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Publisher: Springer-Verlag (Total: 2352 journals)

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Showing 1 - 200 of 2351 Journals sorted alphabetically
3D Research     Hybrid Journal   (Followers: 20, SJR: 0.214, h-index: 10)
4OR: A Quarterly J. of Operations Research     Hybrid Journal   (Followers: 10, SJR: 1.073, h-index: 25)
AAPS J.     Hybrid Journal   (Followers: 21, SJR: 1.192, h-index: 74)
AAPS PharmSciTech     Hybrid Journal   (Followers: 7, SJR: 0.718, h-index: 54)
Abdominal Imaging     Hybrid Journal   (Followers: 14, SJR: 0.723, h-index: 60)
Abhandlungen aus dem Mathematischen Seminar der Universitat Hamburg     Hybrid Journal   (Followers: 3, SJR: 0.447, h-index: 12)
Academic Psychiatry     Full-text available via subscription   (Followers: 23, SJR: 0.492, h-index: 32)
Academic Questions     Hybrid Journal   (Followers: 8, SJR: 0.135, h-index: 6)
Accreditation and Quality Assurance: J. for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26, SJR: 0.378, h-index: 30)
Acoustical Physics     Hybrid Journal   (Followers: 11, SJR: 0.355, h-index: 20)
Acoustics Australia     Hybrid Journal  
Acta Analytica     Hybrid Journal   (Followers: 7, SJR: 0.387, h-index: 6)
Acta Applicandae Mathematicae     Hybrid Journal   (Followers: 1, SJR: 0.624, h-index: 34)
Acta Biotheoretica     Hybrid Journal   (Followers: 4, SJR: 0.419, h-index: 25)
Acta Diabetologica     Hybrid Journal   (Followers: 17, SJR: 1.318, h-index: 46)
Acta Endoscopica     Hybrid Journal   (Followers: 1, SJR: 0.113, h-index: 8)
acta ethologica     Hybrid Journal   (Followers: 4, SJR: 0.465, h-index: 23)
Acta Geochimica     Hybrid Journal   (Followers: 6)
Acta Geodaetica et Geophysica     Hybrid Journal   (Followers: 2, SJR: 0.294, h-index: 13)
Acta Geotechnica     Hybrid Journal   (Followers: 7, SJR: 1.818, h-index: 22)
Acta Informatica     Hybrid Journal   (Followers: 5, SJR: 0.524, h-index: 32)
Acta Mathematica     Hybrid Journal   (Followers: 11, SJR: 8.021, h-index: 47)
Acta Mathematica Hungarica     Hybrid Journal   (Followers: 2, SJR: 0.53, h-index: 29)
Acta Mathematica Sinica, English Series     Hybrid Journal   (Followers: 6, SJR: 0.406, h-index: 30)
Acta Mathematica Vietnamica     Hybrid Journal   (SJR: 0.451, h-index: 5)
Acta Mathematicae Applicatae Sinica, English Series     Hybrid Journal   (SJR: 0.22, h-index: 20)
Acta Mechanica     Hybrid Journal   (Followers: 21, SJR: 0.898, h-index: 52)
Acta Mechanica Sinica     Hybrid Journal   (Followers: 5, SJR: 0.426, h-index: 29)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 6, SJR: 0.525, h-index: 18)
Acta Meteorologica Sinica     Hybrid Journal   (Followers: 3, SJR: 0.524, h-index: 14)
Acta Neurochirurgica     Hybrid Journal   (Followers: 6, SJR: 0.833, h-index: 73)
Acta Neurologica Belgica     Hybrid Journal   (Followers: 1, SJR: 0.348, h-index: 27)
Acta Neuropathologica     Hybrid Journal   (Followers: 5, SJR: 6.61, h-index: 117)
Acta Oceanologica Sinica     Hybrid Journal   (Followers: 3, SJR: 0.295, h-index: 17)
Acta Parasitologica     Hybrid Journal   (Followers: 10, SJR: 0.581, h-index: 28)
Acta Physiologiae Plantarum     Hybrid Journal   (Followers: 2, SJR: 0.551, h-index: 39)
Acta Politica     Hybrid Journal   (Followers: 13, SJR: 0.658, h-index: 20)
Activitas Nervosa Superior     Hybrid Journal  
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5, SJR: 0.103, h-index: 4)
ADHD Attention Deficit and Hyperactivity Disorders     Hybrid Journal   (Followers: 22, SJR: 0.871, h-index: 15)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 8)
Administration and Policy in Mental Health and Mental Health Services Research     Partially Free   (Followers: 15, SJR: 0.795, h-index: 40)
Adsorption     Hybrid Journal   (Followers: 4, SJR: 0.774, h-index: 52)
Advances in Applied Clifford Algebras     Hybrid Journal   (Followers: 3, SJR: 0.319, h-index: 15)
Advances in Atmospheric Sciences     Hybrid Journal   (Followers: 36, SJR: 0.959, h-index: 44)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 18, SJR: 1.255, h-index: 44)
Advances in Contraception     Hybrid Journal   (Followers: 3)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 51, SJR: 1.113, h-index: 14)
Advances in Gerontology     Partially Free   (Followers: 8, SJR: 0.141, h-index: 3)
Advances in Health Sciences Education     Hybrid Journal   (Followers: 26, SJR: 1.397, h-index: 42)
Advances in Manufacturing     Hybrid Journal   (Followers: 3, SJR: 0.2, h-index: 4)
Advances in Polymer Science     Hybrid Journal   (Followers: 43, SJR: 0.637, h-index: 89)
Advances in Therapy     Hybrid Journal   (Followers: 5, SJR: 0.79, h-index: 44)
Aegean Review of the Law of the Sea and Maritime Law     Hybrid Journal   (Followers: 6)
Aequationes Mathematicae     Hybrid Journal   (Followers: 2, SJR: 0.882, h-index: 23)
Aerobiologia     Hybrid Journal   (Followers: 2, SJR: 0.511, h-index: 36)
Aesthetic Plastic Surgery     Hybrid Journal   (Followers: 9, SJR: 0.821, h-index: 49)
African Archaeological Review     Hybrid Journal   (Followers: 16, SJR: 0.612, h-index: 24)
Afrika Matematika     Hybrid Journal   (Followers: 1, SJR: 0.248, h-index: 6)
AGE     Hybrid Journal   (Followers: 7, SJR: 1.358, h-index: 33)
Ageing Intl.     Hybrid Journal   (Followers: 7, SJR: 0.337, h-index: 10)
Aggiornamenti CIO     Hybrid Journal   (Followers: 1)
Aging Clinical and Experimental Research     Hybrid Journal   (Followers: 3, SJR: 0.529, h-index: 55)
Agricultural Research     Hybrid Journal   (Followers: 4)
Agriculture and Human Values     Hybrid Journal   (Followers: 14, SJR: 1.197, h-index: 49)
Agroforestry Systems     Hybrid Journal   (Followers: 19, SJR: 0.64, h-index: 56)
Agronomy for Sustainable Development     Hybrid Journal   (Followers: 11, SJR: 1.732, h-index: 59)
AI & Society     Hybrid Journal   (Followers: 6, SJR: 0.171, h-index: 19)
AIDS and Behavior     Hybrid Journal   (Followers: 13, SJR: 2.006, h-index: 71)
Air Quality, Atmosphere & Health     Hybrid Journal   (Followers: 4, SJR: 0.706, h-index: 19)
Akupunktur & Aurikulomedizin     Full-text available via subscription   (Followers: 1)
Algebra and Logic     Hybrid Journal   (Followers: 5, SJR: 0.566, h-index: 18)
Algebra Universalis     Hybrid Journal   (Followers: 2, SJR: 0.388, h-index: 22)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1, SJR: 0.868, h-index: 20)
Algorithmica     Hybrid Journal   (Followers: 8, SJR: 0.898, h-index: 56)
Allergo J.     Full-text available via subscription   (Followers: 1, SJR: 0.183, h-index: 20)
Allergo J. Intl.     Hybrid Journal   (Followers: 2)
Alpine Botany     Hybrid Journal   (Followers: 5, SJR: 0.729, h-index: 20)
ALTEX : Alternatives to Animal Experimentation     Open Access   (Followers: 3, SJR: 1.392, h-index: 32)
AMBIO     Hybrid Journal   (Followers: 11, SJR: 1.094, h-index: 87)
American J. of Cardiovascular Drugs     Hybrid Journal   (Followers: 16, SJR: 0.864, h-index: 39)
American J. of Community Psychology     Hybrid Journal   (Followers: 26, SJR: 1.237, h-index: 83)
American J. of Criminal Justice     Hybrid Journal   (Followers: 8, SJR: 0.634, h-index: 13)
American J. of Cultural Sociology     Hybrid Journal   (Followers: 15, SJR: 0.283, h-index: 3)
American J. of Dance Therapy     Hybrid Journal   (Followers: 4, SJR: 0.175, h-index: 13)
American J. of Potato Research     Hybrid Journal   (Followers: 2, SJR: 0.558, h-index: 35)
American J. of Psychoanalysis     Hybrid Journal   (Followers: 20, SJR: 0.293, h-index: 13)
American Sociologist     Hybrid Journal   (Followers: 12, SJR: 0.18, h-index: 13)
Amino Acids     Hybrid Journal   (Followers: 8, SJR: 1.362, h-index: 83)
AMS Review     Partially Free   (Followers: 4)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 7, SJR: 0.21, h-index: 37)
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 4, SJR: 0.665, h-index: 7)
Analysis in Theory and Applications     Hybrid Journal   (Followers: 1)
Analysis of Verbal Behavior     Hybrid Journal   (Followers: 5)
Analytical and Bioanalytical Chemistry     Hybrid Journal   (Followers: 32, SJR: 1.096, h-index: 123)
Anatomical Science Intl.     Hybrid Journal   (Followers: 2, SJR: 0.301, h-index: 26)
Angewandte Schmerztherapie und Palliativmedizin     Hybrid Journal  
Angiogenesis     Hybrid Journal   (Followers: 3, SJR: 2.212, h-index: 69)
Animal Cognition     Hybrid Journal   (Followers: 18, SJR: 1.122, h-index: 55)
Annales françaises de médecine d'urgence     Hybrid Journal   (Followers: 1, SJR: 0.156, h-index: 4)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3, SJR: 1.377, h-index: 32)
Annales mathématiques du Québec     Hybrid Journal   (Followers: 4)
Annali dell'Universita di Ferrara     Hybrid Journal   (SJR: 0.504, h-index: 14)
Annali di Matematica Pura ed Applicata     Hybrid Journal   (Followers: 1, SJR: 1.167, h-index: 26)
Annals of Behavioral Medicine     Hybrid Journal   (Followers: 14, SJR: 2.112, h-index: 98)
Annals of Biomedical Engineering     Hybrid Journal   (Followers: 18, SJR: 1.182, h-index: 94)
Annals of Combinatorics     Hybrid Journal   (Followers: 3, SJR: 0.849, h-index: 15)
Annals of Data Science     Hybrid Journal   (Followers: 11)
Annals of Dyslexia     Hybrid Journal   (Followers: 10, SJR: 0.857, h-index: 40)
Annals of Finance     Hybrid Journal   (Followers: 29, SJR: 0.686, h-index: 14)
Annals of Forest Science     Hybrid Journal   (Followers: 6, SJR: 0.929, h-index: 57)
Annals of Global Analysis and Geometry     Hybrid Journal   (Followers: 1, SJR: 1.136, h-index: 23)
Annals of Hematology     Hybrid Journal   (Followers: 16, SJR: 1.117, h-index: 62)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 12, SJR: 0.593, h-index: 42)
Annals of Microbiology     Hybrid Journal   (Followers: 10, SJR: 0.402, h-index: 26)
Annals of Nuclear Medicine     Hybrid Journal   (Followers: 4, SJR: 0.68, h-index: 45)
Annals of Operations Research     Hybrid Journal   (Followers: 10, SJR: 1.186, h-index: 78)
Annals of Ophthalmology     Hybrid Journal   (Followers: 12)
Annals of Regional Science     Hybrid Journal   (Followers: 7, SJR: 0.405, h-index: 42)
Annals of Software Engineering     Hybrid Journal   (Followers: 13)
Annals of Solid and Structural Mechanics     Hybrid Journal   (Followers: 9, SJR: 0.553, h-index: 8)
Annals of Surgical Oncology     Hybrid Journal   (Followers: 14, SJR: 1.902, h-index: 127)
Annals of Telecommunications     Hybrid Journal   (Followers: 8, SJR: 0.315, h-index: 25)
Annals of the Institute of Statistical Mathematics     Hybrid Journal   (Followers: 1, SJR: 0.931, h-index: 31)
Antonie van Leeuwenhoek     Hybrid Journal   (Followers: 5, SJR: 0.992, h-index: 87)
Apidologie     Hybrid Journal   (Followers: 4, SJR: 1.14, h-index: 57)
APOPTOSIS     Hybrid Journal   (Followers: 8, SJR: 1.554, h-index: 87)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2, SJR: 0.354, h-index: 27)
Applications of Mathematics     Hybrid Journal   (Followers: 1, SJR: 0.274, h-index: 20)
Applied Biochemistry and Biotechnology     Hybrid Journal   (Followers: 42, SJR: 0.575, h-index: 80)
Applied Biochemistry and Microbiology     Hybrid Journal   (Followers: 16, SJR: 0.267, h-index: 26)
Applied Cancer Research     Open Access  
Applied Categorical Structures     Hybrid Journal   (Followers: 2, SJR: 0.361, h-index: 21)
Applied Composite Materials     Hybrid Journal   (Followers: 49, SJR: 0.705, h-index: 35)
Applied Entomology and Zoology     Partially Free   (Followers: 3, SJR: 0.554, h-index: 34)
Applied Geomatics     Hybrid Journal   (Followers: 3, SJR: 0.323, h-index: 9)
Applied Geophysics     Hybrid Journal   (Followers: 8, SJR: 0.541, h-index: 13)
Applied Intelligence     Hybrid Journal   (Followers: 11, SJR: 0.777, h-index: 43)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4, SJR: 0.358, h-index: 34)
Applied Mathematics & Optimization     Hybrid Journal   (Followers: 6, SJR: 0.955, h-index: 33)
Applied Mathematics - A J. of Chinese Universities     Hybrid Journal   (SJR: 0.275, h-index: 8)
Applied Mathematics and Mechanics     Hybrid Journal   (Followers: 5, SJR: 0.37, h-index: 26)
Applied Microbiology and Biotechnology     Hybrid Journal   (Followers: 63, SJR: 1.262, h-index: 161)
Applied Physics A     Hybrid Journal   (Followers: 9, SJR: 0.535, h-index: 121)
Applied Physics B: Lasers and Optics     Hybrid Journal   (Followers: 24, SJR: 0.983, h-index: 104)
Applied Psychophysiology and Biofeedback     Hybrid Journal   (Followers: 8, SJR: 0.677, h-index: 47)
Applied Research in Quality of Life     Hybrid Journal   (Followers: 11, SJR: 0.288, h-index: 15)
Applied Solar Energy     Hybrid Journal   (Followers: 18, SJR: 0.251, h-index: 6)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4, SJR: 0.351, h-index: 9)
Aquaculture Intl.     Hybrid Journal   (Followers: 22, SJR: 0.613, h-index: 40)
Aquarium Sciences and Conservation     Hybrid Journal   (Followers: 1)
Aquatic Ecology     Hybrid Journal   (Followers: 32, SJR: 0.646, h-index: 44)
Aquatic Geochemistry     Hybrid Journal   (Followers: 4, SJR: 0.764, h-index: 39)
Aquatic Sciences     Hybrid Journal   (Followers: 13, SJR: 1.172, h-index: 53)
Arabian J. for Science and Engineering     Hybrid Journal   (Followers: 5, SJR: 0.345, h-index: 20)
Arabian J. of Geosciences     Hybrid Journal   (Followers: 2, SJR: 0.417, h-index: 16)
Archaeological and Anthropological Sciences     Hybrid Journal   (Followers: 20, SJR: 1.056, h-index: 15)
Archaeologies     Hybrid Journal   (Followers: 12, SJR: 0.397, h-index: 13)
Archiv der Mathematik     Hybrid Journal   (Followers: 1, SJR: 0.597, h-index: 29)
Archival Science     Hybrid Journal   (Followers: 57, SJR: 0.804, h-index: 22)
Archive for History of Exact Sciences     Hybrid Journal   (Followers: 8, SJR: 0.28, h-index: 15)
Archive for Mathematical Logic     Hybrid Journal   (Followers: 2, SJR: 0.946, h-index: 23)
Archive for Rational Mechanics and Analysis     Hybrid Journal   (SJR: 4.091, h-index: 66)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 5, SJR: 0.865, h-index: 40)
Archives and Museum Informatics     Hybrid Journal   (Followers: 132)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 5, SJR: 2.841, h-index: 40)
Archives of Dermatological Research     Hybrid Journal   (Followers: 7, SJR: 0.9, h-index: 65)
Archives of Environmental Contamination and Toxicology     Hybrid Journal   (Followers: 14, SJR: 0.846, h-index: 84)
Archives of Gynecology and Obstetrics     Hybrid Journal   (Followers: 16, SJR: 0.695, h-index: 47)
Archives of Microbiology     Hybrid Journal   (Followers: 8, SJR: 0.702, h-index: 85)
Archives of Orthopaedic and Trauma Surgery     Hybrid Journal   (Followers: 8, SJR: 1.039, h-index: 56)
Archives of Osteoporosis     Hybrid Journal   (Followers: 2, SJR: 1.092, h-index: 13)
Archives of Sexual Behavior     Hybrid Journal   (Followers: 10, SJR: 1.198, h-index: 74)
Archives of Toxicology     Hybrid Journal   (Followers: 17, SJR: 1.595, h-index: 76)
Archives of Virology     Hybrid Journal   (Followers: 5, SJR: 1.086, h-index: 90)
Archives of Women's Mental Health     Hybrid Journal   (Followers: 14, SJR: 1.264, h-index: 50)
Archivio di Ortopedia e Reumatologia     Hybrid Journal  
Archivum Immunologiae et Therapiae Experimentalis     Hybrid Journal   (Followers: 2, SJR: 1.2, h-index: 42)
ArgoSpine News & J.     Hybrid Journal   (SJR: 0.102, h-index: 3)
Argumentation     Hybrid Journal   (Followers: 5, SJR: 0.295, h-index: 18)
Arid Ecosystems     Hybrid Journal   (Followers: 2)
Arkiv för Matematik     Hybrid Journal   (Followers: 1, SJR: 0.948, h-index: 22)
Arnold Mathematical J.     Hybrid Journal   (Followers: 1)
Arthropod-Plant Interactions     Hybrid Journal   (Followers: 2, SJR: 0.797, h-index: 17)
Arthroskopie     Hybrid Journal   (Followers: 1, SJR: 0.145, h-index: 8)
Artificial Intelligence and Law     Hybrid Journal   (Followers: 11, SJR: 0.288, h-index: 25)
Artificial Intelligence Review     Hybrid Journal   (Followers: 14, SJR: 0.948, h-index: 48)
Artificial Life and Robotics     Hybrid Journal   (Followers: 8, SJR: 0.231, h-index: 14)
Asia Europe J.     Hybrid Journal   (Followers: 5, SJR: 0.247, h-index: 9)
Asia Pacific Education Review     Hybrid Journal   (Followers: 11, SJR: 0.371, h-index: 17)
Asia Pacific J. of Management     Hybrid Journal   (Followers: 16, SJR: 1.676, h-index: 50)
Asia-Pacific Education Researcher     Hybrid Journal   (Followers: 12, SJR: 0.353, h-index: 13)
Asia-Pacific Financial Markets     Hybrid Journal   (Followers: 2, SJR: 0.19, h-index: 15)
Asia-Pacific J. of Atmospheric Sciences     Hybrid Journal   (Followers: 19, SJR: 1.006, h-index: 14)
Asian Business & Management     Hybrid Journal   (Followers: 9, SJR: 0.41, h-index: 10)
Asian J. of Business Ethics     Hybrid Journal   (Followers: 9)
Asian J. of Criminology     Hybrid Journal   (Followers: 5, SJR: 0.263, h-index: 8)
AStA Advances in Statistical Analysis     Hybrid Journal   (Followers: 2, SJR: 0.681, h-index: 15)
AStA Wirtschafts- und Sozialstatistisches Archiv     Hybrid Journal   (Followers: 5, SJR: 0.195, h-index: 5)
ästhetische dermatologie & kosmetologie     Full-text available via subscription  

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Journal Cover Astrophysics
  [SJR: 0.243]   [H-I: 11]   [23 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1573-8191 - ISSN (Online) 0571-7256
   Published by Springer-Verlag Homepage  [2352 journals]
  • Hot Dust in Ultraluminous Infrared Galaxies
    • Authors: Yu. A. Shchekinov; E. O. Vasiliev
      Pages: 449 - 461
      Abstract: Ultraluminous infrared galaxies with total luminosities an order of magnitude greater than that of our galaxy over wavelengths of λλ = 10-800 μm are characterized by a high mass concentration of dust. Because of this, the optical thickness of the interstellar gas is extremely high, especially in the central regions of the galaxies, ranging from 1 at millimeter wavelengths to 104 in the visible. The average temperature of the dust in them is about Td=30 K, but the variations from one galaxy to another are large, with Td=20-70 K. The main source of dust in these galaxies seems to be type II supernova bursts and the main heating source is stars. In addition, given that shock waves from supernovae are an effective mechanism for destruction of interstellar dust in our galaxy and the high optical thickness of the gas with respect to the heating radiation from the stars, this conclusion merits detailed analysis. This paper provides estimates of the dust mass balance and details of its heating in these galaxies based on the example of the ultraluminous galaxy closest to us, Arp 220. It is shown that when supernovae are dominant in the production and destruction of dust in the interstellar gas, the resultant dust mass fraction is close to the observed value for Arp 220. It is also found that the observed stellar population of this galaxy can support a high ( Td ≃ 67 K ) temperature if the dust in its central region is concentrated in small, dense (n~105 cm-3) clouds with radii of 0.003 ≲ pc. Mechanisms capable of maintaining an interstellar gas structure in this state are discussed.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9498-1
      Issue No: Vol. 60, No. 4 (2017)
  • Galactic Kinematics Derived From Data in the RAVE5, UCAC4, PPMXL, and Gaia
           TGAS Catalogs
    • Authors: V. V. Vityazev; A. S. Tsvetkov; V. V. Bobylev; A. T. Bajkova
      Pages: 462 - 483
      Abstract: The three-dimensional velocities of stars with high-precision positions, proper motions, and parallaxes from the Gaia TGAS catalog and radial velocities from the RAVE5 catalog are examined. A sample of 92395 stars with estimated ages yields the following kinematic parameters: (U, V, W)=(9.42, 20.34, 7.21)±(0.12, 0.10, 0.09) km/s, Ω = 26.29 ± 0.39 km/s/kpc and Ω′=3.89 ± 0.08 km/s/kpc2, where V0=210±6 km/s (for the assumed R0 = 8.0 ± 0.2 kpc), as well as the Oort constants A=15.57±0.31 km/s/kpc and B = – 10.72±0.50 km/s/kpc. It is shown that the values of the parameters Ω and Ω′ have good stability, depending on the age of the stars. The parameters of the Bottlinger model obtained separately from the radial velocities in the RAVE5 catalog and from the proper motions of the stars in the Gaia TGAS, UCAC4, and PPMXL catalogs are compared. These parameters agree well with one another whether they are determined from the proper motions of the stars in the terrestrial catalogs or from observations reported in the Gaia TGAS catalog and made with the HIPPARCOS and Gaia spacecraft. At the same time, it was found that the parameters of the Bottlinger model calculated using the radial velocities may differ from the corresponding values derived from the proper motions of the stars. A reduction of the radial velocities of the stars in the RAVE5 catalog is proposed that eliminates these differences.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9499-0
      Issue No: Vol. 60, No. 4 (2017)
  • Spatial Distribution of Gamma-Ray Burst Sources
    • Authors: S. I. Shirokov; A. A. Raikov; Yu. V. Baryshev
      Pages: 484 - 496
      Abstract: The spatial distribution of sources of gamma-ray bursts (GRB) with known red shifts is analyzed by the conditional density and pairwise distance methods. The sample of GRB is based on data from the Swift program and contains fluxes, coordinates, and red shifts for 384 GRB sources. Selection effects that distort the true source distribution are taken into account by comparing the observed distribution with fractal and uniform model catalogs. The Malmqvist effect is modeled using an approximation for the visible luminosity function of the GRB. The case of absorption in the galactic plane is also examined. This approach makes it possible to study the spatial structure of the entire sample at one time without artificial truncations. The estimated fractal dimensionality is D = 2.55 ± 0.06 on scales of 2-6 Gpc.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9500-y
      Issue No: Vol. 60, No. 4 (2017)
  • Search for Variability in Young Planetary Nebulae
    • Authors: L. N. Kondratyeva; E. K. Denissyuk; M. A. Krugov
      Pages: 497 - 506
      Abstract: Data from long-term spectral observations of two young planetary nebulae are presented. A significant enhancement of the radiation fluxes in all emission lines and a higher degree of ionization of the gas are detected in the spectrum of M1-46. The opposite effect is observed in the spectrum of M1-65. Over 10 years (2005-2015) the radiative fluxes in the emission lines fell by a factor of 2-3, after which they began to increase. The cause of the observed variability may be a change in the temperature of the central star or a change in the inhomogeneous structure of the nebula through which the ionizing radiation passes.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9501-x
      Issue No: Vol. 60, No. 4 (2017)
  • Improved Orbit and Mass of the Binary Star 61 Cyg Based on Photographic
           Observations at Pulkovo
    • Authors: N. A. Shakht; D. L. Gorshanov; O. O. Vasilkova
      Pages: 507 - 519
      Abstract: Observations of stars close to the sun which, in terms of their physical properties, are possible objects for space missions aimed at searching for planetary components, are made at the Pulkovo Observatory. In this paper we present new orbital elements for the binary star 61 Cyg derived from long-term series of observations at Pulkovo including current data on this star.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9502-9
      Issue No: Vol. 60, No. 4 (2017)
  • Photometric Studies of Stars in the Vicinity of Cyg OB7
    • Authors: N. D. Melikian; J. Gomez
      Pages: 520 - 531
      Abstract: Results of BVRI photometric studies of 131 stars in the stellar association Cyg OB7 are presented. Observational data were obtained with the 2.6-m telescope at the Byurakan Observatory during 2000, 2002, 2004, and 2011 using the ByuFOSC-2 and SCORPIO spectral cameras. Observations made in 2007 on the 182-cm telescope (Asiago, Italy) at the Padova Astronomical Observatory with the AFOSC (Asiago Faint Object Spectrograph and Camera) detector system are also used. Variations with amplitudes ranging from 0m.2 to 2m.16 are detected in 42 of the stars. Variability is observed for the first time in 31 of the 42 stars. The brightness of 32 of the stars was essentially unchanged during the time of our measurements. All of the 42 variables lie very close to the T Tau type stars on a two-color diagram.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9503-8
      Issue No: Vol. 60, No. 4 (2017)
  • Radiation and Thermodynamic Characteristics of Hydrogen Gas Near the State
           of Thermalization
    • Authors: N. A. Katysheva; T. A. Ermolaeva; V. P. Grinin
      Pages: 532 - 543
      Abstract: The thermodynamic characteristics of hydrogen gas during the transition from optically thin at line frequencies to a state of thermalization without external radiation sources are studied. The radiative terms in the stationary equations describing discrete transitions between atomic levels are included in the Sobolev approximation. It is shown that the transition to a state of thermalization with an increase in the optical thickness of the gas at the frequencies of spectral lines can be accompanied by a strong (by almost a factor of 100) increase in the degree of ionization of the gas. Electron-impact ionization from excited levels predominates in this process.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9504-7
      Issue No: Vol. 60, No. 4 (2017)
  • Possibilities for Estimating Horizontal Electrical Currents in Active
           Regions on the Sun
    • Authors: Yu. A. Fursyak; V. I. Abramenko
      Pages: 544 - 552
      Abstract: Part of the “free” magnetic energy associated with electrical current systems in the active region (AR) is released during solar flares. This proposition is widely accepted and it has stimulated interest in detecting electrical currents in active regions. The vertical component of an electric current in the photosphere can be found by observing the transverse magnetic field. At present, however, there are no direct methods for calculating transverse electric currents based on these observations. These calculations require information on the field vector measured simultaneously at several levels in the photosphere, which has not yet been done with solar instrumentation. In this paper we examine an approach to calculating the structure of the square of the density of a transverse electrical current based on a magnetogram of the vertical component of the magnetic field in the AR. Data obtained with the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamic Observatory (SDO) for the AR of NOAA AR 11283 are used. It is shown that (1) the observed variations in the magnetic field of a sunspot and the proposed estimate of the density of an annular horizontal current around the spot are consistent with Faraday’s law and (2) the resulting estimates of the magnitude of the square of the density of the horizontal current \( {j}_{\perp}^2 \) = (0.002− 0.004) A2/m4 are consistent with previously obtained values of the density of a vertical current in the photosphere. Thus, the proposed estimate is physically significant and this method can be used to estimate the density and structure of transverse electrical currents in the photosphere.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9505-6
      Issue No: Vol. 60, No. 4 (2017)
  • Is EG 50 a White or Strange Dwarf'
    • Authors: G. S. Hajyan; Yu. L. Vartanyan
      Pages: 553 - 562
      Abstract: The time dependences of the luminosity of a white dwarf and four strange dwarfs with masses of 0.5 M (the mass of the white dwarf EG 50 with a surface temperature of 2.1·104 K) are determined taking neutrino energy losses into account. It was assumed that these configurations radiate only at the expense of thermal energy reserves. It is shown that the sources of thermal energy owing to nonequilibrium b-processes and the phenomenon of crystallization of electron-nuclear matter are insignificant in determining the cooling time of white and strange dwarfs with masses of 0.5 M⨀. It is shown that in this approximation the time dependences of the luminosity of white and strange dwarfs with masses of 0.5 M⨀ differ significantly only for surface temperatures TR≥7·104 K, so it is impossible to determine whether EG 50 is a white or strange dwarf based on the cooling time.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9506-5
      Issue No: Vol. 60, No. 4 (2017)
  • Maximum Mass of Hybrid Stars in the Quark Bag Model
    • Authors: G. B. Alaverdyan; Yu. L. Vartanyan
      Pages: 563 - 571
      Abstract: The effect of model parameters in the equation of state for quark matter on the magnitude of the maximum mass of hybrid stars is examined. Quark matter is described in terms of the extended MIT bag model including corrections for one-gluon exchange. For nucleon matter in the range of densities corresponding to the phase transition, a relativistic equation of state is used that is calculated with two-particle correlations taken into account based on using the Bonn meson-exchange potential. The Maxwell construction is used to calculate the characteristics of the first order phase transition and it is shown that for a fixed value of the strong interaction constant αs, the baryon concentrations of the coexisting phases grow monotonically as the bag constant B increases. It is shown that for a fixed value of the strong interaction constant αs, the maximum mass of a hybrid star increases as the bag constant B decreases. For a given value of the bag parameter B, the maximum mass rises as the strong interaction constant αs increases. It is shown that the configurations of hybrid stars with maximum masses equal to or exceeding the mass of the currently known most massive pulsar are possible for values of the strong interaction constant αs > 0.6 and sufficiently low values of the bag constant.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9507-4
      Issue No: Vol. 60, No. 4 (2017)
  • Some Consequences of the Expansion of the Universe on Small Scales
    • Authors: H. A. Harutyunian
      Pages: 572 - 581
      Abstract: The possibility of detecting the accelerated expansion of the universe at all its points is examined. Observational data indicative of Hubble expansion on small scales are adduced for this purpose. The validity of current opinion on the equilibrium of systems of cosmic objects is also discussed. It is noted that this opinion is a simple consequence of the unproved Kant-Laplace hypothesis on the formation of cosmic objects and systems of them. It is proposed that a system attached to the cosmological horizon be used as a reference system. It is noted that all points on this sphere are an initial point from which expansion of the observed universe of the given observer began. The numerical value of the acceleration obtained in this way is almost the same as the anomalous acceleration found by space probes.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9508-3
      Issue No: Vol. 60, No. 4 (2017)
  • Effect of the Kerr Metric on Photosperic Radius Expansion in X Ray Burst
    • Authors: S. Kalita; A. Barman
      Pages: 582 - 591
      Abstract: The main objective of this paper is to study general relativistic effects on the photospheric radius expansion during an X-ray burst. We examine how the Kerr metric causes a shift in the effective temperature and radiation flux with respect to the Schwarzschild values during mass accretion onto a neutron star or a black hole resulting in the X-ray burst. The spin of the compact object is used up to the maximal Kerr limit χ = 0.99 with different latitudes of accretion emission. The amplitude of temperature shift relative to the Schwarzschild case is found to be δT/T ≈  − (10−3 − 10−4) for the range χ = 0.1 − 0.99 at latitudes θ = 0o , 30o, 45o and 88o. The ratio of emission flux in the Kerr metric to that in the Schwarzschild metric, F(K)/F(S), is found to be less than unity. It goes up to a maximum of 0.9 for the lowest nonzero value of the spin parameter (i.e., 0.1). For the maximal Kerr limit, χ = 0.99 , it saturates near 0.8. This effect is more prominent towards the pole. This reduction in temperature and flux is found to be consistent with the absence of photospheric radius expansion in the X Ray burst LMXB 4U 1608-52, observed by NuSTAR. Although this is not uniquely ascribed to the metric, it is believed that the spacetime metric effect in the burst phenomena can be used as a probe for testing general relativity. Also, the shift in temperature or the radiation flux might have an observable signature in the element synthesis processes in such environments.
      PubDate: 2017-12-01
      DOI: 10.1007/s10511-017-9509-2
      Issue No: Vol. 60, No. 4 (2017)
  • The Star Formation Regions SNO 76 and RCW 105
    • Authors: A. L. Gyulbudaghian
      Pages: 348 - 357
      Abstract: Two star formation regions in the southern sky are discussed. The first of these, SNO 76, consists of stars that form a trapezium system, along with IR stars and stars with dust envelopes. One of these stars is associated with a cometary nebula. This star is a variable with an amplitude of 3m.77. This system is associated with the point IR source IRAS 10138-6004. 12CO(1-0) observations of the molecular cloud associated with this star formation region reveal the presence of red and blue outflows. The second star formation region, RCW 105, consists of two groups of stars together with stars on bright filaments. These stars include IR stars and stars with dust envelopes. This star formation region is embedded in a radial system of type-I dark globules that is formed by the star HD 144969. This system is not included in any of the known catalogs of radial systems.
      PubDate: 2017-09-01
      DOI: 10.1007/s10511-017-9488-3
      Issue No: Vol. 60, No. 3 (2017)
  • Numerical Simulation of Astrophysical Jets: Interaction with Surrounding
    • Authors: O. Donmez; A. Aktas; U. Ilter
      Abstract: Propagation of astrophysical jets inside an ambient medium transports a large amount of energy to surrounding materials as a consequence of interactions. These interactions have a crucial effect on the evolution and dynamics of the jets. They can cause the formation of the jet’s head, which dissipates its energy. In this paper, we have numerically modeled the evolution of jet’s dynamics to understand the effects of the critical parameters (Mach numbers, jet velocity, densities, pressures of the accelerated the jet and medium, sound speeds, and Lorentz factor) on the head of the jet, jet-cocoon, vortexes and shocks. When the jet propagates inside the overdense region, we observe clear evidence for deceleration of the jet and find a more complex structure. In the underdense cases, almost no back-flows and cocoons are developed. We have also modeled the pulsed type jets propagating into the overdense region and found a very rich internal structure of the jet, such as cocoon, knots, vortexes, etc. They could explain the structure of jets seen in Herbig-Haro bows and XZ Tauri proto-jet.
      PubDate: 2017-09-26
      DOI: 10.1007/s10511-017-9497-2
  • Effect of the Nonuniformity of Radio Sources on Estimates of Their
           Physical Parameters
    • Authors: V. S. Artyukh; V. S. Nedora
      Abstract: Estimating the physical parameters of nonuniform radio sources in active galactic nuclei (AGN) requires knowledge of the angular dimensions of radio sources at the low frequencies where a steep slope (cutoff) in the low-frequency spectrum (opacity region) is observed. In most compact radio sources, the low-frequency cutoff lies in the meter wavelength range. At present there are no VLBI systems operating at meter wavelengths, so the low-frequency dimensions of compact radio sources in AGN cannot be measured directly. Here we propose a method for estimating the low-frequency angular dimensions of compact radio sources (in the opacity region) based on the shape of their spectra.
      PubDate: 2017-09-26
      DOI: 10.1007/s10511-017-9485-6
  • Flare Activity of the Sun and Variations in its UV Emission During Cycle
    • Authors: E. A. Bruevich; G. V. Yakunina
      Abstract: The flare activity and ultraviolet emission of the sun during its 24th cycle are analyzed. As opposed to cycles 21-23, where the most powerful flares were observed during the decay phase, in cycle 24 the most powerful flares (>X2.7) occurred in the rising phase and at the maximum. Regression fits of the UV indices to the overall radiation level from the sun are substantially different for cycle 24 compared to cycles 21-23. It is found that for the flare of August 9, 2011 (SDO and GOES-15 observations), the flare propagates in a direction from the upper corona to the lower corona in the chromosphere. A study of the N-S asymmetry in the distribution of the flares in cycle 24 reveals a strong predominance of flares in the N-hemisphere in 2011 and in the S-hemisphere in 2014. It is also found that during cycles 23 and 24, the delays in the onset of proton events relative to the onset of the flares that cause them have a distribution with a distinct maximum corresponding to a delay of 2 hours for protons with energies >10 MeV, as well as for those with energies >100 MeV.
      PubDate: 2017-09-26
      DOI: 10.1007/s10511-017-9492-7
  • An Unnoticed Significance of the Chandrasekhar Mass Limit
    • Authors: S. Kalita
      Abstract: Simultaneous occurrence of the three fundamental constants G, ħ , and c and hence the role of Planck mass in the Chandrasekhar mass limit is critically examined in the light of cosmology, by incorporating the cosmological constant through vacuum fluctuation at Planck scale and the holographic principle. A new interpretation of the cosmological constant problem is also put forward.
      PubDate: 2017-09-26
      DOI: 10.1007/s10511-017-9495-4
  • Photometric Period of the Star PZ Mon
    • Authors: K. A. Antonyuk; N. I. Bondar’; N. V. Pit’
      Abstract: Results are presented from a search for periodic variations in the brightness and color indices of the active star PZ Mon based on many years of photometric data from 1992 to 2015. The photometric period derived from the entire set of observations is 34.16 days, but the period may vary by 1.5% within individual intervals. The color index V-R varies with the same period. These variations are indicative of reddening of the star with decreasing brightness. A correlation between the values exists over the entire observation interval. The variations in B-V occur over an interval of 26-28 days. A nonuniqueness in these variations shows up in a brightness-color index diagram: a reduction in the color index with decreasing brightness is observed in some epochs, which can be explained in terms of a spottedness model by the presence of cold, as well as hot, formations on the star’s surface.
      PubDate: 2017-09-26
      DOI: 10.1007/s10511-017-9490-9
  • Mg/Si Mineralogical Ratio of Low-Mass Planet Hosts. Correction for the
           NLTE Effects
    • Authors: V. Adibekyan; H. M. Gonçalves da Silva; S. G. Sousa; N. C. Santos; E. Delgado Mena; A. A. Hakobyan
      Abstract: Mg/Si and Fe/Si ratios are important parameters that control the composition of rocky planets. In this work we applied non-LTE correction to the Mg and Si abundances of stars with and without planets to confirm/reject our previous findings that [Mg/Si] atmospheric abundance is systematically higher for Super-Earth/Neptune-mass planet hosts than stars without planets. Our results show that the small differences of stellar parameters observed in these two groups of stars are not responsible for the already reported difference in the [Mg/Si] ratio. Thus, the high [Mg/Si] ratio of Neptunian hosts is probably related to the formation efficiency of these planets in such environments.
      PubDate: 2017-09-26
      DOI: 10.1007/s10511-017-9486-5
  • Physical Processes in the “Feet” of Solar Prominences
    • Authors: M. Sikharulidze; R. Chigladze; D. Khutsishvili; T. Kvernadze; E. Khutshishvili; V. Kakhiani; G. Kurkhuli
      Abstract: Spectrograms of hydrogen Hα and helium D3 were obtained with a large non-eclipsing coronagraph on November 21, 2012 and July 20, 2015 for a study of the velocities of the plasma in prominences at the Abastumani Astrophysical Observatory. An analysis of this data yielded the following major results: an asymmetry is observed in the time variations in the Doppler velocities and half widths of the Hα prominences. This asymmetry appears in roughly 40% of the 227 spectrograms that were studied. This kind of asymmetry is observed in 70% of the 320 D3 spectrograms that were studied. In the “feet” of the Hα prominences, the Doppler velocities vary over a range of approximately -9 to -15 km/s, and in the “feet” of the D3 prominences, from -8 to -18 km/s. For the Hα prominences the period of the oscillations in the velocity varies over 3-5 min and the period of the oscillations in the half width ranges from 5 to 12 min. For the D3 prominences the period of the oscillations in the Doppler velocities varies over 7-10 min, and the period of the oscillations in the half width ranges from 5-10 min.
      PubDate: 2017-09-26
      DOI: 10.1007/s10511-017-9493-6
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