for Journals by Title or ISSN
for Articles by Keywords

Publisher: Oxford University Press   (Total: 406 journals)

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2 3 | Last   [Sort by number of followers]   [Restore default list]

Showing 1 - 200 of 406 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: 9, SJR: 0.143, CiteScore: 0)
Advances in Nutrition     Hybrid Journal   (Followers: 53, SJR: 2.196, CiteScore: 5)
Aesthetic Surgery J.     Hybrid Journal   (Followers: 6, SJR: 1.434, CiteScore: 1)
Aesthetic Surgery J. Open Forum     Open Access  
African Affairs     Hybrid Journal   (Followers: 66, SJR: 1.869, CiteScore: 2)
Age and Ageing     Hybrid Journal   (Followers: 90, SJR: 1.989, CiteScore: 4)
Alcohol and Alcoholism     Hybrid Journal   (Followers: 19, SJR: 1.376, CiteScore: 3)
American Entomologist     Full-text available via subscription   (Followers: 8)
American Historical Review     Hybrid Journal   (Followers: 162, SJR: 0.467, CiteScore: 1)
American J. of Agricultural Economics     Hybrid Journal   (Followers: 44, SJR: 2.113, CiteScore: 3)
American J. of Clinical Nutrition     Hybrid Journal   (Followers: 170, SJR: 3.438, CiteScore: 6)
American J. of Epidemiology     Hybrid Journal   (Followers: 194, SJR: 2.713, CiteScore: 3)
American J. of Health-System Pharmacy     Full-text available via subscription   (Followers: 52, SJR: 0.595, CiteScore: 1)
American J. of Hypertension     Hybrid Journal   (Followers: 25, SJR: 1.322, CiteScore: 3)
American J. of Jurisprudence     Hybrid Journal   (Followers: 19, SJR: 0.281, CiteScore: 1)
American J. of Legal History     Full-text available via subscription   (Followers: 9, 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: 16, SJR: 0.391, CiteScore: 0)
Analysis     Hybrid Journal   (Followers: 22, SJR: 1.038, CiteScore: 1)
Animal Frontiers     Hybrid Journal   (Followers: 1)
Annals of Behavioral Medicine     Hybrid Journal   (Followers: 16, SJR: 1.423, CiteScore: 3)
Annals of Botany     Hybrid Journal   (Followers: 38, SJR: 1.721, CiteScore: 4)
Annals of Oncology     Hybrid Journal   (Followers: 56, SJR: 5.599, CiteScore: 9)
Annals of the Entomological Society of America     Full-text available via subscription   (Followers: 10, SJR: 0.722, CiteScore: 1)
Annals of Work Exposures and Health     Hybrid Journal   (Followers: 34, SJR: 0.728, CiteScore: 2)
Antibody Therapeutics     Open Access  
AoB Plants     Open Access   (Followers: 4, SJR: 1.28, CiteScore: 3)
Applied Economic Perspectives and Policy     Hybrid Journal   (Followers: 18, SJR: 0.858, CiteScore: 2)
Applied Linguistics     Hybrid Journal   (Followers: 59, 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: 44, SJR: 0.146, CiteScore: 0)
Behavioral Ecology     Hybrid Journal   (Followers: 52, SJR: 1.871, CiteScore: 3)
Bioinformatics     Hybrid Journal   (Followers: 331, SJR: 6.14, CiteScore: 8)
Biology Methods and Protocols     Hybrid Journal  
Biology of Reproduction     Full-text available via subscription   (Followers: 9, SJR: 1.446, CiteScore: 3)
Biometrika     Hybrid Journal   (Followers: 20, SJR: 3.485, CiteScore: 2)
BioScience     Hybrid Journal   (Followers: 29, 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: 181, SJR: 2.115, CiteScore: 3)
BJA Education     Hybrid Journal   (Followers: 65)
Brain     Hybrid Journal   (Followers: 68, SJR: 5.858, CiteScore: 7)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 51, 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: 36, SJR: 2.161, CiteScore: 2)
British J. of Aesthetics     Hybrid Journal   (Followers: 25, SJR: 0.508, CiteScore: 1)
British J. of Criminology     Hybrid Journal   (Followers: 597, SJR: 1.828, CiteScore: 3)
British J. of Social Work     Hybrid Journal   (Followers: 86, SJR: 1.019, CiteScore: 2)
British Medical Bulletin     Hybrid Journal   (Followers: 6, SJR: 1.355, CiteScore: 3)
British Yearbook of Intl. Law     Hybrid Journal   (Followers: 34)
Bulletin of the London Mathematical Society     Hybrid Journal   (Followers: 4, SJR: 1.376, CiteScore: 1)
Cambridge J. of Economics     Hybrid Journal   (Followers: 68, SJR: 0.764, CiteScore: 2)
Cambridge J. of Regions, Economy and Society     Hybrid Journal   (Followers: 12, SJR: 2.438, CiteScore: 4)
Cambridge Quarterly     Hybrid Journal   (Followers: 10, 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: 47, SJR: 3.892, CiteScore: 6)
CESifo Economic Studies     Hybrid Journal   (Followers: 22, SJR: 0.483, CiteScore: 1)
Chemical Senses     Hybrid Journal   (Followers: 1, SJR: 1.42, CiteScore: 3)
Children and Schools     Hybrid Journal   (Followers: 6, SJR: 0.246, CiteScore: 0)
Chinese J. of Comparative Law     Hybrid Journal   (Followers: 5, 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: 10, 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: 27, SJR: 0.123, CiteScore: 0)
Clean Energy     Open Access   (Followers: 1)
Clinical Infectious Diseases     Hybrid Journal   (Followers: 69, SJR: 5.051, CiteScore: 5)
Communication Theory     Hybrid Journal   (Followers: 24, SJR: 2.424, CiteScore: 3)
Communication, Culture & Critique     Hybrid Journal   (Followers: 27, 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: 3, 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: 6, SJR: 0.906, CiteScore: 1)
Critical Values     Full-text available via subscription  
Current Developments in Nutrition     Open Access   (Followers: 2)
Current Legal Problems     Hybrid Journal   (Followers: 29)
Current Zoology     Full-text available via subscription   (Followers: 3, 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: 14, 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: 4)
Early Music     Hybrid Journal   (Followers: 16, SJR: 0.139, CiteScore: 0)
Econometrics J.     Hybrid Journal   (Followers: 30, SJR: 2.926, CiteScore: 1)
Economic J.     Hybrid Journal   (Followers: 106, SJR: 5.161, CiteScore: 3)
Economic Policy     Hybrid Journal   (Followers: 46, SJR: 3.584, CiteScore: 3)
ELT J.     Hybrid Journal   (Followers: 24, SJR: 0.942, CiteScore: 1)
English Historical Review     Hybrid Journal   (Followers: 56, SJR: 0.612, CiteScore: 1)
English: J. of the English Association     Hybrid Journal   (Followers: 17, SJR: 0.1, CiteScore: 0)
Environmental Entomology     Full-text available via subscription   (Followers: 11, SJR: 0.818, CiteScore: 2)
Environmental Epigenetics     Open Access   (Followers: 2)
Environmental History     Hybrid Journal   (Followers: 26, SJR: 0.408, CiteScore: 1)
EP-Europace     Hybrid Journal   (Followers: 3, 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: 19, SJR: 0.113, CiteScore: 0)
European Heart J.     Hybrid Journal   (Followers: 66, SJR: 9.315, CiteScore: 9)
European Heart J. - Cardiovascular Imaging     Hybrid Journal   (Followers: 11, SJR: 3.625, CiteScore: 3)
European Heart J. - Cardiovascular Pharmacotherapy     Full-text available via subscription   (Followers: 2)
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: 198, 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: 30, SJR: 0.702, CiteScore: 1)
European Sociological Review     Hybrid Journal   (Followers: 42, SJR: 2.728, CiteScore: 3)
Evolution, Medicine, and Public Health     Open Access   (Followers: 12)
Family Practice     Hybrid Journal   (Followers: 16, SJR: 1.018, CiteScore: 2)
Fems Microbiology Ecology     Hybrid Journal   (Followers: 16, SJR: 1.492, CiteScore: 4)
Fems Microbiology Letters     Hybrid Journal   (Followers: 28, SJR: 0.79, CiteScore: 2)
Fems Microbiology Reviews     Hybrid Journal   (Followers: 32, SJR: 7.063, CiteScore: 13)
Fems Yeast Research     Hybrid Journal   (Followers: 13, SJR: 1.308, CiteScore: 3)
Food Quality and Safety     Open Access   (Followers: 1)
Foreign Policy Analysis     Hybrid Journal   (Followers: 24, 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: 33, SJR: 0.118, CiteScore: 0)
French Studies     Hybrid Journal   (Followers: 21, 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: 16, SJR: 2.578, CiteScore: 4)
Geophysical J. Intl.     Hybrid Journal   (Followers: 36, SJR: 1.506, CiteScore: 3)
German History     Hybrid Journal   (Followers: 23, SJR: 0.161, CiteScore: 0)
GigaScience     Open Access   (Followers: 5, SJR: 5.022, CiteScore: 7)
Global Summitry     Hybrid Journal   (Followers: 1)
Glycobiology     Hybrid Journal   (Followers: 13, SJR: 1.493, CiteScore: 3)
Health and Social Work     Hybrid Journal   (Followers: 57, SJR: 0.388, CiteScore: 1)
Health Education Research     Hybrid Journal   (Followers: 16, 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: 34, SJR: 1.278, CiteScore: 1)
Holocaust and Genocide Studies     Hybrid Journal   (Followers: 28, SJR: 0.105, CiteScore: 0)
Human Communication Research     Hybrid Journal   (Followers: 15, SJR: 2.146, CiteScore: 3)
Human Molecular Genetics     Hybrid Journal   (Followers: 9, SJR: 3.555, CiteScore: 5)
Human Reproduction     Hybrid Journal   (Followers: 72, SJR: 2.643, CiteScore: 5)
Human Reproduction Open     Open Access   (Followers: 1)
Human Reproduction Update     Hybrid Journal   (Followers: 20, SJR: 5.317, CiteScore: 10)
Human Rights Law Review     Hybrid Journal   (Followers: 62, SJR: 0.756, CiteScore: 1)
ICES J. of Marine Science: J. du Conseil     Hybrid Journal   (Followers: 55, SJR: 1.591, CiteScore: 3)
ICSID Review : Foreign Investment Law J.     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: 39, SJR: 0.249, CiteScore: 1)
Inflammatory Bowel Diseases     Hybrid Journal   (Followers: 48, SJR: 2.511, CiteScore: 4)
Information and Inference     Free  
Innovation in Aging     Open Access  
Integrative and Comparative Biology     Hybrid Journal   (Followers: 8, SJR: 1.319, CiteScore: 2)
Integrative Biology     Full-text available via subscription   (Followers: 6, SJR: 1.36, CiteScore: 3)
Integrative Organismal Biology     Open Access  
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: 65, SJR: 1.505, CiteScore: 3)
Intl. Data Privacy Law     Hybrid Journal   (Followers: 25)
Intl. Health     Hybrid Journal   (Followers: 6, 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: 36, SJR: 1.348, CiteScore: 2)
Intl. J. of Constitutional Law     Hybrid Journal   (Followers: 64, SJR: 0.601, CiteScore: 1)
Intl. J. of Epidemiology     Hybrid Journal   (Followers: 244, 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: 28, 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: 11, SJR: 1.545, CiteScore: 1)
Intl. J. of Refugee Law     Hybrid Journal   (Followers: 38, 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: 39, 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: 49, SJR: 2.581, CiteScore: 2)
Intl. Studies Review     Hybrid Journal   (Followers: 25, SJR: 1.201, CiteScore: 1)
ISLE: Interdisciplinary Studies in Literature and Environment     Hybrid Journal   (Followers: 2, SJR: 0.15, CiteScore: 0)
ITNOW     Hybrid Journal   (Followers: 1, SJR: 0.103, CiteScore: 0)
J. of African Economies     Hybrid Journal   (Followers: 17, SJR: 0.533, CiteScore: 1)
J. of American History     Hybrid Journal   (Followers: 46, 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: 5, SJR: 0.585, CiteScore: 1)
J. of Biochemistry     Hybrid Journal   (Followers: 41, SJR: 1.226, CiteScore: 2)
J. of Breast Imaging     Full-text available via subscription  
J. of Burn Care & Research     Hybrid Journal   (Followers: 10, SJR: 0.768, CiteScore: 2)

        1 2 3 | Last   [Sort by number of followers]   [Restore default list]

Journal Cover
Publications of the Astronomical Society of Japan
Journal Prestige (SJR): 0.877
Citation Impact (citeScore): 1
Number of Followers: 3  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0004-6264 - ISSN (Online) 2053-051X
Published by Oxford University Press Homepage  [406 journals]
  • AKARI NEP field: Point source catalogs from GALEX and Herschel
           observations and selection of candidate lensed sub-millimeter galaxies
    • Authors: Burgarella D; Mazyed F, Oi N, et al.
      First page: 12
      Abstract: The AKARI Wide North Ecliptic field is one of the most important cosmological fields because it lies in the continuous viewing zones for many space telescopes, e.g., Herschel, HST, and JWST, and it is also a natural high-visibility field from the L2 halo orbit. The field will be also the location of the deep survey for the Euclid mission. Finally, AKARI has made deep mid-IR observations using its nine continuous band filters in the North Ecliptic Pole (NEP) field. We analyzed GALEX and Herschel observations in the NEP field to build catalogs in seven bands: GALEX far UV and near UV, Herschel PACS 100 μm and 250 μm, and SPIRE 250 μm, 350 μm, and 500 μm with quality checks. The SPIRE catalogs are used to identify 61 (6 in a main list and 55 in a supplementary list) candidate lensed galaxies through red 350 μm to 500 μm colors. For the brightest of these candidates with 500 μm flux densities >100 mJy, follow-up observations in millimeter wavelengths have been carried out with the NOEMA interferometer. The high quality of these observations has allowed us to study and compare their morphology beyond that possible using Herschel data alone. We find that the majority of them appear as multiple objects. The redshift distribution of the sources in the main list is found to be in the range 1.5 < $z$ < 2.3. Their IR luminosities confirm that these sources are very likely strongly lensed galaxies.
      PubDate: Sat, 19 Jan 2019 00:00:00 GMT
      DOI: 10.1093/pasj/psy134
      Issue No: Vol. 71, No. 1 (2019)
  • Universal detection of high-temperature emission in X-ray isolated neutron
    • Authors: Yoneyama T; Hayashida K, Nakajima H, et al.
      First page: 17
      Abstract: Strongly magnetized isolated neutron stars (NSs) are categorized into two families, according mainly to their magnetic field strength. Those with a higher magnetic field of 1014–1015 G are called magnetars, characterized by repeated short bursts, and the others are X-ray isolated neutron stars (XINSs) with 1013 G. Both magnetars and XINSs show thermal emission in X-rays, but it has been considered that the thermal spectrum of magnetars can be reproduced with a two-temperature blackbody (2BB), while that of XINSs shows only a single-temperature blackbody (1BB) and the temperature is lower than that of magnetars. On the basis of the magnetic field and temperature, it is often speculated that XINSs may be old and cooled magnetars. Here we report that all seven known XINSs show a high-energy component in addition to the 1BB model. Analyzing all the XMM-Newton data for the XINSs with the highest statistics ever achieved, we find that their X-ray spectra are all reproduced with a 2BB model, similar to magnetars. Their emission radii and temperature ratios are also similar to those of magnetars except for two XINSs, which show significantly smaller radii than the others. The remarkable similarity in the X-ray spectra between XINSs and magnetars suggests that the origins of their emissions are the same. The lower temperature in XINSs can be explained if XINSs are older than magnetars. Therefore, these results are an observational indication that supports the standard hypothesis on the classification of highly magnetized NSs.
      PubDate: Wed, 02 Jan 2019 00:00:00 GMT
      DOI: 10.1093/pasj/psy135
      Issue No: Vol. 71, No. 1 (2019)
  • Property of young massive clusters in a galaxy–galaxy merger remnant
    • Authors: Matsui H; Tanikawa A, Saitoh T.
      First page: 19
      Abstract: We investigate the properties of young massive clusters (YMCs) in a galaxy–galaxy merger remnant by analyzing the data obtained by a gas-rich major merger simulation in Matsui et al. (2012, ApJ, 746, 26). We found that the YMCs are distributed at a few kpc and at ∼10 kpc from the galactic center; in other words, there are two components of their distribution. The former are formed in filamentary and turbulent gas generated at a few kpc from the center as a result of galaxy encounters, and the latter are formed in tidal tails which are far from the center. The YMCs are much less concentrated than galaxy stars. The mass function of the YMCs is dN/dM∝M−2. Most YMCs are formed between the second encounter and the final coalescence phase of the galactic cores, and their formation rate is especially high at the final coalescence phase. Most of them consist of single stellar population in age, but YMCs with multi-stellar populations in age are also formed. The multiple populations are produced by the following process: a YMC captures dense gas, and another generation of stars form within the cluster. There are several YMCs formed in an isolated disk before the encounter of galaxies. These candidates contain stars with various ages by capturing dense gas and forming stars. YMCs in a merger remnant have various orbits, but a large fraction of candidates have circular orbits.
      PubDate: Tue, 08 Jan 2019 00:00:00 GMT
      DOI: 10.1093/pasj/psy139
      Issue No: Vol. 71, No. 1 (2019)
  • Starspots in contact and semi-detached binary systems
    • Authors: Kouzuma S.
      First page: 21
      Abstract: We investigated the statistical properties of both cool and hot starspots in eclipsing binary stars. The starspot and binary parameters for contact and semi-detached systems were collected from literature, determined on the basis of synthetic light-curve analysis. We examined associations between these parameters. It was found that the cool spots in W-type binaries show properties similar to those of sunspots and starspots generated by dynamos, which differs from those of the cool spots in A-type binaries.The properties of hotspots also differ between the W- and A-type samples. From the physical properties of A- and W-type binaries, we infer that mass transfer is a dominant process for forming the hotspots in A-type binaries, and that both mass transfer and magnetic activity can contribute to the formation of the hotspots in W-type binaries. Our results also indicate that the hotspot size in the A-type sample is correlated with the temperature of spotted stars, orbital period, mass ratio, and fill-out factor.
      PubDate: Tue, 08 Jan 2019 00:00:00 GMT
      DOI: 10.1093/pasj/psy140
      Issue No: Vol. 71, No. 1 (2019)
  • Suzaku detection of enigmatic geocoronal solar wind charge exchange event
           associated with coronal mass ejection
    • Authors: Ishi D; Ishikawa K, Numazawa M, et al.
      First page: 23
      Abstract: Suzaku detected an enhancement of the soft X-ray background associated with solar eruptions on 2013 April 14–15. The solar eruptions were accompanied by an M6.5 solar flare and a coronal mass ejection with magnetic flux ropes. The enhanced soft X-ray background showed a slight variation over half a day and then a clear one in a few hours. The former spectrum was composed of oxygen emission lines, while the later one was characterized by a series of emission lines from highly ionized carbon to silicon. The soft X-ray enhancement originated from geocoronal solar wind charge exchange. However, there appeared to be no significant time correlation with the solar wind proton flux measured by the ACE and WIND satellites. From other solar wind signatures, we considered that an interplanetary shock associated with the coronal mass ejection and a turbulent sheath immediately behind the shock compressed the ambient solar wind ions and then resulted in the soft X-ray enhancement. Furthermore, the enriched emission lines were presumed to be due to an unusual set of ion abundances and ionization states within the coronal mass ejection. We found a better time correlation with the solar wind alpha flux rather than the solar wind proton flux. Our results suggest that the solar wind proton flux is not always a good indicator of geocoronal solar wind charge exchange, especially associated with coronal mass ejections. Instead, the solar wind alpha flux should be investigated when such a soft X-ray enhancement is detected in astronomical observations.
      PubDate: Wed, 09 Jan 2019 00:00:00 GMT
      DOI: 10.1093/pasj/psy142
      Issue No: Vol. 71, No. 1 (2019)
  • An image reconstruction method for an X-ray telescope system with an
           angular resolution booster
    • Authors: Morii M; Ikeda S, Maeda Y.
      First page: 24
      Abstract: We propose an image reconstruction method for an X-ray telescope system with an angular resolution booster proposed by Maeda et al. (2018, PASJ, submitted). The system consists of double multi-grid masks in front of an X-ray mirror and an off-focused two-dimensional imager. Because the obtained image is off-focused, an additional image reconstruction process is assumed to be included. Our image reconstruction method is an extension of the traditional Richardson–Lucy algorithm with two regularization terms, one for sparseness and the other for smoothness. Such a combination is desirable for astronomical imaging because astronomical objects have a variety in shape, from point sources to diffuse sources to mixtures of both. The performance of the system is demonstrated with simulated data for point sources and diffuse X-ray sources such as Cas A and the Crab Nebula. The image resolution is improved from a few arcmin of focused image without the booster to a few arcsec with the booster. Through the demonstration, the angular resolution booster with the image reconstruction method is shown to be feasible.
      PubDate: Thu, 10 Jan 2019 00:00:00 GMT
      DOI: 10.1093/pasj/psy143
      Issue No: Vol. 71, No. 1 (2019)
  • AKARI/IRC near-infrared asteroid spectroscopic survey: AcuA-spec
    • Authors: Usui F; Hasegawa S, Ootsubo T, et al.
      First page: 1
      Abstract: Knowledge of water in the solar system is important for the understanding of a wide range of evolutionary processes and the thermal history of the solar system. To explore the existence of water in the solar system, it is indispensable to investigate hydrated minerals and/or water ice on asteroids. These water-related materials show absorption features in the 3 μm band (wavelengths from 2.7 to 3.1 μm). We conducted a spectroscopic survey of asteroids in the 3 μm band using the Infrared Camera (IRC) on board the Japanese infrared satellite AKARI. In the warm mission period of AKARI, 147 pointed observations were performed for 66 asteroids in the grism mode for wavelengths from 2.5 to 5 μm. According to these observations, most C-complex asteroids have clear absorption features (>10% with respect to the continuum) related to hydrated minerals at a peak wavelength of approximately 2.75 μm, while S-complex asteroids have no significant features in this wavelength range. The present data are released to the public as the Asteroid Catalog using AKARI Spectroscopic Observations (AcuA-spec).
      PubDate: Mon, 17 Dec 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy125
      Issue No: Vol. 71, No. 1 (2018)
  • Revised wavelength and spectral response calibrations for AKARI
           near-infrared grism spectroscopy: Post-cryogenic phase
    • Authors: Baba S; Nakagawa T, Usui F, et al.
      First page: 2
      Abstract: We present a new calibration for the second-order light contamination in the near-infrared grism spectroscopy with the Infrared Camera aboard AKARI, specifically for the post-cryogenic phase of the satellite (Phase 3). Following our previous work on the cryogenic phase (Phases 1 and 2), the wavelength and spectral response calibrations were revised. Unlike Phases 1 and 2, during Phase 3 the temperature of the instrument was not stable and gradually increased from 40 to 47 K. To assess the effect of the temperature increase, we divided Phase 3 into three sub-phases and performed the calibrations separately. As in Phases 1 and 2, we confirmed that there was contamination due to the wavelength dependence of the refractive index of the grism material in every sub-phase. The wavelength calibration curves for the three sub-phases coincided with each other and did not show any significant temperature dependence. The response decreased with temperature by ∼10% from the beginning to the end of Phase 3. We approximated the temperature dependence of the response at a linear relation and derived a correction factor as a function of temperature. The relative fraction of the second-order light contamination to the first-order light was found to be 25% smaller than that in Phases 1 and 2.
      PubDate: Fri, 30 Nov 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy131
      Issue No: Vol. 71, No. 1 (2018)
  • AKARI mid-infrared slit-less spectroscopic catalogue
    • Authors: Yamagishi M; Yamamura I, Mizuki T, et al.
      First page: 3
      Abstract: AKARI/IRC is capable of conducting slit-less spectroscopy in the mid-infrared (5–13 μm) over a 10΄ × 10΄ area with a spectral resolution of 50, which is suitable for serendipitous surveys. The data reduction is, however, rather complicated by the confusion of nearby sources after dispersing the spectra. To achieve efficient and reliable data reduction, we first compiled a point-source list from the reference image in each field of view and checked the overlaps of the spectra using their relative positions and fluxes. Applying this procedure to 886 mid-infrared slit-less spectroscopic data taken in the cryogenic phase, we obtained 862 mid-infrared spectra from 604 individual non-overlapping sources brighter than 1.5 mJy. We find a variety of objects in the spectroscopic catalogue, ranging from stars to galaxies. We also obtained a by-product catalogue of 9 μm point sources containing 42837 objects brighter than 0.3 mJy. The spectroscopic and point-source catalogues are available online.
      PubDate: Wed, 19 Dec 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy132
      Issue No: Vol. 71, No. 1 (2018)
  • AKARI mission program: Excavating Mass Loss History in extended dust
           shells of Evolved Stars (MLHES). I. Far-IR photometry†
    • Authors: Ueta T; Torres A, Izumiura H, et al.
      First page: 4
      Abstract: We performed a far-IR imaging survey of the circumstellar dust shells of 144 evolved stars as a mission program of the AKARI infrared astronomical satellite using the Far-Infrared Surveyor (FIS) instrument. With this survey, we deliver far-IR surface brightness distributions of roughly 10′ × 40′ or 10′ × 20′ areas of the sky around the target evolved stars in the four FIS bands at 65, 90, 140, and 160 μm. Our objectives are to characterize the far-IR surface brightness distributions of the cold dust component in the circumstellar dust shells, from which we derive the amount of cold dust grains as low as 20 K and empirically establish the early mass loss history. In this first installment of the series, we introduce the project and its aims, describe the observations, data reduction, and surface brightness correction process, and present the entire data set along with the results of integrated photometry measurements (i.e., the central source and circumstellar dust shell together). We find that: (1) far-IR emission is detected from all but one object at the spatial resolution about 30′–50′ in the corresponding bands; (2) roughly 60%–70% of the target sources show some extension; (3) previously unresolved nearby objects in the far IR are now resolved around 28 target sources; (4) the results of photometry measurements are reasonable with respect to the entries in the AKARI/FIS Bright Source Catalogue, despite the fact that the targets were assumed to be point sources when catalogue flux densities were computed; and (5) an IR two-color diagram would place the target sources in a roughly linear distribution that may correlate with the age of the circumstellar dust shell and can potentially be used to identify which targets are more extended than others.
      PubDate: Thu, 06 Dec 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy130
      Issue No: Vol. 71, No. 1 (2018)
  • On surface brightness and flux calibration for point and compact extended
           sources in the AKARI Far-IR All-Sky Survey (AFASS) maps
    • Authors: Ueta T; Szczerba R, Fullard A, et al.
      First page: 5
      Abstract: The AKARI infrared astronomical satellite produced all-sky survey (AFASS) maps in the far-infrared at roughly arcminute spatial resolution, enabling us to investigate the whole sky in the far-infrared for objects having surface brightnesses greater than a few to a couple of dozen MJy sr−1. While the AFASS maps are absolutely calibrated against large-scale diffuse emission, it was uncertain whether or not an additional flux correction for point sources was necessary. Here, we verify that calibration for point-source photometry in the AFASS maps is proper. With the aperture correction method based on the empirical point spread function templates derived directly from the AFASS maps, fluxes in the AKARI bright source catalogue (BSC) are reproduced. The AKARI BSC fluxes are also satisfactorily recovered with the 1 σ aperture, which is the empirical equivalent of an infinite aperture. These results confirm that in the AFASS maps far-infrared photometry can be properly performed by using the aperture correction method for point sources and by summing all pixel values within an appropriately defined aperture of the intended target (i.e., the aperture photometry method) for extended sources.
      PubDate: Thu, 13 Sep 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy097
      Issue No: Vol. 71, No. 1 (2018)
  • A systematic study of Galactic infrared bubbles along the Galactic plane
           with AKARI and Herschel
    • Authors: Hanaoka M; Kaneda H, Suzuki T, et al.
      First page: 6
      Abstract: Galactic infrared (IR) bubbles, which have shell-like structures in the mid-IR wavelengths, are known to contain massive stars near their centers. Infrared bubbles in inner Galactic regions ( l ≤ 65°, b ≤ 1°) have so far been studied well to understand the massive star formation mechanisms. In this study, we expand the research area to the whole Galactic plane (0° ≤ l < 360°, b ≤ 5°), using the AKARI all-sky survey data. We limit our study to large bubbles with angular radii of >1′ to reliably identify and characterize them. For the 247 IR bubbles in total, we derived the radii and the covering fractions of the shells, based on the method developed by Y. Hattori et al. (2016, PASJ, 68, 37). We also created their spectral energy distributions, using the AKARI and Herschel photometric data, and decomposed them with a dust model to obtain the total IR luminosity and the luminosity of each dust component, i.e., polycyclic aromatic hydrocarbons (PAHs), warm dust, and cold dust. As a result, we find that there are systematic differences in the IR properties of the bubbles between the inner and outer Galactic regions. The total IR luminosities are lower in outer Galactic regions, while there is no systematic difference in the range of the shell radii between inner and outer Galactic regions. More IR bubbles tend to be observed as broken bubbles rather than closed ones and the fractional luminosities of the PAH emission are significantly higher in outer Galactic regions. We discuss the implications of these results for the massive stars and the interstellar environments associated with the Galactic IR bubbles.
      PubDate: Thu, 29 Nov 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy126
      Issue No: Vol. 71, No. 1 (2018)
  • AKARI and IRAS: From beam corrections to SEDs
    • Authors: Clements D; Rowan-Robinson M, Pearson C, et al.
      First page: 7
      Abstract: There is significant scientific value to be gained from combining AKARI fluxes with data at other far-infrared (IR) wavelengths from the Infrared Astronomical Satellite (IRAS) and Herschel missions. To be able to do this we must ensure that there are no systematic differences between the data sets that need to be corrected before the fluxes are compatible with each other. One such systematic effect identified in the Bright Source Catalog version 1 (BSCv1) data is the issue of beam corrections. We determine these for the BSC version 2 (BSCv2) data by correlating ratios of appropriate IRAS and AKARI bands with the difference in 2 Micron All Sky Survey (2MASS) J-band extended and point source magnitudes for sources cross-matched between the IRAS Faint Source Catalog (FSC), AKARI BSCv2 and 2MASS catalogs. We find significant correlations (p ≪ 10 −13) indicating that beam corrections are necessary in the 65 and 90 μm bands. We then use these corrected fluxes to supplement existing data in spectral energy distribution (SED) fits for ultraluminous infrared galaxies (ULIRGs) in the Herschel ULIRG Survey (HERUS). The addition of AKARI fluxes makes little difference to the results of simple (T, β) fits to the SEDs of these sources, though there is a general decrease in reduced χ2 values. The utility of the extra AKARI data, however, is in allowing physically more realistic SED models with more parameters to be fitted to the data. We also extend our analysis of beam correction issues in the AKARI data by examining the Herschel Reference Sample (HRS) galaxies, which have Herschel photometry from 100 to 500 μm and which are more spatially extended than the HERUS ULIRGs. 34 of the HRS sources have good Herschel SEDs and matching data from AKARI. This investigation finds that our simple 2MASS-based beam correction scheme is inadequate for these larger and more complex sources. There are also indications that additional beam corrections at 140 and 160 μm are needed for these sources, extended on scales >1′.
      PubDate: Wed, 10 Oct 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy099
      Issue No: Vol. 71, No. 1 (2018)
  • On the different levels of dust attenuation to nebular and stellar light
           in star-forming galaxies
    • Authors: Koyama Y; Shimakawa R, Yamamura I, et al.
      First page: 8
      Abstract: As a science verification study of the newly released AKARI/FIS Faint Source Catalog ver. 1, this paper discusses the different levels of dust attenuation toward stellar light and nebular emission lines within local star-forming galaxies at 0.02 < $z$ < 0.10. By constructing an updated version of the AKARI–SDSS–GALEX matched galaxy catalog (with >2000 sources), we compare the dust attenuation levels toward stellar light (from the LIR/LUV ratio) and nebular emission lines (from the Hα/Hβ ratio). We find that there is a clear trend that more massive galaxies tend to have higher “extra” attenuation toward nebular regions, while galaxies with higher specific star formation rates tend to have lower extra attenuation. We also confirm these trends by using the WISE mid-infrared photometry with a significantly large sample size of the WISE–SDSS–GALEX galaxies (>50000 sources). Finally, we study how the levels of extra attenuation toward nebular regions change across the SFR–M⋆ plane. We find that, even at a fixed stellar mass, galaxies located below the main sequence tend to have higher levels of extra attenuation toward nebular regions, suggesting a change in dust geometry within the galaxies across the star-forming main sequence during the course of the star formation quenching process.
      PubDate: Thu, 11 Oct 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy113
      Issue No: Vol. 71, No. 1 (2018)
  • Far-infrared dust properties of highly dust-obscured active galactic
           nuclei from the AKARI and WISE all-sky surveys
    • Authors: Lam A; Malkan M, Wright E.
      First page: 9
      Abstract: The combination of the AKARI and WISE infrared all-sky surveys provides a unique opportunity to identify and characterize the most highly dust-obscured active galactic nuclei (AGNs) in the universe. Dust-obscured AGNs are not easily detectable and are potentially underrepresented in extragalactic surveys due to their high optical extinction, but are readily found in the WISE catalog due to their extremely red mid-infrared (IR) colors. Combining these surveys with photometry from Pan-STARRS and Herschel, we use spectral energy distribution (SED) modeling to characterize the extinction and dust properties of these AGNs. From mid-IR WISE colors we are able to compute bolometric corrections to AGN luminosities. Using AKARI’s far-IR wavelength photometry and broadband AGN/galaxy spectral templates we estimate AGN dust mass and temperature using simple analytic models with three or four parameters. Even without spectroscopic data we can determine a number of AGN dust properties only using SED analysis. These methods, combined with the abundance of archival photometric data publicly available, will be valuable for large-scale studies of dusty, IR-luminous AGNs.
      PubDate: Wed, 01 Aug 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy081
      Issue No: Vol. 71, No. 1 (2018)
  • Galactic foreground of gamma-ray bursts from AKARI Far-Infrared Surveyor
    • Authors: Toth L; Doi Y, Zahorecz S, et al.
      First page: 10
      Abstract: We demonstrate the use of the AKARI FIS All-Sky Survey maps in the study of extragalactic objects. A quick but reliable estimate of the Galactic foreground is essential for extragalactic research in general. We explored the galactic foreground and calculated hydrogen column densities using AKARI FIS and other recent all-sky survey data, and compared our results to former estimates. Our AKARI-FIS-based foreground values were then used toward gamma-ray burst (GRB) sources as input for X-ray afterglow spectrum fitting. From those fits the intrinsic column densities at the GRB sources were derived. The high-angular-resolution AKARI-FIS-based Galactic foreground hydrogen column densities are statistically very similar, but for most of the tested directions somewhat lower than previous estimates based on low-resolution data. This is due to the low filling factor of high-density enhancements in all galactic latitudes. Accordingly, our AKARI-FIS-based new intrinsic hydrogen column densities are usually higher or similar compared to the values calculated based, e.g., on the low-resolution Leiden/Argentine/Bonn survey data and listed in the Leicester database. The variation, however, is typically smaller than the error of the estimate from the fits of the X-ray afterglow spectra. There are a number of directions where the improvement of the foreground estimates resulted in an overestimate of magnitude or higher increment of the derived intrinsic hydrogen column densities. We concluded that most of the GRBs with formerly extremely low intrinsic hydrogen column densities are in fact normal, but we confirmed that GRB050233 is indeed a non-enveloped long GRB.
      PubDate: Thu, 22 Nov 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy123
      Issue No: Vol. 71, No. 1 (2018)
  • Characteristics of mid-infrared PAH emission from star-forming galaxies
           selected at 250 μm in the North Ecliptic Pole field
    • Authors: Kim S; Jeong W, Goto T, et al.
      First page: 11
      Abstract: Evolutionary properties of infrared (IR) luminous galaxies are important keys to understand dust-obscured star formation history and galaxy evolution. Based on near- to mid-IR imaging with nine continuous filters of the AKARI space telescope, we present the characteristics of dusty star-forming (SF) galaxies showing polycyclic aromatic hydrocarbon (PAH) features observed by the North Ecliptic Pole (NEP) wide field survey of AKARI and Herschel. All the sample galaxies from the AKARI/NEP-Wide data are selected based both on the Herschel/SPIRE 250 μm detection and optical spectroscopic redshift data. The physical modeling of spectral energy distribution (SED) using all available data points from u* to sub-mm 500 μm band, including WISE and PACS data where available, takes unique advantages of the continuous near- to mid-IR coverage, the reliable constraint on the far-IR peak, and spectroscopically determined accurate redshifts, as well as the energy balance principle by MAGPHYS. This enables us to derive physically meaningful and accurate total infrared luminosity and 8 μm (or PAH) luminosity consistently. Our sample galaxies are in the redshift range $z$ < 1, and the majority of them appear to be normal SF/spiral populations showing PAH features near 8 μm. These SF galaxies showing PAHs in the mid-IR include various types, from quiescent to starbursts. Some of our sample show shortage of 8 μm luminosity compared to the total IR luminosity and this PAH deficit gets severe in more-luminous IR galaxies, suggesting PAH molecules in these galaxies are destroyed by a strong radiation field from the SF region or a large amount of cold dust in the interstellar medium. The specific SFR of our sample shows mass-dependent time evolution which is consistent with a downsizing evolutionary pattern.
      PubDate: Tue, 11 Dec 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy121
      Issue No: Vol. 71, No. 1 (2018)
  • The Herschel-PACS North Ecliptic Pole Survey
    • Authors: Pearson C; Barrufet L, Campos Varillas M, et al.
      First page: 13
      Abstract: A detailed analysis of Herschel/Photoconductor Array Camera and Spectrometer (PACS) observations at the North Ecliptic Pole is presented. High-quality maps, covering an area of 0.44 deg2, are produced and then used to derive potential candidate source lists. A rigorous quality-control pipeline has been used to create final legacy catalogues in the PACS Green 100 μm and Red 160 μm bands, containing 1384 and 630 sources respectively. These catalogues reach to more than twice the depth of the current archival Herschel/PACS Point Source Catalogue, detecting 400 and 270 more sources in the short- and long-wavelength bands, respectively. Galaxy source counts are constructed that extend down to flux densities of 6 mJy and 19 mJy (50% completeness) in the Green 100 μm and Red 160 μm bands, respectively. These source counts are consistent with previously published PACS number counts in other fields across the sky. The source counts are then compared with a galaxy evolution model which identifies a population of luminous infrared galaxies as responsible for the bulk of the galaxy evolution over the flux range (5–100 mJy) spanned by the observed counts, contributing approximate fractions of 50% and 60% to the cosmic infrared background at 100 μm and 160 μm, respectively.
      PubDate: Wed, 10 Oct 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy107
      Issue No: Vol. 71, No. 1 (2018)
  • Solar jet-like features rooted in flare ribbons
    • Authors: Li X; Zhang J, Yang S, et al.
      First page: 14
      Abstract: Employing the high spatio-temporal Interface Region Imaging Spectrograph 1330 Å observations, we investigated the jet-like features that occurred during the X8.2 class flare in NOAA active region (AR) 12673 on 2017 September 10. These jet-like features were rooted in the flare ribbons. We examined 15 features, and the mean values of the lifetimes, projected widths, lengths, and velocities of these features were 87 s, 890 km, 2.7 Mm, and 70 km s−1, respectively. We also observed many jet-like features which happened during the X1.0 class flare on 2014 October 25. We studied the spectra at the base of a jet-like feature during its development. The Fe xxi 1354.08 Å line in the corona displays blueshift, while the Si iv 1402.77 Å line in the transition region exhibits redshift, which indicates the chromospheric evaporation. This is the first time that the jet-like features are reported to be rooted in the flare ribbons, and we suggest that these jet-like features were driven by the mechanism of chromospheric evaporation.
      PubDate: Wed, 28 Nov 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy128
      Issue No: Vol. 71, No. 1 (2018)
  • A NuSTAR study of the 55 ks hard X-ray pulse-phase modulation in the
           magnetar 4U 0142+61
    • Authors: Makishima K; Murakami H, Enoto T, et al.
      First page: 15
      Abstract: Archival NuSTAR data of the magnetar 4U 0142+61, acquired in 2014 March for a total time span of 258 ks, were analyzed. This is to reconfirm the 55 ks modulation in the hard X-ray pulse phases of this source, found with a Suzaku observation in 2009 (Makishima et al., 2014, Phys. Rev. Lett., 112, 171102). Indeed, the 10–70 keV X-ray pulsation, detected with NuSTAR at 8.68917 s, was found to be also phase-modulated (at >98% confidence) at the same ∼55 ks period, or half that value. Furthermore, a brief analysis of another Suzaku data set of 4U 0142+61, acquired in 2013, reconfirmed the same 55 ks phase modulation in the 15–40 keV pulses. Thus, the hard X-ray pulse-phase modulation was detected with Suzaku (in 2009 and 2013) and NuSTAR (in 2014) at a consistent period. However, the modulation amplitude varied significantly; A ∼ 0.7 s with Suzaku (in 2009), A ∼ 1.2 s with Suzaku (in 2013), and A ∼ 0.17 s with NuSTAR. In addition, the phase modulation properties detected with NuSTAR differed considerably between the first 1/3 and the latter 2/3 of the observation. In energies below 10 keV, the pulse-phase modulation was not detected with either Suzaku or NuSTAR. These results reinforce the view of Makishima et al. (2014, Phys. Rev. Lett., 112, 171102); the neutron star in 4U 0142+61 keeps free precession, under a slight axial deformation due probably to ultra-high toroidal magnetic fields of ∼1016 G. The wobbling angle of precession should remain constant, but the pulse-phase modulation amplitude varies on time scales of months to years, presumably as asymmetry of the hard X-ray emission pattern around the star’s axis changes.
      PubDate: Wed, 28 Nov 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy129
      Issue No: Vol. 71, No. 1 (2018)
  • Annual parallax measurements of a semi-regular variable star SV Pegasus
           with VERA
    • Authors: Sudou H; Omodaka T, Murakami K, et al.
      First page: 16
      Abstract: Many studies have shown that there are clear sequences in the period–luminosity relationship (PLR) for Mira variables and semi-regular variables (SRVs) in the Large Magellanic Cloud (LMC). To investigate the PLR for SRVs in our galaxy, we examined the annual parallax measurement and conducted K΄-band photometric monitoring of an SRV star SV Pegasus (SV Peg). We measured the position change of the associated H2O maser spots by phase-referencing Very Long Baseline Interferometry (VLBI) observations with VERA at 22 GHz, spanning approximately 3 yr, and detected an annual parallax of π = 3.00 ± 0.06 mas, corresponding to a distance of D = 333 ± 7 pc. This result is in good agreement with the Hipparcos parallax and improves the accuracy of the distance from 35% to 2%. However, the Gaia DR2 catalog gave a parallax of π = 1.12 ± 0.28 mas for SV Peg. This indicates that the Gaia result might be blurred by the effect of the stellar size because the estimated stellar radius was ∼5 mas, which is comparable to the parallax. We obtained a K΄-band mean magnitude of $m_{K^{\prime }} = -0.48\:$mag and a period of P = 177 d from our photometric monitoring with a 1 m telescope. Using the trigonometric distance, we derived an absolute magnitude of $M_{K^{\prime }}=-8.09 \pm 0.05\:$mag. This result shows that the position of SV Peg in the PLR falls on the C’ sequence found in the PLR in the LMC, which is similar to other SRVs in our galaxy.
      PubDate: Sat, 15 Dec 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy133
      Issue No: Vol. 71, No. 1 (2018)
  • Hermite integrator for high-order mesh-free schemes
    • Authors: Yamamoto S; Makino J.
      First page: 18
      Abstract: In most mesh-free methods, the calculation of interactions between sample points or “particles” is the most time-consuming. When we use mesh-free methods with high spatial orders, the order of the time integration should also be high. If we use usual Runge–Kutta schemes, we need to perform the interaction calculation multiple times per time step. One way to reduce the number of interaction calculations is to use Hermite schemes, which use the time derivatives of the right-hand side of differential equations, since Hermite schemes require a smaller number of interaction calculations than Runge–Kutta schemes do to achieve the same order. In this paper, we construct a Hermite scheme for a mesh-free method with high spatial orders. We performed several numerical tests with fourth-order Hermite schemes and Runge–Kutta schemes. We found that, for both Hermite and Runge–Kutta schemes, the overall error is determined by the error of spatial derivatives, for time steps smaller than the stability limit. The calculation cost at the time-step size of the stability limit is smaller for Hermite schemes. Therefore, we conclude that Hermite schemes are more efficient than Runge–Kutta schemes and thus useful for high-order mesh-free methods for Lagrangian hydrodynamics.
      PubDate: Wed, 12 Dec 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy137
      Issue No: Vol. 71, No. 1 (2018)
  • Three Z Camelopardalis-type dwarf novae exhibiting IW Andromedae-type
    • Authors: Kato T.
      First page: 20
      Abstract: I found that V507 Cyg, IM Eri, and FY Vul are Z Cam-type dwarf novae and they showed sequences of standstill terminated by brightening, in contrast to fading as ordinary Z Cam stars do, followed by damping oscillation. These sequences are characteristic to IW And-type objects (also known as anomalous Z Cam stars). New additions to the IW And-type objects suggest that the IW And-type phenomenon is more prevalent among Z Cam stars. I suspect that the regularity of the pattern of the IW And-type phenomenon suggests a previously unknown type of limit-cycle oscillation, and I suggest that the standstill in these objects is somehow maintained in the inner part of the disk and that the thermal instability starting from the outer part of the disk terminates the standstill to complete the cycle.
      PubDate: Sat, 22 Dec 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy138
      Issue No: Vol. 71, No. 1 (2018)
  • Third-nearest WZ Sge-Type dwarf nova candidate ASASSN-14dx classified on
           the basis of Gaia Data Release 2
    • Authors: Isogai K; Kato T, Imada A, et al.
      First page: 22
      Abstract: ASASSN-14dx showed an extraordinary outburst whose features are a small outburst amplitude (∼2.3 mag) and long duration (>4 yr). Because we found a long observational gap of 123 d before the outburst detection, we propose that the main outburst plateau was missed and that this outburst is just a “fading tail” often seen after the WZ Sge-type super-outbursts. In order to distinguish between WZ Sge and SU UMa-type dwarf novae (DNe), we investigated Gaia Data Release 2 (DR2) statistically. We applied a logistic regression model and succeeded in classifying by using absolute Gaia magnitudes MG and Gaia colors GBP–GRP. Our new classifier also suggests that ASASSN-14dx is the best candidate of a WZ Sge-type DN. We estimated distances from the Earth of known WZ Sge stars by using Gaia DR2 parallaxes. The result indicates that ASASSN-14dx is the third-nearest WZ Sge star (next to WZ Sge and V455 And), and hence the object can show the third-brightest WZ Sge-type super-outburst whose maximum is V = 8–9 mag.
      PubDate: Sat, 22 Dec 2018 00:00:00 GMT
      DOI: 10.1093/pasj/psy141
      Issue No: Vol. 71, No. 1 (2018)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
Home (Search)
Subjects A-Z
Publishers A-Z
Your IP address:
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-