Monica Valluri, J. A. Sellwood
      Pages: 134 - 134
      Abstract: The venerable problem of what causes the spiral features in disk galaxies is nearing a solution. In previous work, we have shown that transient spirals in simulations result from the superposition of a few coherent waves that have many properties of modes. The new achievement presented here is a clear demonstration that the evolution of one unstable mode leads to scattering at Lindblad resonances, and the depopulation of phase space at such resonances creates a “groove” that is the cause of a new unstable mode. Thus we now understand that the cause of spiral patterns in simulations is a recurrent cycle of groove modes. In other work, we have used Gaia DR2 data, converted to action-angle variables, to identify resonant scattering features in the Solar neighborhood that closely resemble those seen in the simulations, suggesting that the mechanism that causes spirals in simulations may also be at work in the Milky Way.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319007051
      Issue No: Vol. 14, No. S353 (2019)
  • Kinematical signatures of disc instabilities and secular evolution in the
           MUSE TIMER Survey
    • Authors: Dimitri A. Gadotti; Adrian Bittner, Jesus Falcón-Barroso, Jairo Méndez-Abreu, Monica Valluri, J. A. Sellwood
      Pages: 135 - 139
      Abstract: The MUSE TIMER Survey has obtained high signal and high spatial resolution integral-field spectroscopy data of the inner ~ 6×6 kpc of 21 nearby massive disc galaxies. This allows studies of the stellar kinematics of the central regions of massive disc galaxies that are unprecedented in spatial resolution. We confirm previous predictions from numerical and hydrodynamical simulations of the effects of bars and inner bars on stellar and gaseous kinematics, and also identify box/peanuts via kinematical signatures in mildly and moderately inclined galaxies, including a box/peanut in a face-on inner bar. In 20/21 galaxies we find inner discs and show that their properties are fully consistent with the bar-driven secular evolution picture for their formation. In addition, we show that these inner discs have, in the region where they dominate, larger rotational support than the main galaxy disc, and discuss how their stellar population properties can be used to estimate when in cosmic history the main bar formed. Our results are compared with photometric studies in the context of the nature of galaxy bulges and we show that inner discs are identified in image decompositions as photometric bulges with exponential profiles (i.e., Sérsic indices near unity).
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008585
      Issue No: Vol. 14, No. S353 (2019)
  • The sequence of spiral arm classes: Observational signatures of persistent
           spiral density waves in grand-design galaxies
    • Authors: A. Bittner; D. A. Gadotti, B. G. Elmegreen, E. Athanassoula, D. M. Elmegreen, A. Bosma, J. Muñoz-Mateos, Monica Valluri, J. A. Sellwood
      Pages: 140 - 143
      Abstract: We investigate how the properties of spiral arms relate to other fundamental galaxy properties. To this end, we use previously published measurements of those properties, and our own measurements of arm-interarm luminosity contrasts for a large sample of galaxies, using 3.6μm images from the Spitzer Survey of Stellar Structure in Galaxies. Flocculent galaxies are clearly distinguished from other spiral arm classes, especially by their lower stellar mass and surface density. Multi-armed and grand-design galaxies are similar in most of their fundamental parameters, excluding some bar properties and the bulge-to-total luminosity ratio. Based on these results, we discuss dense, classical bulges as a necessary condition for standing spiral wave modes in grand-design galaxies. We further find a strong correlation between bulge-to-total ratio and bar contrast, and a weaker correlation between arm and bar contrasts.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008160
      Issue No: Vol. 14, No. S353 (2019)
  • Dynamical regularities in rotating galaxies
    • Authors: Stacy McGaugh; Federico Lelli, Pengfei Li, Jim Schombert, Monica Valluri, J. A. Sellwood
      Pages: 144 - 151
      Abstract: Galaxies are observed to obey a strict set of dynamical scaling relations. We review these relations for rotationally supported disk galaxies spanning many decades in mass, surface brightness, and gas content. The behavior of these widely varied systems can be summarized with a handful of empirical laws connected by a common acceleration scale.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008172
      Issue No: Vol. 14, No. S353 (2019)
  • Evolution of disk galaxies in MOdified Gravity (MOG)
    • Authors: Neda Ghafourian; Mahmood Roshan, Monica Valluri, J. A. Sellwood
      Pages: 152 - 153
      Abstract: Evolution and the formation of bars in the galactic disks is studied in the context of Modified Gravity (MOG) by using N-body simulations. It is found that changing the value of free parameters of the model can effectively alter the strength of the bar and disk’s stability.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008810
      Issue No: Vol. 14, No. S353 (2019)
  • The puzzle of unbarred galaxies
    • Authors: Juntai Shen; Monica Valluri, J. A. Sellwood
      Pages: 154 - 154
      Abstract: Nearly two thirds of spiral galaxies are either strongly or weakly barred, yet a significant fraction of disc galaxies do not have a bar. Now we understand that there are at least three ways of making bars, i.e., bar instability, tidal interaction, and secular bar growth by orbit trapping of a seed bar. However, the reverse problem of avoiding bar formation in unbarred galaxies may be more challenging than we thought. It is shocking that we still do not understand how the bar instability is avoided in real galaxies such as M33, and this puzzle may be central to the outstanding issue of what determines the distribution of bar strengths in galaxies.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008822
      Issue No: Vol. 14, No. S353 (2019)
  • Secular evolution and pseudo-bulges
    • Authors: Francoise Combes; Monica Valluri, J. A. Sellwood
      Pages: 155 - 161
      Abstract: Through vertical resonances, bars can produce pseudo-bulges, within secular evolution. Bulges and pseudo-bulges have doubled their mass since z=1. The frequency of bulge-less galaxies at z=0 is difficult to explain, especially since clumpy galaxies at high z should create classical bulges in all galaxies. This issue is solved in modified gravity models. Bars and spirals in a galaxy disk, produce gravity torques that drive the gas to the center and fuel central star formation and nuclear activity. At 0.1-1kpc scale, observations of gravity torques show that only about one third of Seyfert galaxies experience molecular inflow and central fueling, while in most cases the gas is stalled in resonant rings. At 10-20pc scale, some galaxies have clearly revealed AGN fueling due to nuclear trailing spirals, influenced by the black hole potential. Thanks to ALMA, and angular resolution of up to 80mas, it is possible to reach the central black hole (BH) zone of influence, discover molecular tori, circum-nuclear disks misaligned with the galaxy, and the BH mass can be derived more directly from the kinematics.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319007397
      Issue No: Vol. 14, No. S353 (2019)
  • The face-on views of X-shaped “bulges” - boxy features in the
           central parts of bars
    • Authors: Panos A. Patsis; Monica Valluri, J. A. Sellwood
      Pages: 162 - 165
      Abstract: Boxiness associated with the morphology of the central parts of bars, is a feature usually encountered in the edge-on profiles of galaxies, or galactic models. However, there are cases where “boxy” isophotes are observed also in the central parts of nearly face-on bars. I summarize here some dynamical mechanisms that support boxy orbits in the central bar regions on the equatorial plane of the disks, or orbits with boxy projections on it. Such orbits could describe the dynamics of face – on boxy “bulges”.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008226
      Issue No: Vol. 14, No. S353 (2019)
  • The evolution of bulges of galaxies in minor fly-by interactions
    • Authors: Ankit Kumar; Mousumi Das, Sandeep Kumar Kataria, Monica Valluri, J. A. Sellwood
      Pages: 166 - 167
      Abstract: We investigate the minor interactions of two disk galaxies with mass ratio of 10:1 in fly-by encounters that do not lead to the merging of the galaxies. In our N-body simulations, we vary only the pericenter distances to see the effect of the fly-by on the bulge of the major galaxy over the course of the trajectory. At different time steps of the evolution, we did two-dimensional fittings of disk, bulge and bar to trace the variation in the sersic index of the bulge. Our results suggest that galaxy bulges can become boxy/disky through flyby interactions of galaxies.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008251
      Issue No: Vol. 14, No. S353 (2019)
  • The long-lived inner bar of NGC 1291
    • Authors: Jairo Méndez-Abreu; Adriana de Lorenzo-Cáceres, Monica Valluri, J. A. Sellwood
      Pages: 168 - 171
      Abstract: The question whether stellar bars are either transitory features or long-lived structures is still matter of debate. This problem is more acute for double-barred systems where even the formation of the inner bar remains a challenge for numerical studies. We present a thorough study of the central structures of the double-barred galaxy NGC 1291. We used a two-dimensional multi-component photometric decomposition performed on the 3.6 μm images from S4 G, combined with both stellar kinematics and stellar population analysis carried out using integral field data from the MUSE TIMER project. We report on the discovery of the first Box-Peanut (B/P) structure in an inner bar detected in the face-on galaxy NGC 1291. The B/P structure is detected as bi-symmetric minima of the h4 moment of the line-of-sight velocity distribution along the major axis of the inner bar, as expected from numerical simulations. Our observations demonstrate that inner bars (similarly as outer bars) can suffer buckling instabilities, thus suggesting they can survive a long time after bar formation. The analysis of the star formation history for the structural components shaping the central regions of NGC 1291 also constrains the epoch of dynamical assembly of the inner bar, which took place >6.5 Gyr ago for NGC 1291. Our results imply that the inner bar of NGC 1291 is a long-lived structure.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319009657
      Issue No: Vol. 14, No. S353 (2019)
  • A MUSE study of the fast bar in the weakly-interacting galaxy NGC 4264
    • Authors: Virginia Cuomo; Enrico Maria Corsini, Alfonso J. L. Aguerri, Victor P. Debattista, Monica Valluri, J. A. Sellwood
      Pages: 172 - 175
      Abstract: We present surface photometry and stellar kinematics of NGC 4264, a lenticular galaxy in the region of the Virgo Cluster undergoing a tidal interaction with its neighbour, NGC 4261. We measured the bar radius and strength from SDSS imaging and the bar pattern speed from MUSE integral-field spectroscopy. We find that NGC 4264 hosts a strong and large bar, which is rotating fast. The accurate measurement of the bar rotation rate allows us to exclude that the formation of the bar was triggered by the ongoing interaction.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S174392131900927X
      Issue No: Vol. 14, No. S353 (2019)
  • Schwarzschild modeling of barred galaxies
    • Authors: Eugene Vasiliev; Monica Valluri, Monica Valluri, J. A. Sellwood
      Pages: 176 - 183
      Abstract: We review the Schwarzschild orbit-superposition approach and present a new implementation of this method, which can deal with a large class of systems, including rotating barred disk galaxies. We discuss two conceptual problems in this field: the intrinsic degeneracy of determining the potential from line-of-sight kinematics, and the non-uniqueness of deprojection and related biases in potential inference, especially acute for triaxial bars. When applied to mock datasets with known 3d shape, our method correctly recovers the pattern speed and other potential parameters. However, more work is needed to systematically address these two problems for real observational datasets.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008706
      Issue No: Vol. 14, No. S353 (2019)
  • Can bars erode cuspy halos'
    • Authors: Sandeep Kumar Kataria; Mousumi Das, Stacy Mcgaugh, Monica Valluri, J. A. Sellwood
      Pages: 184 - 185
      Abstract: One of the major and widely known small scale problem with the Lambda CDM model of cosmology is the “core-cusp” problem. In this study we investigate whether this problem can be resolved using bar instabilities. We see that all the initial bars are thin (b/a < 0.3) in our simulations and the bar becomes thick ( b /a > 0.3) faster in the high resolution simulations. By increasing the resolution, we mean a larger number of disk particles. The thicker bars in the high resolution simulations transfer less angular momentum to the halo. Hence, we find that in the high resolution simulations it takes around 7 Gyr for the bar to remove inner dark matter cusp which is too long to be meaningful in galaxy evolution timescales. Physically, the reason is that as the resolution increases, the bar buckles faster and becomes thicker much earlier on.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008743
      Issue No: Vol. 14, No. S353 (2019)
  • Coevolution (or not) of supermassive black holes and host galaxies: Black
           hole scaling relations are not biased by selection effects
    • Authors: John Kormendy; Monica Valluri, J. A. Sellwood
      Pages: 186 - 198
      Abstract: The oral version of this paper summarized Kormendy & Ho 2013, ARA&A, 51, 511. However, earlier speakers at this Symposium worried that selection effects bias the derivation of black hole scaling relations. I therefore added – and this proceedings paper emphasizes – a discussion of why we can be confident that selection effects do not bias the observed correlations between BH mass M• and the luminosity, stellar mass, and velocity dispersion of host ellipticals and classical bulges. These are the only galaxy components that show tight BH-host correlations. The scatter plots of M• with host properties for pseudobulges and disks are upper envelopes of scatter that does extend to lower BH masses. BH correlations are most consistent with a picture in which BHs coevolve only with classical bulges and ellipticals. Four physical regimes of coevolution (or not) are suggested by Kormendy & Ho 2013 and are summarized here.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008500
      Issue No: Vol. 14, No. S353 (2019)
  • Testing the robustness of black hole mass measurements with ALMA and MUSE
    • Authors: Sabine Thater; Davor Krajnović, Dieu D. Nguyen, Satoru Iguchi, Peter M. Weilbacher, Monica Valluri, J. A. Sellwood
      Pages: 199 - 202
      Abstract: We present our ongoing work of using two independent tracers to estimate the supermassive black hole mass in the nearby early-type galaxy NGC 6958; namely integrated stellar and molecular gas kinematics. We used data from the Atacama Large Millimeter/submillimeter Array (ALMA), and the adaptive-optics assisted Multi-Unit Spectroscopic Explorer (MUSE) and constructed state-of-the-art dynamical models. The different methods provide black hole masses of (2.89±2.05)×108M⊙ from stellar kinematics and (1.35±0.09)×108M⊙ from molecular gas kinematics which are consistent within their 3σ uncertainties. Compared to recent MBH - σe scaling relations, we derive a slightly over-massive black hole. Our results also confirm previous findings that gas-based methods tend to provide lower black hole masses than stellar-based methods. More black hole mass measurements and an extensive analysis of the method-dependent systematics are needed in the future to understand this noticeable discrepancy.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008445
      Issue No: Vol. 14, No. S353 (2019)
  • The dynamics in the inner kpc of the lenticular galaxy IC 676
    • Authors: Zhimin Zhou; Monica Valluri, J. A. Sellwood
      Pages: 203 - 204
      Abstract: Lenticular galaxies play an important part in the morphology classes. Their detailed study provides important information with regard to the formation and evolution of the different morphological types of galaxies. Here we investigated a barred lenticular galaxy IC 676, which has double nuclei in its inner kpc region. Based on the integral-field spectroscopy data, we presented the dynamics in the central region of IC 676, and tried to explore the nature and formation of its double nuclei.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S174392131900810X
      Issue No: Vol. 14, No. S353 (2019)
  • Twelve years of Galaxy Zoo
    • Authors: Karen L. Masters; Monica Valluri, J. A. Sellwood
      Pages: 205 - 212
      Abstract: The Galaxy Zoo project has provided quantitative visual morphologies for over a million galaxies, and has been part of a reinvigoration of interest in the morphologies of galaxies and what they reveal about galaxy evolution. Morphological information collected by GZ has shown itself to be a powerful tool for studying galaxy evolution, and GZ continues to collect classifications - currently serving imaging from DECaLS in its main site, and running a variety of related projects hosted by the Zooniverse; the citizen science platform which came out of the early success of GZ. I highlight some of the results from the last twelve years, with a particular emphasis on linking morphology and dynamics, look forward to future projects in the GZ family, and provide a quick start guide for how you can easily make use of citizen science techniques to analysis your own large and complex data sets.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008615
      Issue No: Vol. 14, No. S353 (2019)
  • Key dynamical results from the SAMI Galaxy Survey
    • Authors: Jesse van de Sande; Joss Bland-Hawthorn, Dilyar Barat, Sarah Brough, Julia J. Bryant, Scott M. Croom, Luca Cortese, Monica Valluri, J. A. Sellwood
      Pages: 213 - 221
      Abstract: We present an overview of recent key results from the SAMI Galaxy Survey on the build-up of mass and angular momentum in galaxies across morphology and environment. The SAMI Galaxy survey is a multi-object integral field spectroscopic survey and provides a wealth of spatially-resolved, two-dimensional stellar and gas measurements for galaxies of all morphological types, with high-precision due the stable spectral resolution of the AAOmega spectrograph. The sample size of ~3000 galaxies allows for dividing the sample in bins of stellar mass, environment, and star-formation or morphology, whilst maintaining a statistical significant number of galaxies in each bin. By combining imaging, spatially resolved dynamics, and stellar population measurements, our result demonstrate the power of utilising integral field spectroscopy on a large sample of galaxies to further our understanding of physical processes involved in the build-up of stellar mass and angular momentum in galaxies.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S174392131900913X
      Issue No: Vol. 14, No. S353 (2019)
  • The intricate link between galaxy dynamics and intrinsic shape (or why
           so-called prolate rotation is a misnomer)
    • Authors: Caroline Foster; Robert Bassett, Monica Valluri, J. A. Sellwood
      Pages: 222 - 225
      Abstract: Many recent integral field spectroscopy (IFS) survey teams have used stellar kinematic maps combined with imaging to statistically infer the underlying distributions of galaxy intrinsic shapes. With now several IFS samples at our disposal, the method, which was originally proposed by M. Franx and collaborators in 1991, is gaining in popularity, having been so far applied to ATLAS3D, SAMI, MANGA and MASSIVE. We present results showing that a commonly assumed relationship between dynamical and intrinsic shape alignment does not hold in Illustris, affecting our ability to recover accurate intrinsic shape distributions. A further implication is that so-called “prolate rotation”, where the bulk of stars in prolate galaxies are thought to rotate around the projected major axis, is a misnomer.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319007944
      Issue No: Vol. 14, No. S353 (2019)
  • Properties of barred galaxies in the MaNGA galaxy survey
    • Authors: Amelia Fraser-McKelvie; Michael Merrifield, Alfonso Aragón-Salamanca, Karen Masters, Monica Valluri, J. A. Sellwood
      Pages: 226 - 230
      Abstract: We present the initial results of a census of 684 barred galaxies in the MaNGA galaxy survey. This large sample contains galaxies with a wide range of physical properties, and we attempt to link bar properties to key observables for the whole galaxy. We find the length of the bar, when normalised for galaxy size, is correlated with the distance of the galaxy from the star formation main sequence, with more passive galaxies hosting larger-scale bars. Ionised gas is observed along the bars of low-mass galaxies only, and these galaxies are generally star-forming and host short bars. Higher-mass galaxies do not contain Hα emission along their bars, however, but are more likely to host rings or Hα at the centre and ends of the bar. Our results suggest that different physical processes are at play in the formation and evolution of bars in low- and high-mass galaxies.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008081
      Issue No: Vol. 14, No. S353 (2019)
  • Spotting a counter-rotating galaxy
    • Authors: Michela Rubino; Alessandro Pizzella, Lorenzo Morelli, Monica Valluri, J. A. Sellwood
      Pages: 231 - 232
      Abstract: The presence of counter-rotating (CR) components in galaxies is not that rare but their origin is still unclear. Important clues to the formation and evolution of CR galaxies are provided by galaxy kinematics, such as the mass distribution and the shape of the gravitational potential. In order to better understand the origin and incidence of CR galaxies, we aim at modeling CR stellar disks, as they would be observed with Integral Field Units (IFU) instruments, and measuring the kinematics of these peculiar astrophysical objects to reveal the CR signatures. In the bi-dimensional maps of analysed models, the double sigma signature is the best diagnostic to spot the presence of a CR disk component.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008676
      Issue No: Vol. 14, No. S353 (2019)
  • Elliptical galaxies/stellar halos connection
    • Authors: Magda Arnaboldi; Claudia Pulsoni, Ortwin Gerhard, Monica Valluri, J. A. Sellwood
      Pages: 233 - 238
      Abstract: Cosmological simulations predict that early-type galaxies (ETGs) are the results of extended mass accretion histories. The latter are characterized by different numbers of mergers, mergers’ mass ratios and gas fractions, and timing. Depending on the sequence and nature of these mergers that follow the first phase of the in-situ star formation, these accretion histories may lead to ETGs that have low or high mass halos, and that rotate fast or slow. Since the stellar halos maintain the fossil records of the events that led to their formation, a discontinuity may be in place between the inner regions of ETGs and their outer halos, because the time required for the halos’ stars to exchange their energies and momenta is very long compared with the age of these systems. Exquisite deep photometry and extended spectroscopy for significant samples of ETGs are then used to quantify the occurrence and significance of such a transition in the galaxies’ structural and kinematical parameters. Once this transition radius is measured, its dependency with the effective radius of the galaxies’ light distribution and total stellar masses can be investigated. Such correlations can then be compared with the predictions of accreted, i.e. ex-situ vs. in-situ components from cosmological simulations to validate such models.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319009712
      Issue No: Vol. 14, No. S353 (2019)
  • Dark matter distribution and dynamics of dwarf spheroidal galaxies
    • Authors: Ewa L. Łokas; Monica Valluri, J. A. Sellwood
      Pages: 239 - 245
      Abstract: I review the current status of dynamical modelling of dwarf spheroidal galaxies focusing on estimates of their dark matter content. Starting with the simplest methods using the velocity dispersion profiles I discuss the inherent issues of mass-anisotropy degeneracy and contamination by unbound stars. I then move on to methods of increasing complexity, aiming to break the degeneracy, up to recent applications of the Schwarzschild orbit superposition method. The dynamical modelling is placed in the context of possible scenarios for the formation of dwarf spheroidal galaxies, including the tidal stirring model and mergers of dwarf galaxies. The two scenarios are illustrated with examples from simulations: a comparison between the tidal evolution of dwarfs with cuspy and cored dark matter profiles and the formation of a dwarf spheroidal with prolate rotation.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319007956
      Issue No: Vol. 14, No. S353 (2019)
  • Linear stability of stellar rotating spheres
    • Authors: Simon Rozier; Jean-Baptiste Fouvry, Philip G. Breen, Anna Lisa Varri, Christophe Pichon, Douglas C. Heggie, Monica Valluri, J. A. Sellwood
      Pages: 246 - 247
      Abstract: Recent observations of globular clusters encourage to revise some aspects of the traditional paradigm, in which they were considered to be isotropic in velocity space and non-rotating. However, the theory of collisionless spheroids with some kinematic richness has seldom been studied. We present here a further step in this direction, owing to new results regarding the linear stability of rotating Plummer spheres, with varying anisotropy in velocity space and total amount of angular momentum. We extend the well-known radial orbit instability to rotating systems, and discover a new regime of instability in fast rotating, tangentially anisotropic systems.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008184
      Issue No: Vol. 14, No. S353 (2019)
  • Galactic dynamics and DM profile of NGC1380 with ALMA and VLT/MUSE
    • Authors: Takafumi Tsukui; Satoru Iguchi, Kyoko Onishi, Monica Valluri, J. A. Sellwood
      Pages: 248 - 252
      Abstract: In order to understand the interaction between dark matter and baryonic matter in the galaxy evolution history, it is fundamental to constrain dark matter (DM) distribution in galaxies. However, it is difficult to constrain DM profile in the central region of early type galaxy because of the lack of extended neutral hydrogen gas and the degeneracy between dynamical stellar M/L and DM profile. To resolve this difficulty, we conducted combined analysis of ALMA cold molecular gas kinematics and MUSE stellar kinematics of early type fast rotator galaxy NGC1380. In addition, we used HST image to trace the stellar luminosity distribution. With the help of high resolution of ALMA image and large field of view of MUSE, we derived the central BH mass, stellar bulge, disk and DM profile.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008767
      Issue No: Vol. 14, No. S353 (2019)
  • Mapping the dark matter of NGC 2974: Combination of stellar & cold gas
    • Authors: M. Yang; L. Zhu, A. Weijmans, G. van de Ven, N. F. Boardman, R. Morganti, T. A. Oosterloo, Monica Valluri, J. A. Sellwood
      Pages: 253 - 254
      Abstract: We present a new method to combine cold gas kinematics with the stellar kinematics modelled with the Schwarzschild orbit-superposition technique, and its application to the lenticular galaxy NGC 2974. The combination of stellar and cold gas kinematics significantly improves the constraints on the measured dark matter profile: assuming a generalised NFW halo profile, we find a cuspy inner halo slope for NGC 2974.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008287
      Issue No: Vol. 14, No. S353 (2019)
  • Stellar and dynamical masses of brightest cluster galaxies
    • Authors: S. I. Loubser; Monica Valluri, J. A. Sellwood
      Pages: 255 - 256
      Abstract: We investigate the stellar and dynamical mass profiles of 32 brightest cluster galaxies (BCGs, MK = −25.7 to −27.8 mag) in massive clusters (0.05 < z < 0.30), and in particular the rising velocity dispersion profiles of 23 of these BCGs found in Loubser et al. (2018). We make comprehensive measurements of the Gauss-Hermite higher order velocity moments h3 and h4, and find positive central values for h4 for all the BCGs. We model the stellar and dynamical mass profiles of 25 of the BCGs using the Multi-Gaussian Expansion (MGE) and Jeans Anisotropic Method (JAM) for an axisymmetric case, deriving the stellar mass-to-light ratio (ϒ*DYN), and anisotropy (βz). We further explicitly add a dark matter halo mass component (MDM within r200) which we constrain from weak lensing results. In this proceedings, we summarise the study and show an example of the results.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008123
      Issue No: Vol. 14, No. S353 (2019)
  • Dynamical modelling of brightest cluster galaxies: Constraints on the IMF
    • Authors: S. I. Loubser; Monica Valluri, J. A. Sellwood
      Pages: 257 - 258
      Abstract: We study the stellar and dynamical masses, as well as the stellar populations, of brightest cluster galaxies (BCGs) located in 32 massive clusters, and for a sub-sample of these use the results to place constraints on the Initial Mass Function (IMF). We measure the spatially-resolved stellar population properties of the BCGs, such as recent star formation episodes, and use it to predict their stellar mass-to-light ratios (ϒ*POP). We find that ∼60 per cent of the BCGs have constant ϒ*POP over the radial range (
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008093
      Issue No: Vol. 14, No. S353 (2019)
  • No preferred alignments of angular momentum vectors of galaxies in the
           SDSS supercluster S[202-001+0084]
    • Authors: Janak R. Malla; Walter Saurer, Binil Aryal, Monica Valluri, J. A. Sellwood
      Pages: 259 - 261
      Abstract: We present spatial orientation of angular momentum vectors of 3038 galaxies in the SDSS supercluster S[202-002+0084] having mean redshift 0.084. The selection effects in the database are removed using random simulation method. The observed distributions of angular momentum vectors of galaxies are compared with expected theoretical distribution using chi-square, auto-correlation and Fourier tests. No preferred alignments of angular momentum vectors of galaxies are noticed in the supercluster S[202-001+0084], supporting hierarchy model.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008858
      Issue No: Vol. 14, No. S353 (2019)
  • Kinematic asymmetry of galaxy pairs
    • Authors: Shuai Feng; Shi-Yin Shen, Fang-Ting Yuan, Monica Valluri, J. A. Sellwood
      Pages: 262 - 263
      Abstract: The interaction between galaxies is believed to be the main origin of the peculiarities of galaxies. It can disturb not only the morphology but also the kinematics of galaxies. These disturbed and asymmetric features are the indicators of galaxy interaction. We study the velocity field of ionized gas in galaxy pairs based on MaNGA survey. Using the kinemetry package, we fit the velocity field and quantify the degree of kinematic asymmetry. We find that the fraction of high kinematic asymmetry is much higher for galaxy pairs with dp⩽30h−1kpc. Moreover, compared to a control sample of single galaxies, we find that the star formation rate is enhanced in paired galaxies with high kinematic asymmetry. For paired galaxies with low kinematic asymmetry, no significant SFR enhancement has been found. The galaxy pairs with high kinematic asymmetry are more likely to be real interacting galaxies rather than projected pairs.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008305
      Issue No: Vol. 14, No. S353 (2019)
  • Gas dynamics and star formation in “isolated” and interacting galaxies
           using FP observations
    • Authors: Isaura Fuentes-Carrera; Nelli Cárdenas-Martínez, Martín Nava-Callejas, Margarita Rosado, Monica Valluri, J. A. Sellwood
      Pages: 264 - 265
      Abstract: We present scanning Fabry-Perot observations of different types of star-forming galaxies from apparently isolated LIRGs to equal mass interacting galaxies. We analyze the ionized gas kinematics, its relation with the morphology of each system and the location of SF regions for different systems.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008238
      Issue No: Vol. 14, No. S353 (2019)
  • Accreted Globular Clusters in external galaxies: Why adaptive dynamics is
           not the solution
    • Authors: Sophia Lilleengen; Wilma Trick, Glenn van de Ven, Monica Valluri, J. A. Sellwood
      Pages: 266 - 270
      Abstract: Many astrophysical and galaxy-scale cosmological problems require a well determined gravitational potential which is often modeled by observers under strong assumptions. Globular clusters (GCs) surrounding galaxies can be used as dynamical tracers of the luminous and dark matter distribution at large (kpc) scales. A natural assumption for modeling the gravitational potential is that GCs accreted in the same dwarf galaxy merger event move at the present time on similar orbits in the host galaxy and should therefore have similar actions. We investigate this idea in one realistic Milky Way like galaxy of the cosmological N-body simulation suite Auriga. We show how the actions of accreted stellar particles in the simulation evolve and that minimizing the standard deviation of GCs in action space, however, cannot constrain the true potential. This approach known as ‘adaptive dynamics’ does therefore not work for accreted GCs.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008196
      Issue No: Vol. 14, No. S353 (2019)
  • Structure and dynamics of high-z galaxies
    • Authors: Stijn Wuyts; Natascha M. Förster Schreiber, Monica Valluri, J. A. Sellwood
      Pages: 271 - 278
      Abstract: HST and integral-field spectroscopic observations of star-forming galaxies at cosmic noon provide a view on the spatial distribution of stars, gas and dust, and probe gaseous motions revealing the central gravitational potential and local feedback processes at play. In this paper, we review recent insights gained from such observations, with an emphasis on results obtained through near-infrared imaging spectroscopy. Their context and implications are documented more fully in a forthcoming review article by Förster Schreiber & Wuyts (in prep).
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319009293
      Issue No: Vol. 14, No. S353 (2019)
  • A full pipeline for modelling low surface brightness galaxies
    • Authors: Marius Peper; Boudewijn F. Roukema, Krzysztof Bolejko, Monica Valluri, J. A. Sellwood
      Pages: 279 - 280
      Abstract: Cosmological simulations are a powerful tool to test various cosmological and galaxy formation scenarios. The discovery of low surface brightness objects has been a challenge for both of these fields. Our work aims to create a fully reproducible pipeline to generate a realistic dark matter halo catalog with corresponding information on galaxy formation and evolution.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008548
      Issue No: Vol. 14, No. S353 (2019)
  • Effect of the gas percentage on the thickness of the galactic discs during
           minor mergers using hydrodynamical simulations
    • Authors: Swetha Thakkalapally; Priya Hasan, S. N. Hasan, Monica Valluri, J. A. Sellwood
      Pages: 281 - 283
      Abstract: We study the minor mergers of galaxies using simulations. For this we use GADGET2 code. We present results of simulations of minor mergers of disc galaxies of mass ratio 1:10. These simulations consist of collisionless as well as hydrodynamical runs including a gaseous component in the galactic disc of primary galaxy. Our goal is to establish the characteristics of discs obtained after the merger.We observe that the primary galaxy discs are not destroyed after the merger. We take different initial conditions for the primary galaxy varying the gas percentage in disc from 0–40 percentage and study the thickness of the disc after the merger. We generally observe that the thickness of the disc increases after the merger for any gas percentage. We also observe that as the gas percentage increases in the disc of initial primary galaxy, the increase in the thickness keeps decreasing.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S174392131900824X
      Issue No: Vol. 14, No. S353 (2019)
  • The GIST pipeline: A multi-purpose tool for the analysis and visualisation
           of (integral-field) spectroscopic data
    • Authors: A. Bittner; J. Falcón-Barroso, B. Nedelchev, A. Dorta, D. A. Gadotti, M. Sarzi, A. Molaeinezhad, E. Iodice, D. Rosado-Belza, A. de Lorenzo-Cáceres, F. Fragkoudi, P. M. Galán-de Anta, B. Husemann, J. Méndez-Abreu, J. Neumann, F. Pinna, M. Querejeta, P. Sánchez-Blázquez, M. K. Seidel, Monica Valluri, J. A. Sellwood
      Pages: 284 - 285
      Abstract: We introduce the Galaxy IFU Spectroscopy Tool (GIST), a convenient, all-in-one and multi-purpose tool for the analysis and visualisation of already reduced (integral-field) spectroscopic data. In particular, the pipeline performs all steps from read-in and preparation of data to its scientific analysis and visualisation in publication-quality plots. The code measures stellar kinematics and non-parametric star formation histories using the pPXF routine (Cappellari & Emsellem 2004; Cappellari 2017), performs an emission-line analysis with the GandALF procedure (Sarzi et al. 2006; Falcón-Barroso et al. 2006), and determines absorption line-strength indices and their corresponding single stellar population equivalent population properties (Kuntschner et al.2006; Martín-Navarro et al. 2018). The dedicated visualisation routine Mapviewer facilitates the access of all data products in a sophisticated graphical user interface with fully interactive plots.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319008652
      Issue No: Vol. 14, No. S353 (2019)
  • The demographics of central massive black holes in low-mass early-type
    • Authors: Dieu D. Nguyen; Monica Valluri, J. A. Sellwood
      Pages: 286 - 288
      Abstract: The existence intermediate mass black holes (IMBH, MBH ≲ 106M⊙) at the centers low-mass galaxies with stellar masses between (1–10)×10M⊙ are key to constraining the origin of black hole (BH) seeds and understanding the physics deriving the co-evolution of central BHs and their host galaxies. However, finding and weighing IMBH is challenging. Here, we present the first observational evidence for such IMBHs at the centers of the five nearest early-type galaxies (D < 3.5 Mpc, ETGs) revealed by adaptive optics kinematics from Gemini and VLT and high-resolution HST spectroscopy. We find that all five galaxies appear to host IMBHs with four of the five having masses below 1 million M⊙ and the lowest mass BH being only ∼7,000 M⊙. This work provides a first glimpse of the demographics of IMBHs in this galaxy mass range and at velocity dispersions < 70 km/s, and thus provides an important extension to the bulge mass and galaxy dispersion scaling relations. The ubiquity of central BHs in these galaxies provides a unique constraint on BH seed formation scenarios, favoring a formation mechanism that produces an abundance of low-mass seed BHs.
      PubDate: 2019-06-01T00:00:00.000Z
      DOI: 10.1017/S1743921319009001
      Issue No: Vol. 14, No. S353 (2019)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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