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Publisher: Oxford University Press   (Total: 396 journals)

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Showing 1 - 200 of 396 Journals sorted alphabetically
ACS Symposium Series     Full-text available via subscription   (SJR: 0.189, CiteScore: 0)
Acta Biochimica et Biophysica Sinica     Hybrid Journal   (Followers: 5, SJR: 0.79, CiteScore: 2)
Adaptation     Hybrid Journal   (Followers: 8, SJR: 0.143, CiteScore: 0)
Advances in Nutrition     Hybrid Journal   (Followers: 44, SJR: 2.196, CiteScore: 5)
Aesthetic Surgery J.     Hybrid Journal   (Followers: 6, SJR: 1.434, CiteScore: 1)
African Affairs     Hybrid Journal   (Followers: 63, SJR: 1.869, CiteScore: 2)
Age and Ageing     Hybrid Journal   (Followers: 88, SJR: 1.989, CiteScore: 4)
Alcohol and Alcoholism     Hybrid Journal   (Followers: 18, SJR: 1.376, CiteScore: 3)
American Entomologist     Full-text available via subscription   (Followers: 6)
American Historical Review     Hybrid Journal   (Followers: 147, SJR: 0.467, CiteScore: 1)
American J. of Agricultural Economics     Hybrid Journal   (Followers: 40, SJR: 2.113, CiteScore: 3)
American J. of Clinical Nutrition     Hybrid Journal   (Followers: 144, SJR: 3.438, CiteScore: 6)
American J. of Epidemiology     Hybrid Journal   (Followers: 168, SJR: 2.713, CiteScore: 3)
American J. of Hypertension     Hybrid Journal   (Followers: 25, SJR: 1.322, CiteScore: 3)
American J. of Jurisprudence     Hybrid Journal   (Followers: 18, SJR: 0.281, CiteScore: 1)
American J. of Legal History     Full-text available via subscription   (Followers: 8, SJR: 0.116, CiteScore: 0)
American Law and Economics Review     Hybrid Journal   (Followers: 27, SJR: 1.053, CiteScore: 1)
American Literary History     Hybrid Journal   (Followers: 15, SJR: 0.391, CiteScore: 0)
Analysis     Hybrid Journal   (Followers: 21, SJR: 1.038, CiteScore: 1)
Animal Frontiers     Hybrid Journal  
Annals of Behavioral Medicine     Hybrid Journal   (Followers: 14, SJR: 1.423, CiteScore: 3)
Annals of Botany     Hybrid Journal   (Followers: 35, SJR: 1.721, CiteScore: 4)
Annals of Oncology     Hybrid Journal   (Followers: 42, SJR: 5.599, CiteScore: 9)
Annals of the Entomological Society of America     Full-text available via subscription   (Followers: 9, SJR: 0.722, CiteScore: 1)
Annals of Work Exposures and Health     Hybrid Journal   (Followers: 33, SJR: 0.728, CiteScore: 2)
AoB Plants     Open Access   (Followers: 4, SJR: 1.28, CiteScore: 3)
Applied Economic Perspectives and Policy     Hybrid Journal   (Followers: 17, SJR: 0.858, CiteScore: 2)
Applied Linguistics     Hybrid Journal   (Followers: 56, SJR: 2.987, CiteScore: 3)
Applied Mathematics Research eXpress     Hybrid Journal   (Followers: 1, SJR: 1.241, CiteScore: 1)
Arbitration Intl.     Full-text available via subscription   (Followers: 20)
Arbitration Law Reports and Review     Hybrid Journal   (Followers: 14)
Archives of Clinical Neuropsychology     Hybrid Journal   (Followers: 30, SJR: 0.731, CiteScore: 2)
Aristotelian Society Supplementary Volume     Hybrid Journal   (Followers: 3)
Arthropod Management Tests     Hybrid Journal   (Followers: 2)
Astronomy & Geophysics     Hybrid Journal   (Followers: 42, SJR: 0.146, CiteScore: 0)
Behavioral Ecology     Hybrid Journal   (Followers: 52, SJR: 1.871, CiteScore: 3)
Bioinformatics     Hybrid Journal   (Followers: 294, SJR: 6.14, CiteScore: 8)
Biology Methods and Protocols     Hybrid Journal  
Biology of Reproduction     Full-text available via subscription   (Followers: 10, SJR: 1.446, CiteScore: 3)
Biometrika     Hybrid Journal   (Followers: 20, SJR: 3.485, CiteScore: 2)
BioScience     Hybrid Journal   (Followers: 30, SJR: 2.754, CiteScore: 4)
Bioscience Horizons : The National Undergraduate Research J.     Open Access   (Followers: 1, SJR: 0.146, CiteScore: 0)
Biostatistics     Hybrid Journal   (Followers: 17, SJR: 1.553, CiteScore: 2)
BJA : British J. of Anaesthesia     Hybrid Journal   (Followers: 161, SJR: 2.115, CiteScore: 3)
BJA Education     Hybrid Journal   (Followers: 64)
Brain     Hybrid Journal   (Followers: 67, SJR: 5.858, CiteScore: 7)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 47, SJR: 2.505, CiteScore: 5)
Briefings in Functional Genomics     Hybrid Journal   (Followers: 3, SJR: 2.15, CiteScore: 3)
British J. for the Philosophy of Science     Hybrid Journal   (Followers: 34, SJR: 2.161, CiteScore: 2)
British J. of Aesthetics     Hybrid Journal   (Followers: 26, SJR: 0.508, CiteScore: 1)
British J. of Criminology     Hybrid Journal   (Followers: 582, SJR: 1.828, CiteScore: 3)
British J. of Social Work     Hybrid Journal   (Followers: 87, SJR: 1.019, CiteScore: 2)
British Medical Bulletin     Hybrid Journal   (Followers: 7, SJR: 1.355, CiteScore: 3)
British Yearbook of Intl. Law     Hybrid Journal   (Followers: 31)
Bulletin of the London Mathematical Society     Hybrid Journal   (Followers: 4, SJR: 1.376, CiteScore: 1)
Cambridge J. of Economics     Hybrid Journal   (Followers: 61, SJR: 0.764, CiteScore: 2)
Cambridge J. of Regions, Economy and Society     Hybrid Journal   (Followers: 10, SJR: 2.438, CiteScore: 4)
Cambridge Quarterly     Hybrid Journal   (Followers: 9, SJR: 0.104, CiteScore: 0)
Capital Markets Law J.     Hybrid Journal   (Followers: 2, SJR: 0.222, CiteScore: 0)
Carcinogenesis     Hybrid Journal   (Followers: 2, SJR: 2.135, CiteScore: 5)
Cardiovascular Research     Hybrid Journal   (Followers: 14, SJR: 3.002, CiteScore: 5)
Cerebral Cortex     Hybrid Journal   (Followers: 45, SJR: 3.892, CiteScore: 6)
CESifo Economic Studies     Hybrid Journal   (Followers: 17, SJR: 0.483, CiteScore: 1)
Chemical Senses     Hybrid Journal   (Followers: 1, SJR: 1.42, CiteScore: 3)
Children and Schools     Hybrid Journal   (Followers: 5, SJR: 0.246, CiteScore: 0)
Chinese J. of Comparative Law     Hybrid Journal   (Followers: 4, SJR: 0.412, CiteScore: 0)
Chinese J. of Intl. Law     Hybrid Journal   (Followers: 22, SJR: 0.329, CiteScore: 0)
Chinese J. of Intl. Politics     Hybrid Journal   (Followers: 9, SJR: 1.392, CiteScore: 2)
Christian Bioethics: Non-Ecumenical Studies in Medical Morality     Hybrid Journal   (Followers: 10, SJR: 0.183, CiteScore: 0)
Classical Receptions J.     Hybrid Journal   (Followers: 25, SJR: 0.123, CiteScore: 0)
Clean Energy     Open Access   (Followers: 1)
Clinical Infectious Diseases     Hybrid Journal   (Followers: 64, SJR: 5.051, CiteScore: 5)
Clinical Kidney J.     Open Access   (Followers: 3, SJR: 1.163, CiteScore: 2)
Communication Theory     Hybrid Journal   (Followers: 21, SJR: 2.424, CiteScore: 3)
Communication, Culture & Critique     Hybrid Journal   (Followers: 26, SJR: 0.222, CiteScore: 1)
Community Development J.     Hybrid Journal   (Followers: 27, SJR: 0.268, CiteScore: 1)
Computer J.     Hybrid Journal   (Followers: 9, SJR: 0.319, CiteScore: 1)
Conservation Physiology     Open Access   (Followers: 2, SJR: 1.818, CiteScore: 3)
Contemporary Women's Writing     Hybrid Journal   (Followers: 9, SJR: 0.121, CiteScore: 0)
Contributions to Political Economy     Hybrid Journal   (Followers: 5, SJR: 0.906, CiteScore: 1)
Critical Values     Full-text available via subscription  
Current Developments in Nutrition     Open Access  
Current Legal Problems     Hybrid Journal   (Followers: 27)
Current Zoology     Full-text available via subscription   (Followers: 2, SJR: 1.164, CiteScore: 2)
Database : The J. of Biological Databases and Curation     Open Access   (Followers: 8, SJR: 1.791, CiteScore: 3)
Digital Scholarship in the Humanities     Hybrid Journal   (Followers: 13, SJR: 0.259, CiteScore: 1)
Diplomatic History     Hybrid Journal   (Followers: 20, SJR: 0.45, CiteScore: 1)
DNA Research     Open Access   (Followers: 5, SJR: 2.866, CiteScore: 6)
Dynamics and Statistics of the Climate System     Open Access   (Followers: 3)
Early Music     Hybrid Journal   (Followers: 15, SJR: 0.139, CiteScore: 0)
Economic Policy     Hybrid Journal   (Followers: 39, SJR: 3.584, CiteScore: 3)
ELT J.     Hybrid Journal   (Followers: 24, SJR: 0.942, CiteScore: 1)
English Historical Review     Hybrid Journal   (Followers: 51, SJR: 0.612, CiteScore: 1)
English: J. of the English Association     Hybrid Journal   (Followers: 14, SJR: 0.1, CiteScore: 0)
Environmental Entomology     Full-text available via subscription   (Followers: 11, SJR: 0.818, CiteScore: 2)
Environmental Epigenetics     Open Access   (Followers: 3)
Environmental History     Hybrid Journal   (Followers: 27, SJR: 0.408, CiteScore: 1)
EP-Europace     Hybrid Journal   (Followers: 2, SJR: 2.748, CiteScore: 4)
Epidemiologic Reviews     Hybrid Journal   (Followers: 9, SJR: 4.505, CiteScore: 8)
ESHRE Monographs     Hybrid Journal  
Essays in Criticism     Hybrid Journal   (Followers: 16, SJR: 0.113, CiteScore: 0)
European Heart J.     Hybrid Journal   (Followers: 57, SJR: 9.315, CiteScore: 9)
European Heart J. - Cardiovascular Imaging     Hybrid Journal   (Followers: 9, SJR: 3.625, CiteScore: 3)
European Heart J. - Cardiovascular Pharmacotherapy     Full-text available via subscription   (Followers: 1)
European Heart J. - Quality of Care and Clinical Outcomes     Hybrid Journal  
European Heart J. : Case Reports     Open Access  
European Heart J. Supplements     Hybrid Journal   (Followers: 8, SJR: 0.223, CiteScore: 0)
European J. of Cardio-Thoracic Surgery     Hybrid Journal   (Followers: 9, SJR: 1.681, CiteScore: 2)
European J. of Intl. Law     Hybrid Journal   (Followers: 181, SJR: 0.694, CiteScore: 1)
European J. of Orthodontics     Hybrid Journal   (Followers: 4, SJR: 1.279, CiteScore: 2)
European J. of Public Health     Hybrid Journal   (Followers: 20, SJR: 1.36, CiteScore: 2)
European Review of Agricultural Economics     Hybrid Journal   (Followers: 10, SJR: 1.172, CiteScore: 2)
European Review of Economic History     Hybrid Journal   (Followers: 28, SJR: 0.702, CiteScore: 1)
European Sociological Review     Hybrid Journal   (Followers: 40, SJR: 2.728, CiteScore: 3)
Evolution, Medicine, and Public Health     Open Access   (Followers: 10)
Family Practice     Hybrid Journal   (Followers: 14, SJR: 1.018, CiteScore: 2)
Fems Microbiology Ecology     Hybrid Journal   (Followers: 10, SJR: 1.492, CiteScore: 4)
Fems Microbiology Letters     Hybrid Journal   (Followers: 22, SJR: 0.79, CiteScore: 2)
Fems Microbiology Reviews     Hybrid Journal   (Followers: 27, SJR: 7.063, CiteScore: 13)
Fems Yeast Research     Hybrid Journal   (Followers: 14, SJR: 1.308, CiteScore: 3)
Food Quality and Safety     Open Access   (Followers: 1)
Foreign Policy Analysis     Hybrid Journal   (Followers: 23, SJR: 1.425, CiteScore: 1)
Forest Science     Hybrid Journal   (Followers: 7, SJR: 0.89, CiteScore: 2)
Forestry: An Intl. J. of Forest Research     Hybrid Journal   (Followers: 16, SJR: 1.133, CiteScore: 3)
Forum for Modern Language Studies     Hybrid Journal   (Followers: 6, SJR: 0.104, CiteScore: 0)
French History     Hybrid Journal   (Followers: 32, SJR: 0.118, CiteScore: 0)
French Studies     Hybrid Journal   (Followers: 20, SJR: 0.148, CiteScore: 0)
French Studies Bulletin     Hybrid Journal   (Followers: 10, SJR: 0.152, CiteScore: 0)
Gastroenterology Report     Open Access   (Followers: 2)
Genome Biology and Evolution     Open Access   (Followers: 12, SJR: 2.578, CiteScore: 4)
Geophysical J. Intl.     Hybrid Journal   (Followers: 35, SJR: 1.506, CiteScore: 3)
German History     Hybrid Journal   (Followers: 22, SJR: 0.161, CiteScore: 0)
GigaScience     Open Access   (Followers: 3, SJR: 5.022, CiteScore: 7)
Global Summitry     Hybrid Journal   (Followers: 1)
Glycobiology     Hybrid Journal   (Followers: 14, SJR: 1.493, CiteScore: 3)
Health and Social Work     Hybrid Journal   (Followers: 56, SJR: 0.388, CiteScore: 1)
Health Education Research     Hybrid Journal   (Followers: 14, SJR: 0.854, CiteScore: 2)
Health Policy and Planning     Hybrid Journal   (Followers: 24, SJR: 1.512, CiteScore: 2)
Health Promotion Intl.     Hybrid Journal   (Followers: 22, SJR: 0.812, CiteScore: 2)
History Workshop J.     Hybrid Journal   (Followers: 29, SJR: 1.278, CiteScore: 1)
Holocaust and Genocide Studies     Hybrid Journal   (Followers: 26, SJR: 0.105, CiteScore: 0)
Human Communication Research     Hybrid Journal   (Followers: 13, SJR: 2.146, CiteScore: 3)
Human Molecular Genetics     Hybrid Journal   (Followers: 8, SJR: 3.555, CiteScore: 5)
Human Reproduction     Hybrid Journal   (Followers: 71, SJR: 2.643, CiteScore: 5)
Human Reproduction Open     Open Access  
Human Reproduction Update     Hybrid Journal   (Followers: 19, SJR: 5.317, CiteScore: 10)
Human Rights Law Review     Hybrid Journal   (Followers: 60, SJR: 0.756, CiteScore: 1)
ICES J. of Marine Science: J. du Conseil     Hybrid Journal   (Followers: 50, SJR: 1.591, CiteScore: 3)
ICSID Review     Hybrid Journal   (Followers: 10)
ILAR J.     Hybrid Journal   (Followers: 2, SJR: 1.732, CiteScore: 4)
IMA J. of Applied Mathematics     Hybrid Journal   (SJR: 0.679, CiteScore: 1)
IMA J. of Management Mathematics     Hybrid Journal   (SJR: 0.538, CiteScore: 1)
IMA J. of Mathematical Control and Information     Hybrid Journal   (Followers: 2, SJR: 0.496, CiteScore: 1)
IMA J. of Numerical Analysis - advance access     Hybrid Journal   (SJR: 1.987, CiteScore: 2)
Industrial and Corporate Change     Hybrid Journal   (Followers: 10, SJR: 1.792, CiteScore: 2)
Industrial Law J.     Hybrid Journal   (Followers: 35, SJR: 0.249, CiteScore: 1)
Inflammatory Bowel Diseases     Hybrid Journal   (Followers: 44, SJR: 2.511, CiteScore: 4)
Information and Inference     Free  
Integrative and Comparative Biology     Hybrid Journal   (Followers: 7, SJR: 1.319, CiteScore: 2)
Interacting with Computers     Hybrid Journal   (Followers: 11, SJR: 0.292, CiteScore: 1)
Interactive CardioVascular and Thoracic Surgery     Hybrid Journal   (Followers: 7, SJR: 0.762, CiteScore: 1)
Intl. Affairs     Hybrid Journal   (Followers: 58, SJR: 1.505, CiteScore: 3)
Intl. Data Privacy Law     Hybrid Journal   (Followers: 31)
Intl. Health     Hybrid Journal   (Followers: 5, SJR: 0.851, CiteScore: 2)
Intl. Immunology     Hybrid Journal   (Followers: 3, SJR: 2.167, CiteScore: 4)
Intl. J. for Quality in Health Care     Hybrid Journal   (Followers: 34, SJR: 1.348, CiteScore: 2)
Intl. J. of Constitutional Law     Hybrid Journal   (Followers: 63, SJR: 0.601, CiteScore: 1)
Intl. J. of Epidemiology     Hybrid Journal   (Followers: 210, SJR: 3.969, CiteScore: 5)
Intl. J. of Law and Information Technology     Hybrid Journal   (Followers: 5, SJR: 0.202, CiteScore: 1)
Intl. J. of Law, Policy and the Family     Hybrid Journal   (Followers: 31, SJR: 0.223, CiteScore: 1)
Intl. J. of Lexicography     Hybrid Journal   (Followers: 10, SJR: 0.285, CiteScore: 1)
Intl. J. of Low-Carbon Technologies     Open Access   (Followers: 1, SJR: 0.403, CiteScore: 1)
Intl. J. of Neuropsychopharmacology     Open Access   (Followers: 3, SJR: 1.808, CiteScore: 4)
Intl. J. of Public Opinion Research     Hybrid Journal   (Followers: 9, SJR: 1.545, CiteScore: 1)
Intl. J. of Refugee Law     Hybrid Journal   (Followers: 35, SJR: 0.389, CiteScore: 1)
Intl. J. of Transitional Justice     Hybrid Journal   (Followers: 12, SJR: 0.724, CiteScore: 2)
Intl. Mathematics Research Notices     Hybrid Journal   (Followers: 1, SJR: 2.168, CiteScore: 1)
Intl. Political Sociology     Hybrid Journal   (Followers: 36, SJR: 1.465, CiteScore: 3)
Intl. Relations of the Asia-Pacific     Hybrid Journal   (Followers: 23, SJR: 0.401, CiteScore: 1)
Intl. Studies Perspectives     Hybrid Journal   (Followers: 9, SJR: 0.983, CiteScore: 1)
Intl. Studies Quarterly     Hybrid Journal   (Followers: 44, SJR: 2.581, CiteScore: 2)
Intl. Studies Review     Hybrid Journal   (Followers: 21, SJR: 1.201, CiteScore: 1)
ISLE: Interdisciplinary Studies in Literature and Environment     Hybrid Journal   (Followers: 1, SJR: 0.15, CiteScore: 0)
ITNOW     Hybrid Journal   (Followers: 1, SJR: 0.103, CiteScore: 0)
J. of African Economies     Hybrid Journal   (Followers: 14, SJR: 0.533, CiteScore: 1)
J. of American History     Hybrid Journal   (Followers: 45, SJR: 0.297, CiteScore: 1)
J. of Analytical Toxicology     Hybrid Journal   (Followers: 14, SJR: 1.065, CiteScore: 2)
J. of Antimicrobial Chemotherapy     Hybrid Journal   (Followers: 15, SJR: 2.419, CiteScore: 4)
J. of Antitrust Enforcement     Hybrid Journal   (Followers: 1)
J. of Applied Poultry Research     Hybrid Journal   (Followers: 4, SJR: 0.585, CiteScore: 1)
J. of Biochemistry     Hybrid Journal   (Followers: 42, SJR: 1.226, CiteScore: 2)
J. of Burn Care & Research     Hybrid Journal   (Followers: 9, SJR: 0.768, CiteScore: 2)
J. of Chromatographic Science     Hybrid Journal   (Followers: 18, SJR: 0.36, CiteScore: 1)
J. of Church and State     Hybrid Journal   (Followers: 11, SJR: 0.139, CiteScore: 0)
J. of Communication     Hybrid Journal   (Followers: 50, SJR: 4.411, CiteScore: 5)
J. of Competition Law and Economics     Hybrid Journal   (Followers: 35, SJR: 0.33, CiteScore: 0)
J. of Complex Networks     Hybrid Journal   (Followers: 2, SJR: 1.05, CiteScore: 4)
J. of Computer-Mediated Communication     Open Access   (Followers: 26, SJR: 2.961, CiteScore: 6)
J. of Conflict and Security Law     Hybrid Journal   (Followers: 12, SJR: 0.402, CiteScore: 0)
J. of Consumer Research     Full-text available via subscription   (Followers: 41, SJR: 5.856, CiteScore: 5)

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Journal Cover
Publications of the Astronomical Society of Japan
Journal Prestige (SJR): 0.877
Citation Impact (citeScore): 1
Number of Followers: 2  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0004-6264 - ISSN (Online) 2053-051X
Published by Oxford University Press Homepage  [396 journals]
  • Supermassive black holes with higher Eddington ratios preferentially form
           in gas-rich galaxies
    • Authors: Izumi T.
      Abstract: The Eddington ratio (λEdd) of supermassive black holes (SMBHs) is a fundamental parameter that governs their cosmic growth. Although gas mass accretion onto SMBHs is sustained when they are surrounded by large amounts of gas, little is known about the molecular content of galaxies, particularly those hosting super-Eddington SMBHs (λEdd > 1: the key phase of SMBH growth). Here, we have compiled reported optical and 12CO(1–0) data of local quasars to characterize their hosts. We found that higher-λEdd SMBHs tend to reside in gas-rich (i.e., high gas mass to stellar mass fraction = fgas) galaxies. We used two methods to make this conclusion: one uses black hole mass as a surrogate for stellar mass by assuming a local co-evolutionary relationship, and the other directly uses stellar masses estimated from near-infrared observations. The fgas–λEdd correlation we found concurs with the cosmic decreasing trend in λEdd, as cold molecular gas is primarily consumed by star formation. This correlation qualitatively matches predictions of recent semi-analytic models of the cosmic downsizing of SMBHs as well. As the gas mass surface density would eventually be a key parameter controlling mass accretion, we need high-resolution observations to identify further differences in the molecular properties around super-Eddington and sub-Eddington SMBHs.
      PubDate: Tue, 15 May 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy045
      Issue No: Vol. 70, No. 3 (2018)
       
  • Detection of the supercycle in V4140 Sagittarii: First eclipsing ER Ursae
           Majoris-like object
    • Authors: Kato T; Hambsch F, Cook L.
      Abstract: We observed the deeply eclipsing SU UMa-type dwarf nova V4140 Sgr and established the very short supercycle of 69.7(3) d. There were several short outbursts between superoutbursts. These values, together with the short orbital period (0.06143 d), were similar to, but not as extreme as, those of ER UMa-type dwarf novae. The object is thus the first, long sought, eclipsing ER UMa-like object. This ER UMa-like nature can naturally explain the high (apparent) quiescent viscosity and unusual temperature profile in quiescence, which were claimed observational features against the thermal–tidal instability model. The apparently unusual outburst behavior can be reasonably explained by a combination of this ER UMa-like nature and the high orbital inclination, and there is no need to introduce mass transfer bursts from its donor star.
      PubDate: Fri, 04 May 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy049
      Issue No: Vol. 70, No. 3 (2018)
       
  • ALMA [C i] observations toward the central region of Seyfert galaxy
           NGC 613
    • Authors: Miyamoto Y; Seta M, Nakai N, et al.
      Abstract: We report ALMA observations of [C i](3P1 − 3P0), 13CO, and C18O(J = 1–0) toward the central region of a nearby Seyfert galaxy NGC 613. The very high resolutions of 0${^{\prime\prime}_{.}}$26 × 0${^{\prime\prime}_{.}}$23 (=22 × 20 pc) for [C i] and 0${^{\prime\prime}_{.}}$42 × 0${^{\prime\prime}_{.}}$35 (=36 × 30 pc) for 13CO, and C18O resolve the circumnuclear disk (CND) and star-forming ring. The distribution of [C i] in the ring resembles that of the CO emission, although [C i] is prominent in the CND. This can be caused by the low intensities of the CO isotopes due to the low optical depths under the high temperature in the CND. We found that the intensity ratios of [C i] to 12CO(3–2) ($R_{\rm C\,{\small I}/CO}$) and to 13CO(1–0) ($R_{\rm C\,{\small I}/^{13}CO}$) are high at several positions around the edge of the ring. The spectral profiles of CO lines mostly correspond each other in the spots of the ring and high $R_{\rm C\,{\small I}/CO}$, but those of [C i] at spots of high $R_{\rm C\,{\small I}/CO}$ are different from those of CO. These results indicate that [C i] at the high $R_{\rm C\,{\small I}/CO}$ traces different gas from that traced by the CO lines. The [C i] kinematics along the minor axis of NGC 613 could be interpreted as a bubbly molecular outflow. The outflow rate of molecular gas is higher than star formation rate in the CND. The flow could be mainly boosted by the active galactic nucleus through its radio jets.
      PubDate: Sat, 07 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy016
      Issue No: Vol. 70, No. 3 (2018)
       
  • Correlation between SiO v = 3 J = 1 → 0 maser excitation and the
           light curve of a long-period variable star
    • Authors: Oyadomari M; Imai H, Nagayama T, et al.
      First page: 33
      Abstract: In order to understand the excitation mechanisms of silicon monoxide (SiO) masers around long-period variables (LPVs), we have investigated distributions of the SiO v = 2 and v = 3 J = 1 → 0 masers around 12 LPVs by very long baseline interferometry (VLBI) observations with the VLBI Exploration of Radio Astrometry (VERA) and the Nobeyama 45 m telescopes. VLBI fringes of the v = 3 maser emission were detected for five LPVs. The composite maps of the v = 2 and v = 3 masers were made for T Cep, W Hya, WX Psc, and R Leo using the spectral line phase-referencing technique. The v = 2 maser spots were distributed in a ring-like form around the central stars, while it is difficult to recognize any specific morphology in the v = 3 maser distributions due to the small number of v = 3 spots detected. However in T Cep, we find that the distribution of the v = 3 maser spots correlates well with the v = 2 masers within a few milliarcseconds (0.2–0.3 au) in position and 1 km s−1 in line-of-sight velocity at the light curve phase of ϕ = 0.28 (ϕ = 0.0 and 1.0 correspond to the visible light maxima). This correlation implies that the mechanism of line-overlapping between the mid-infrared lines of H2O and SiO molecules works in T Cep at ϕ = 0.28. We discuss the possibility that the line-overlapping may work at the limited duration from the maximum to the minimum of the stellar light curve.
      PubDate: Thu, 22 Mar 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy021
      Issue No: Vol. 70, No. 3 (2018)
       
  • Stellar winds and coronae of low-mass Population II/III stars
    • Authors: Suzuki T.
      First page: 34
      Abstract: We investigated stellar winds from zero-/low-metallicity low-mass stars by magnetohydrodynamical simulations for stellar winds driven by Alfvén waves from stars with mass M = (0.6–0.8) M$\odot$ and metallicity Z = (0–1) Z$\odot$, where M$\odot$ and Z$\odot$ are the solar mass and metallicity, respectively. Alfvénic waves, which are excited by the surface convection, travel upward from the photosphere and heat up the corona by their dissipation. For lower Z, denser gas can be heated up to the coronal temperature because of the inefficient radiation cooling. The coronal density of Population II/III stars with Z ≤ 0.01 Z$\odot$ is one to two orders of magnitude larger than that of a solar-metallicity star with the same mass, and as a result, the mass loss rate, $\dot{M}$, is 4.5–20 times larger. This indicates that metal accretion on low-mass Pop. III stars is negligible. The soft X-ray flux of the Pop. II/III stars is also expected to be ∼1–30 times larger than that of a solar-metallicity counterpart owing to the larger coronal density, even though the radiation cooling efficiency is smaller. A larger fraction of the input Alfvénic wave energy is transmitted to the corona in low-Z stars because they avoid severe reflection owing to the smaller density difference between the photosphere and the corona. Therefore, a larger fraction is converted to the thermal energy of the corona and the kinetic energy of the stellar wind. From this energetics argument, we finally derived a scaling of $\dot{M}$ as $\dot{M}\propto L R_{\star }^{11/9}\,M_{\star }^{-10/9}\,T_{\rm eff}^{11/2}\left[\max (Z/Z_{\odot },0.01)\right]^{-1/5}$, where L, R⋆, and Teff are the stellar luminosity, radius, and effective temperature, respectively.
      PubDate: Tue, 03 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy023
      Issue No: Vol. 70, No. 3 (2018)
       
  • The origin of recombining plasma and the detection of the Fe-K line in the
           supernova remnant W 28
    • Authors: Okon H; Uchida H, Tanaka T, et al.
      First page: 35
      Abstract: Overionized recombining plasmas (RPs) have been discovered from a dozen mixed-morphology (MM) supernova remnants (SNRs). However, their formation process is still under debate. As pointed out by many previous studies, spatial variations of plasma temperature and ionization state provide clues to understanding the physical origin of RPs. We report on spatially resolved X-ray spectroscopy of W 28, which is one of the largest MM SNRs found in our Galaxy. Two observations with Suzaku XIS cover the center of W 28 to the northeastern rim where the shock is interacting with molecular clouds. The X-ray spectra in the inner regions are reproduced well by a combination of two RP models with different temperatures and ionization states, whereas that in the northeastern rim is explained with a single RP model. Our discovery of the RP in the northeastern rim suggests an effect of thermal conduction between the cloud and hot plasma, which may be the production process of the RP. The X-ray spectrum of the northeastern rim also shows an excess emission of the Fe i K α line. The most probable process to explain the line would be inner shell ionization of Fe in the molecular cloud by cosmic ray particles accelerated in W 28.
      PubDate: Thu, 22 Mar 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy022
      Issue No: Vol. 70, No. 3 (2018)
       
  • Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). III. Star
           formation properties of the host galaxies at z ≳ 6 studied with ALMA
    • Authors: Izumi T; Onoue M, Shirakata H, et al.
      First page: 36
      Abstract: We present our ALMA Cycle 4 measurements of the [C ii] emission line and the underlying far-infrared (FIR) continuum emission from four optically low-luminosity (M1450 > −25) quasars at z ≳ 6 discovered by the Subaru Hyper Suprime Cam (HSC) survey. The [C ii] line and FIR continuum luminosities lie in the ranges $L_{\rm [C\,{\small {II}}]} = (3.8\mbox{--}10.2)\times 10^{8}\,L_{\odot }$ and LFIR = (1.2–2.0) × 1011 L$_{\odot}$, which are at least one order of magnitude smaller than those of optically-luminous quasars at z ≳ 6. We estimate the star formation rates (SFRs) of our targets as ≃ 23–40 M$_{\odot}$ yr−1. Their line and continuum-emitting regions are marginally resolved, and found to be comparable in size to those of optically-luminous quasars, indicating that their SFR or likely gas mass surface densities (key controlling parameter of mass accretion) are accordingly different. The $L_{\rm [C\,{\small {II}}]}/L_{\rm FIR}$ ratios of the hosts, ≃ (2.2–8.7) × 10−3, are fully consistent with local star-forming galaxies. Using the [C ii] dynamics, we derived their dynamical masses within a radius of 1.5–2.5 kpc as ≃ (1.4–8.2) × 1010 M$_{\odot}$. By interpreting these masses as stellar ones, we suggest that these faint quasar hosts are on or even below the star-forming main sequence at z ∼ 6, i.e., they appear to be transforming into quiescent galaxies. This is in contrast to the optically-luminous quasars at those redshifts, which show starburst-like properties. Finally, we find that the ratios of black hole mass to host galaxy dynamical mass of most of the low-luminosity quasars, including the HSC ones, are consistent with the local value. The mass ratios of the HSC quasars can be reproduced by a semi-analytical model that assumes merger-induced black hole host galaxy evolution.
      PubDate: Tue, 03 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy026
      Issue No: Vol. 70, No. 3 (2018)
       
  • Large velocity dispersion of molecular gas in bars of strongly barred
           galaxies NGC 1300 and NGC 5383
    • Authors: Maeda F; Ohta K, Fujimoto Y, et al.
      First page: 37
      Abstract: We carried out $\sf ^{12}$CO(J = 1–0) observations toward bar and arm regions of the strongly barred galaxies NGC 1300 and NGC 5383 with the Nobeyama 45 m radio telescope (beam size of 1–2 kpc in the galaxies). The aim of the observations is to qualitatively examine a new scenario for the suppression of star formation in bars based on recent high-resolution numerical simulations: higher speed collisions between molecular clouds in the bar region compared with the arm region suppress the massive star formation. CO emissions were detected from all the regions, indicating the presence of molecular gases in the strong bars without associating clear H II regions. In both galaxies, the velocity width of the CO line profile tends to be larger in the bar region than in the arm region, which is qualitatively consistent with the new scenario.
      PubDate: Thu, 22 Mar 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy028
      Issue No: Vol. 70, No. 3 (2018)
       
  • Hitomi X-ray observation of the pulsar wind nebula G21.5−0.9
    • First page: 38
      Abstract: We present results from the Hitomi X-ray observation of a young composite-type supernova remnant (SNR) G21.5−0.9, whose emission is dominated by the pulsar wind nebula (PWN) contribution. The X-ray spectra in the 0.8–80 keV range obtained with the Soft X-ray Spectrometer (SXS), Soft X-ray Imager, and Hard X-ray Imager (HXI) show a significant break in the continuum as previously found with the NuSTAR observation. After taking into account all known emissions from the SNR other than the PWN itself, we find that the Hitomi spectra can be fitted with a broken power law with photon indices of Γ1 = 1.74 ± 0.02 and Γ2 = 2.14 ± 0.01 below and above the break at 7.1 ± 0.3 keV, which is significantly lower than the NuSTAR result (∼9.0 keV). The spectral break cannot be reproduced by time-dependent particle injection one-zone spectral energy distribution models, which strongly indicates that a more complex emission model is needed, as suggested by recent theoretical models. We also search for narrow emission or absorption lines with the SXS, and perform a timing analysis of PSR J1833−1034 with the HXI and the Soft Gamma-ray Detector. No significant pulsation is found from the pulsar. However, unexpectedly, narrow absorption line features are detected in the SXS data at 4.2345 keV and 9.296 keV with a significance of 3.65 σ. While the origin of these features is not understood, their mere detection opens up a new field of research and was only possible with the high resolution, sensitivity, and ability to measure extended sources provided by an X-ray microcalorimeter.
      PubDate: Tue, 03 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy027
      Issue No: Vol. 70, No. 3 (2018)
       
  • Repeating and non-repeating fast radio bursts from binary neutron star
           mergers
    • Authors: Yamasaki S; Totani T, Kiuchi K.
      First page: 39
      Abstract: Most fast radio bursts (FRB) do not show evidence of repetition, and such non-repeating FRBs may be produced at the time of a merger of binary neutron stars (BNS), provided that the BNS merger rate is close to the high end of the currently possible range. However, the merger environment is polluted by dynamical ejecta, which may prohibit the radio signal from propagating. We examine this by using a general-relativistic simulation of a BNS merger, and show that the ejecta appears about 1 ms after the rotation speed of the merged star becomes the maximum. Therefore there is a time window in which an FRB signal can reach outside, and the short duration of non-repeating FRBs can be explained by screening after ejecta formation. A fraction of BNS mergers may leave a rapidly rotating and stable neutron star, and such objects may be the origin of repeating FRBs like FRB 121102. We show that a merger remnant would appear as a repeating FRB on a time scale of ∼1–10 yr, and expected properties are consistent with the observations of FRB 121102. We construct an FRB rate evolution model that includes these two populations of repeating and non-repeating FRBs from BNS mergers, and show that the detection rate of repeating FRBs relative to non-repeating ones rapidly increases with improving search sensitivity. This may explain why only the repeating FRB 121102 was discovered by the most sensitive FRB search with Arecibo. Several predictions are made, including the appearance of a repeating FRB 1–10 yr after a BNS merger that is localized by gravitational waves and subsequent electromagnetic radiation.
      PubDate: Tue, 03 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy029
      Issue No: Vol. 70, No. 3 (2018)
       
  • Spectroscopic abundance analyses of the 3He stars HD 185330 and
           3 Cen A
    • Authors: Sadakane K; Nishimura M.
      First page: 40
      Abstract: Abundances of 21 elements in two 3He stars, HD 185330 and 3 Cen A, have been analysed relative to the well-studied sharp-lined B3 V star ι Her. Six elements (P, Ti, Mn, Fe, Ni, and Br) are over-abundant in these two peculiar stars, while six elements (C, O, Mg, Al, S, and Cl) are under-abundant. Absorption lines of the two rarely observed heavy elements Br ii and Kr ii are detected in both stars and these elements are both over-abundant. The centroid wavelengths of the Ca ii infrared triplet lines in these stars are redshifted relative to those lines in ι Her and the presence of heavy isotopes of Ca (mass number 44–46) in these two stars is confirmed. In spite of these similarities, there are several remarkable differences in abundance pattern between these two stars. N is under-abundant in HD 185330, as in many Hg-Mn stars, while it is significantly over-abundant in 3 Cen A. P and Ga are both over-abundant in 3 Cen A, while only P is over-abundant and no trace of absorption line of Ga ii can be found in HD 185330. Large over-abundances of Kr and Xe are found in both stars, while the abundance ratio Kr/Xe is significantly different between them (−1.4 dex in HD 185330 and +1.2 dex in 3 Cen A). Some physical explanations are needed to account for these qualitative differences.
      PubDate: Tue, 03 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy031
      Issue No: Vol. 70, No. 3 (2018)
       
  • The Subaru FMOS galaxy redshift survey (FastSound). V. Intrinsic
           alignments of emission-line galaxies at z ∼ 1.4
    • Authors: Tonegawa M; Okumura T, Totani T, et al.
      First page: 41
      Abstract: Intrinsic alignments (IA), the coherent alignment of intrinsic galaxy orientations, can be a source of a systematic error of weak lensing surveys. The redshift evolution of IA also contains information about the physics of galaxy formation and evolution. This paper presents the first measurement of IA at high redshift, z ∼ 1.4, using the spectroscopic catalog of blue star-forming galaxies of the FastSound redshift survey, with the galaxy shape information from the Canada–Hawaii–France telescope lensing survey. The IA signal is consistent with zero with power-law amplitudes fitted to the projected correlation functions for density–shape and shape–shape correlation components, Aδ+ = −0.0071 ± 0.1340 and A++ = −0.0505 ± 0.0848, respectively. These results are consistent with those obtained from blue galaxies at lower redshifts (e.g., $A\,_{\delta +}=0.0035_{-0.0389}^{+0.0387}$ and $A_{++}=0.0045_{-0.0168}^{+0.0166}$ at z = 0.51 from the WiggleZ survey). The upper limit of the constrained IA amplitude corresponds to a few percent contamination to the weak-lensing shear power spectrum, resulting in systematic uncertainties on the cosmological parameter estimations by −0.052 < Δσ8 < 0.039 and −0.039 < ΔΩm < 0.030.
      PubDate: Sat, 14 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy030
      Issue No: Vol. 70, No. 3 (2018)
       
  • Can the relativistic light-bending model explain X-ray spectral variations
           of Seyfert galaxies'
    • Authors: Mizumoto M; Moriyama K, Ebisawa K, et al.
      First page: 42
      Abstract: Many Seyfert galaxies are known to exhibit Fe-K broad emission line features in their X-ray energy spectra. The observed lines have three distinct features: (1) the line profiles are skewed and show significant low-energy tails, (2) the Fe-K band has low variability, which produces a broad and deep dip in the root-mean-square (rms) spectra, and (3) photons in this band have time lags behind those in the adjacent energy bands with amplitudes of several Rg/c, where Rg is the gravitational radius. The “relativistic light-bending model” is proposed to explain these observed features, where a compact X-ray source (“lamp post”) above an extreme Kerr black hole illuminates the innermost area of the accretion disc. In this paper, we critically examine the relativistic light-bending model by computing the rms spectra and the lag features using a ray-tracing technique, when a lamp post moves vertically on the black hole spin axis. As a result, we found that the observed deep rms dip requires that the iron is extremely overabundant (≳10 solar), whereas the observed lag amplitude is consistent with the normal iron abundance. Furthermore, disappearance of the lag in the high-flux state requires a source height as high as ∼40 Rg, which contradicts the relativistically broad emission line feature. Our simulations agree with the data that the reverberation feature moves to lower frequencies with larger source height; however, if this scenario is correct, the simulations predict the detection of a clear Fe-K lag at low frequencies, which is not constrained in the data. Therefore, we conclude that the relativistic light-bending model may not explain the characteristic Fe-K spectral variations in Seyfert galaxies.
      PubDate: Tue, 03 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy032
      Issue No: Vol. 70, No. 3 (2018)
       
  • Similarity solutions of time-dependent relativistic
           radiation-hydrodynamical plane-parallel flows
    • Authors: Fukue J.
      First page: 43
      Abstract: Similarity solutions are examined for the frequency-integrated relativistic radiation-hydrodynamical flows, which are described by the comoving quantities. The flows are vertical plane-parallel time-dependent ones with a gray opacity coefficient. For adequate boundary conditions, the flows are accelerated in a somewhat homologous manner, but terminate at some singular locus, which originates from the pathological behavior in relativistic radiation moment equations truncated in finite orders.
      PubDate: Tue, 03 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy034
      Issue No: Vol. 70, No. 3 (2018)
       
  • Mid-infrared multi-wavelength imaging of Ophiuchus IRS 48
           transitional disk†
    • Authors: Honda M; Okada K, Miyata T, et al.
      First page: 44
      Abstract: Transitional disks around the Herbig Ae/Be stars are fascinating targets in the contexts of disk evolution and planet formation. Oph IRS 48 is one of such Herbig Ae stars, which shows an inner dust cavity and azimuthally lopsided large dust distribution. We present new images of Oph IRS 48 at eight mid-infrared (MIR) wavelengths from 8.59 to 24.6 μm taken with COMICS mounted on the 8.2 m Subaru Telescope. The N-band (7 to 13 μm) images show that the flux distribution is centrally peaked with a slight spatial extent, while the Q-band (17 to 25 μm) images show asymmetric double peaks (east and west). Using 18.8- and 24.6 μm images, we derived the dust temperature at both east and west peaks to be 135 ±  22 K. Thus, the asymmetry may not be attributed to a difference in the temperature. Comparing our results with previous modeling works, we conclude that the inner disk is aligned to the outer disk. A shadow cast by the optically thick inner disk has a great influence on the morphology of MIR thermal emission from the outer disk.
      PubDate: Thu, 05 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy033
      Issue No: Vol. 70, No. 3 (2018)
       
  • Exploring the origin of broad-band emissions of Mrk 501 with a
           two-zone model
    • Authors: Lei M; Yang C, Wang J, et al.
      First page: 45
      Abstract: We propose a two-zone synchrotron self-Compton (SSC) model, including an inner gamma-ray emitting region with spherical shape and a conical radio emitting region located at the extended jet, to alleviate the long-standing “bulk Lorentz factor crisis” in blazars. In this model, the spectral energy distributions (SEDs) of blazars are produced by considering the gamma-ray emitting region inverse Compton scattering of both the synchrotron photons itself and the ambient photons from the radio emitting region. Applying the model to Mrk 501, we obtain that the radio emitting region has a comoving length of ∼0.15 pc and is located at sub-parsec scale from the central engine by modeling the radio data; the flux of the Compton scattering of the ambient photons is so low that it can be neglected safely. The characteristic hard gamma-ray spectrum can be explained by the superposition of two SSC processes, and the model can approximately explain the very high energy (VHE) data. The insights into the spectral shape and the inter-band correlations under the flaring state will provide us with a diagnostic for the bulk Lorentz factor of radio emitting region, where the low and upper limits of 8 and 15 are preferred, and for the two-zone SSC model itself. In addition, our two-zone SSC model shows that the gamma-ray emitting region creates flare on the timescale of merely a few hours, and the long time outbursts more likely originate from the extended radio emitting region.
      PubDate: Wed, 18 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy035
      Issue No: Vol. 70, No. 3 (2018)
       
  • Suzaku observations of low surface brightness cluster Abell 1631
    • Authors: Babazaki Y; Mitsuishi I, Ota N, et al.
      First page: 46
      Abstract: We present analysis results for a nearby galaxy cluster Abell 1631 at z = 0.046 using the X-ray observatory Suzaku. This cluster is categorized as a low X-ray surface brightness cluster. To study the dynamical state of the cluster, we conduct four-pointed Suzaku observations and investigate physical properties of the Mpc-scale hot gas associated with the A 1631 cluster for the first time. Unlike relaxed clusters, the X-ray image shows no strong peak at the center and an irregular morphology. We perform spectral analysis and investigate the radial profiles of the gas temperature, density, and entropy out to approximately 1.5 Mpc in the east, north, west, and south directions by combining with the XMM-Newton data archive. The measured gas density in the central region is relatively low (a few ×10−4 cm−3) at the given temperature (∼2.9 keV) compared with X-ray-selected clusters. The entropy profile and value within the central region (r < 0.1 r200) are found to be flatter and higher (≳400 keV cm2). The observed bolometric luminosity is approximately three times lower than that expected from the luminosity–temperature relation in previous studies of relaxed clusters. These features are also observed in another low surface brightness cluster, Abell 76. The spatial distributions of galaxies and the hot gas appear to be different. The X-ray luminosity is relatively lower than that expected from the velocity dispersion. A post-merger scenario may explain the observed results.
      PubDate: Tue, 10 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy036
      Issue No: Vol. 70, No. 3 (2018)
       
  • ASASSN-16dt and ASASSN-16hg: Promising candidate period bouncers
    • Authors: Kimura M; Isogai K, Kato T, et al.
      First page: 47
      Abstract: We present optical photometry of superoutbursts that occurred in 2016 of two WZ Sge-type dwarf novae (DNe), ASASSN-16dt and ASASSN-16hg. Their light curves showed a dip in brightness between the first plateau stage with no ordinary superhumps (or early superhumps) and the second plateau stage with ordinary superhumps. We find that the dip is produced by the slow evolution of the 3 : 1 resonance tidal instability and that it would likely be observed in low mass-ratio objects. An estimated mass ratio (q ≡ M2/M1) from the period of developing (stage A) superhumps [0.06420(3) d] was 0.036(2) in ASASSN-16dt. Additionally, its superoutburst has many properties similar to those in other low-q WZ Sge-type DNe: long-lasting stage-A superhumps, small superhump amplitudes, long delay of ordinary-superhump appearances, and a slow decline rate in the plateau stage with superhumps. Its very small mass ratio and observational characteristics suggest that this system is one of the best candidates for a period bouncer—a binary accounting for the missing population of post-period minimum cataclysmic variables. Although it is not clearly verified due to the lack of detection of stage-A superhumps, ASASSN-16hg might be a possible candidate for period bouncers on the basis of the morphology of its light curves and the small superhump amplitudes. Many outburst properties of period bouncer candidates would originate from the small tidal effects of their secondary stars.
      PubDate: Mon, 23 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy037
      Issue No: Vol. 70, No. 3 (2018)
       
  • Gas, dust, stars, star formation, and their evolution in M 33 at
           giant molecular cloud scales
    • Authors: Komugi S; Miura R, Kuno N, et al.
      First page: 48
      Abstract: We report on a multi-parameter analysis of giant molecular clouds (GMCs) in the nearby spiral galaxy M 33. A catalog of GMCs identifed in 12CO(J = 3–2) was used to compile associated 12CO(J = 1–0), dust, stellar mass, and star formation rate. Each of the 58 GMCs are categorized by their evolutionary stage. Applying the principal component analysis on these parameters, we construct two principal components, PC1 and PC2, which retain 75% of the information from the original data set. PC1 is interpreted as expressing the total interstellar matter content, and PC2 as the total activity of star formation. Young (< 10 Myr) GMCs occupy a distinct region in the PC1–PC2 plane, with lower interstellar medium (ISM) content and star formation activity compared to intermediate-age and older clouds. Comparison of average cloud properties in different evolutionary stages imply that GMCs may be heated or grow denser and more massive via aggregation of diffuse material in their first ∼ 10 Myr. The PCA also objectively identified a set of tight relations between ISM and star formation. The ratio of the two CO lines is nearly constant, but weakly modulated by massive star formation. Dust is more strongly correlated with the star formation rate than the CO lines, supporting recent findings that dust may trace molecular gas better than CO. Stellar mass contributes weakly to the star formation rate, reminiscent of an extended form of the Schmidt–Kennicutt relation with the molecular gas term substituted by dust.
      PubDate: Sat, 14 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy038
      Issue No: Vol. 70, No. 3 (2018)
       
  • High-energy gamma-ray and neutrino production in star-forming galaxies
           across cosmic time: Difficulties in explaining the IceCube data
    • Authors: Sudoh T; Totani T, Kawanaka N.
      First page: 49
      Abstract: We present new theoretical modeling to predict the luminosity and spectrum of gamma-ray and neutrino emission of a star-forming galaxy, from the star formation rate (ψ), gas mass (Mgas), stellar mass, and disk size, taking into account production, propagation, and interactions of cosmic rays. The model reproduces the observed gamma-ray luminosities of nearby galaxies detected by Fermi better than the simple power-law models as a function of ψ or ψMgas. This model is then used to predict the cosmic background flux of gamma-rays and neutrinos from star-forming galaxies, by using a semi-analytical model of cosmological galaxy formation that reproduces many observed quantities of local and high-redshift galaxies. Calibration of the model using gamma-ray luminosities of nearby galaxies allows us to make a more reliable prediction than previous studies. In our baseline model, star-forming galaxies produce about 20% of the isotropic gamma-ray background unresolved by Fermi, and only 0.5% of IceCube neutrinos. Even with an extreme model assuming a hard injection cosmic-ray spectral index of 2.0 for all galaxies, at most 22% of IceCube neutrinos can be accounted for. These results indicate that it is difficult to explain most of the IceCube neutrinos by star-forming galaxies, without violating the gamma-ray constraints from nearby galaxies.
      PubDate: Sat, 14 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy039
      Issue No: Vol. 70, No. 3 (2018)
       
  • Spin temperature and density of cold and warm H i in the Galactic
           disk: Hidden H i
    • Authors: Sofue Y.
      First page: 50
      Abstract: We present a method to determine the spin temperature TS and volume density n of H i gas simultaneously along the tangent-point circle of Galactic rotation in the Milky Way by using the χ2 method. The best-fit TS is shown to range either in TS ∼ 100–120 K or in 1000–3000 K, indicating that the gas is in the cold H i phase with high density and large optical depth, or in warm H i with low density and small optical depth. Averaged values at 3 ≤ R ≤ 8 kpc are obtained to be TS = 106.7 ± 16.0 K and n = 1.53 ± 0.86 H cm−3 for cold H i, and 1720 ± 1060 K and 0.38 ± 0.10 H cm−3 for warm H i, where R = 8  sinl  kpc is the galacto-centric distance along the tangent-point circle. The cold H i appears in spiral arms and rings, whereas warm H i appears in the inter-arm regions. The cold H i is denser by a factor of ∼4 than warm H i. The present analysis has revealed the hidden H i mass in the cold and optically thick phase in the Galactic disk. The total H i mass inside the solar circle is shown to be greater by a factor of 2–2.5 than the current estimation by the optically thin assumption.
      PubDate: Sat, 05 May 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy044
      Issue No: Vol. 70, No. 3 (2018)
       
  • Constraining hydrostatic mass bias of galaxy clusters with high-resolution
           X-ray spectroscopy
    • Authors: Ota N; Nagai D, Lau E.
      First page: 51
      Abstract: Gas motions in galaxy clusters play important roles in determining the properties of the intracluster medium (ICM) and in the constraint of cosmological parameters via X-ray and Sunyaev–Zel’dovich effect observations of galaxy clusters. The Hitomi measurements of gas motions in the core of the Perseus Cluster have provided new insights into the physics in galaxy clusters. The XARM mission, equipped with the Resolve X-ray micro-calorimeter, will continue Hitomi’s legacy by measuring ICM motions through Doppler shifting and broadening of emission lines in a larger number of galaxy clusters, and at larger radii. In this work, we investigate how well we can measure bulk and turbulent gas motions in the ICM with XARM, by analyzing mock XARM simulations of galaxy clusters extracted from cosmological hydrodynamic simulations. We assess how photon counts, spectral fitting methods, multiphase ICM structure, deprojections, and region selection affect the measurements of gas motions. We first show that XARM is capable of recovering the underlying spherically averaged turbulent and bulk velocity profiles for dynamically relaxed clusters to within ∼50% with a reasonable amount of photon counts in the X-ray emission lines. We also find that there are considerable azimuthal variations in the ICM velocities, where the velocities measured in a single azimuthal direction can significantly deviate from the true value even in dynamically relaxed systems. Such variation must be taken into account when interpreting data and developing observing strategies. We will discuss the prospect of using the upcoming XARM mission to measure non-thermal pressure and to correct for the hydrostatic mass bias of galaxy clusters. Our results are broadly applicable for future X-ray missions, such as Athena and Lynx.
      PubDate: Fri, 27 Apr 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy040
      Issue No: Vol. 70, No. 3 (2018)
       
  • Mechanisms for the elevation structure of a giant telescope
    • Authors: Hu S; Song X, Zhang H.
      First page: 52
      Abstract: This paper describes an innovative mechanism based on hydrostatic pads and linear motors for the elevation structure of next-generation extremely large telescopes. Both hydrostatic pads and linear motors are integrated on the frame that includes a kinematical joint, such that the upper part is properly positioned with respect to the elevation runner tracks, while the lower part is connected to the azimuth structure. Potential deflections of the elevation runner bearings at the radial pad locations are absorbed by this flexible kinematic connection and not transmitted to the linear motors and hydrostatic pads. Extensive simulations using finite-element analysis are carried out to verify that the auxiliary whiffletree hydraulic design of the mechanism is sufficient to satisfy the assigned optical length variation errors.
      PubDate: Thu, 03 May 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy043
      Issue No: Vol. 70, No. 3 (2018)
       
  • ATCA 16 cm observation of CIZA J1358.9−4750: Implication of merger stage
           and constraint on non-thermal properties
    • Authors: Akahori T; Kato Y, Nakazawa K, et al.
      First page: 53
      Abstract: We report the Australia Telescope Compact Array 16 cm observation of CIZA J1358.9−4750. Recent X-ray studies imply that this galaxy cluster is composed of merging, binary clusters. Using the EW367 configuration, we found no significant diffuse radio emission in and around the cluster. An upper limit of the total radio power at 1.4 GHz is ∼1.1 × 1022 W Hz−1 in 30 square arcminutes, which is a typical size for radio relics. It is known that an empirical relation holds between the total radio power and X-ray luminosity of the host cluster. The upper limit is about one order of magnitude lower than the power expected from the relation. Very young (∼70 Myr) shocks with low Mach numbers (∼1.3), which are often seen at an early stage of merger simulations, are suggested by the previous X-ray observation. The shocks may generate cosmic-ray electrons with a steep energy spectrum, which is consistent with non-detection of bright (>1023 W Hz−1) relic in this 16 cm band observation. Based on the assumption of energy equipartition, the upper limit gives a magnetic field strength of below 0.68f(Dlos/1 Mpc)−1(γmin/200)−1 μG, where f is the cosmic-ray total energy density over the cosmic-ray electron energy density, Dlos is the depth of the shock wave along the sightline, and γmin is the lower cutoff Lorentz factor of the cosmic-ray electron energy spectrum.
      PubDate: Fri, 18 May 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy042
      Issue No: Vol. 70, No. 3 (2018)
       
  • Searches for H2O masers toward narrow-line Seyfert 1 galaxies
    • Authors: Hagiwara Y; Doi A, Hachisuka K, et al.
      First page: 54
      Abstract: We present searches for 22 GHz H2O masers toward 36 narrow-line Seyfert 1 galaxies (NLS1s), selected from known NLS1s with $v$sys ≲ 41000 km s−1. Out of the 36 NLS1s in our sample, 11 have been first surveyed in our observations, while the observations of other NLS1s were previously reported in literature. In our survey, no new water maser source from NLS1s was detected at the 3σ rms level of 8.4 mJy to 144 mJy, which depends on different observing conditions or inhomogeneous sensitivities of each observation using three different telescopes. It is likely that the non-detection of new masers in our NLS1 sample is primarily due to insufficient sensitivities of our observations. Including the five known NLS1 masers, the total detection rate of the H2O maser in NLS1s is not remarkably different from that of type 2 Seyfert galaxies or LINERs. However, more extensive and systematic searches of NLS1 would be required for a statistical discussion of the detection rate of the NLS1 maser, compared with that of type 2 Seyferts or LINERs.
      PubDate: Fri, 04 May 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy046
      Issue No: Vol. 70, No. 3 (2018)
       
  • SILVERRUSH. VI. A simulation of Lyα emitters in the reionization epoch
           and a comparison with Subaru Hyper Suprime-Cam survey early data
    • Authors: Inoue A; Hasegawa K, Ishiyama T, et al.
      First page: 55
      Abstract: The survey of Lyman α emitters (LAEs) with the Subaru Hyper Suprime-Cam, called SILVERRUSH (Ouchi et al. 2018, PASJ, 70, S13), is producing massive data of LAEs at z ≳ 6. Here we present LAE simulations to compare the SILVERRUSH data. In 1623 comoving Mpc3 boxes, where numerical radiative transfer calculations of reionization were performed, LAEs have been modeled with physically motivated analytic recipes as a function of halo mass. We have examined 23 models depending on the presence or absence of dispersion of halo Lyα emissivity, dispersion of the halo Lyα optical depth, τα, and halo mass dependence of τα. The unique free parameter in our model, a pivot value of τα, is calibrated so as to reproduce the z = 5.7 Lyα luminosity function (LF) of SILVERRUSH. We compare our model predictions with Lyα LFs at z = 6.6 and 7.3, LAE angular auto-correlation functions (ACFs) at z = 5.7 and 6.6, and LAE fractions in Lyman break galaxies at 5 < z < 7. The Lyα LFs and ACFs are reproduced by multiple models, but the LAE fraction turns out to be the most critical test. The dispersion of τα and the halo mass dependence of τα are essential to explain all observations reasonably. Therefore, a simple model of one-to-one correspondence between halo mass and Lyα luminosity with a constant Lyα escape fraction has been ruled out. Based on our best model, we present a formula to estimate the intergalactic neutral hydrogen fraction, $x_{\rm H\, \small {I}}$, from the observed Lyα luminosity density at z ≳ 6. We finally obtain $x_{\rm H\, \small {I}}=0.5_{-0.3}^{+0.1}$ as a volume-average at z = 7.3.
      PubDate: Tue, 15 May 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy048
      Issue No: Vol. 70, No. 3 (2018)
       
  • Erratum to: Multiwavelength study of X-ray luminous clusters in the Hyper
           Suprime-Cam Subaru Strategic Program S16A field†
    • Authors: Miyaoka K; Okabe N, Kitaguchi T, et al.
      First page: 56
      PubDate: Mon, 12 Mar 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy024
      Issue No: Vol. 70, No. 3 (2018)
       
  • Erratum to: Suzaku Observations of Low Surface Brightness Cluster Abell
           1631
    • Authors: Babazaki Y; Mitsuishi I, Ota N, et al.
      First page: 57
      PubDate: Fri, 15 Jun 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy063
      Issue No: Vol. 70, No. 3 (2018)
       
 
 
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