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Publisher: Springer-Verlag   (Total: 2335 journals)

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Showing 1 - 200 of 2335 Journals sorted alphabetically
3D Research     Hybrid Journal   (Followers: 19, SJR: 0.214, h-index: 10)
4OR: A Quarterly J. of Operations Research     Hybrid Journal   (Followers: 9, SJR: 1.073, h-index: 25)
AAPS J.     Hybrid Journal   (Followers: 16, SJR: 1.192, h-index: 74)
AAPS PharmSciTech     Hybrid Journal   (Followers: 6, SJR: 0.718, h-index: 54)
Abdominal Imaging     Hybrid Journal   (Followers: 16, SJR: 0.723, h-index: 60)
Abhandlungen aus dem Mathematischen Seminar der Universitat Hamburg     Hybrid Journal   (Followers: 2, SJR: 0.447, h-index: 12)
Academic Psychiatry     Full-text available via subscription   (Followers: 22, SJR: 0.492, h-index: 32)
Academic Questions     Hybrid Journal   (Followers: 7, SJR: 0.135, h-index: 6)
Accreditation and Quality Assurance: J. for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 25, SJR: 0.378, h-index: 30)
Acoustical Physics     Hybrid Journal   (Followers: 10, SJR: 0.355, h-index: 20)
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: 5, SJR: 0.419, h-index: 25)
Acta Diabetologica     Hybrid Journal   (Followers: 14, 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: 3)
Acta Geodaetica et Geophysica     Hybrid Journal   (Followers: 1, SJR: 0.294, h-index: 13)
Acta Geotechnica     Hybrid Journal   (Followers: 6, SJR: 1.818, h-index: 22)
Acta Informatica     Hybrid Journal   (Followers: 5, SJR: 0.524, h-index: 32)
Acta Mathematica     Hybrid Journal   (Followers: 9, 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: 5, 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: 18, SJR: 0.898, h-index: 52)
Acta Mechanica Sinica     Hybrid Journal   (Followers: 4, SJR: 0.426, h-index: 29)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5, SJR: 0.525, h-index: 18)
Acta Meteorologica Sinica     Hybrid Journal   (Followers: 3, SJR: 0.524, h-index: 14)
Acta Neurochirurgica     Hybrid Journal   (Followers: 7, SJR: 0.833, h-index: 73)
Acta Neurologica Belgica     Hybrid Journal   (SJR: 0.348, h-index: 27)
Acta Neuropathologica     Hybrid Journal   (Followers: 3, SJR: 6.61, h-index: 117)
Acta Oceanologica Sinica     Hybrid Journal   (Followers: 3, SJR: 0.295, h-index: 17)
Acta Parasitologica     Hybrid Journal   (Followers: 9, 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)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5, SJR: 0.103, h-index: 4)
ADHD Attention Deficit and Hyperactivity Disorders     Hybrid Journal   (Followers: 20, SJR: 0.871, h-index: 15)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 7)
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: 34, SJR: 0.959, h-index: 44)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15, SJR: 1.255, h-index: 44)
Advances in Contraception     Hybrid Journal   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 48, SJR: 1.113, h-index: 14)
Advances in Gerontology     Partially Free   (Followers: 7, SJR: 0.141, h-index: 3)
Advances in Health Sciences Education     Hybrid Journal   (Followers: 23, 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: 40, SJR: 0.637, h-index: 89)
Advances in Therapy     Hybrid Journal   (Followers: 6, SJR: 0.79, h-index: 44)
Aegean Review of the Law of the Sea and Maritime Law     Hybrid Journal   (Followers: 7)
Aequationes Mathematicae     Hybrid Journal   (Followers: 2, SJR: 0.882, h-index: 23)
Aerobiologia     Hybrid Journal   (Followers: 1, SJR: 0.511, h-index: 36)
Aesthetic Plastic Surgery     Hybrid Journal   (Followers: 8, SJR: 0.821, h-index: 49)
African Archaeological Review     Hybrid Journal   (Followers: 14, 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: 6, 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: 3)
Agriculture and Human Values     Hybrid Journal   (Followers: 12, SJR: 1.197, h-index: 49)
Agroforestry Systems     Hybrid Journal   (Followers: 20, SJR: 0.64, h-index: 56)
Agronomy for Sustainable Development     Hybrid Journal   (Followers: 10, SJR: 1.732, h-index: 59)
AI & Society     Hybrid Journal   (Followers: 7, 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: 2, SJR: 0.706, h-index: 19)
Akupunktur & Aurikulomedizin     Full-text available via subscription   (Followers: 1)
Algebra and Logic     Hybrid Journal   (Followers: 2, SJR: 0.566, h-index: 18)
Algebra Universalis     Hybrid Journal   (Followers: 2, SJR: 0.388, h-index: 22)
Algebras and Representation Theory     Hybrid Journal   (SJR: 0.868, h-index: 20)
Algorithmica     Hybrid Journal   (Followers: 7, 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: 3, 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: 14, SJR: 1.094, h-index: 87)
American J. of Cardiovascular Drugs     Hybrid Journal   (Followers: 10, SJR: 0.864, h-index: 39)
American J. of Community Psychology     Hybrid Journal   (Followers: 24, SJR: 1.237, h-index: 83)
American J. of Criminal Justice     Hybrid Journal   (Followers: 5, SJR: 0.634, h-index: 13)
American J. of Cultural Sociology     Hybrid Journal   (Followers: 11, 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: 10, 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: 5, 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  
Analysis of Verbal Behavior     Hybrid Journal   (Followers: 4)
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: 13, 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: 10, 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: 8)
Annals of Dyslexia     Hybrid Journal   (Followers: 9, SJR: 0.857, h-index: 40)
Annals of Finance     Hybrid Journal   (Followers: 26, SJR: 0.686, h-index: 14)
Annals of Forest Science     Hybrid Journal   (Followers: 4, 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: 13, SJR: 1.117, h-index: 62)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 6, SJR: 0.593, h-index: 42)
Annals of Microbiology     Hybrid Journal   (Followers: 9, SJR: 0.402, h-index: 26)
Annals of Nuclear Medicine     Hybrid Journal   (Followers: 5, SJR: 0.68, h-index: 45)
Annals of Operations Research     Hybrid Journal   (Followers: 8, SJR: 1.186, h-index: 78)
Annals of Regional Science     Hybrid Journal   (Followers: 7, SJR: 0.405, h-index: 42)
Annals of Software Engineering     Hybrid Journal   (Followers: 12)
Annals of Solid and Structural Mechanics     Hybrid Journal   (Followers: 9, SJR: 0.553, h-index: 8)
Annals of Surgical Oncology     Hybrid Journal   (Followers: 11, SJR: 1.902, h-index: 127)
Annals of Telecommunications     Hybrid Journal   (Followers: 7, 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: 7, 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: 45, SJR: 0.575, h-index: 80)
Applied Biochemistry and Microbiology     Hybrid Journal   (Followers: 17, SJR: 0.267, h-index: 26)
Applied Categorical Structures     Hybrid Journal   (Followers: 2, SJR: 0.361, h-index: 21)
Applied Composite Materials     Hybrid Journal   (Followers: 45, SJR: 0.705, h-index: 35)
Applied Entomology and Zoology     Partially Free   (Followers: 2, SJR: 0.554, h-index: 34)
Applied Geomatics     Hybrid Journal   (Followers: 3, SJR: 0.323, h-index: 9)
Applied Geophysics     Hybrid Journal   (Followers: 7, SJR: 0.541, h-index: 13)
Applied Intelligence     Hybrid Journal   (Followers: 13, SJR: 0.777, h-index: 43)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 3, SJR: 0.358, h-index: 34)
Applied Mathematics & Optimization     Hybrid Journal   (Followers: 4, 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: 4, SJR: 0.37, h-index: 26)
Applied Microbiology and Biotechnology     Hybrid Journal   (Followers: 61, SJR: 1.262, h-index: 161)
Applied Physics A     Hybrid Journal   (Followers: 8, SJR: 0.535, h-index: 121)
Applied Physics B: Lasers and Optics     Hybrid Journal   (Followers: 22, SJR: 0.983, h-index: 104)
Applied Psychophysiology and Biofeedback     Hybrid Journal   (Followers: 5, SJR: 0.677, h-index: 47)
Applied Research in Quality of Life     Hybrid Journal   (Followers: 10, SJR: 0.288, h-index: 15)
Applied Solar Energy     Hybrid Journal   (Followers: 16, 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: 21, SJR: 0.613, h-index: 40)
Aquarium Sciences and Conservation     Hybrid Journal   (Followers: 1)
Aquatic Ecology     Hybrid Journal   (Followers: 31, SJR: 0.646, h-index: 44)
Aquatic Geochemistry     Hybrid Journal   (Followers: 3, SJR: 0.764, h-index: 39)
Aquatic Sciences     Hybrid Journal   (Followers: 12, 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: 1, SJR: 0.417, h-index: 16)
Archaeological and Anthropological Sciences     Hybrid Journal   (Followers: 21, SJR: 1.056, h-index: 15)
Archaeologies     Hybrid Journal   (Followers: 12, SJR: 0.397, h-index: 13)
Archiv der Mathematik     Hybrid Journal   (SJR: 0.597, h-index: 29)
Archival Science     Hybrid Journal   (Followers: 51, SJR: 0.804, h-index: 22)
Archive for History of Exact Sciences     Hybrid Journal   (Followers: 7, SJR: 0.28, h-index: 15)
Archive for Mathematical Logic     Hybrid Journal   (Followers: 1, 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: 4, SJR: 0.865, h-index: 40)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4, SJR: 2.841, h-index: 40)
Archives of Dermatological Research     Hybrid Journal   (Followers: 6, SJR: 0.9, h-index: 65)
Archives of Environmental Contamination and Toxicology     Hybrid Journal   (Followers: 10, 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: 9, SJR: 1.198, h-index: 74)
Archives of Toxicology     Hybrid Journal   (Followers: 16, SJR: 1.595, h-index: 76)
Archives of Virology     Hybrid Journal   (Followers: 4, SJR: 1.086, h-index: 90)
Archives of Women's Mental Health     Hybrid Journal   (Followers: 13, 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: 4, SJR: 0.295, h-index: 18)
Arid Ecosystems     Hybrid Journal   (Followers: 3)
Arkiv för Matematik     Hybrid Journal   (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: 8, SJR: 0.288, h-index: 25)
Artificial Intelligence Review     Hybrid Journal   (Followers: 15, 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: 4, SJR: 0.247, h-index: 9)
Asia Pacific Education Review     Hybrid Journal   (Followers: 9, SJR: 0.371, h-index: 17)
Asia Pacific J. of Management     Hybrid Journal   (Followers: 11, SJR: 1.676, h-index: 50)
Asia-Pacific Education Researcher     Hybrid Journal   (Followers: 11, 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: 20, SJR: 1.006, h-index: 14)
Asian Business & Management     Hybrid Journal   (Followers: 7, SJR: 0.41, h-index: 10)
Asian J. of Business Ethics     Hybrid Journal   (Followers: 7)
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  
Astronomy and Astrophysics Review     Hybrid Journal   (Followers: 21, SJR: 4.511, h-index: 44)
Astronomy Letters     Hybrid Journal   (Followers: 19, SJR: 0.58, h-index: 30)
Astronomy Reports     Hybrid Journal   (Followers: 12, SJR: 0.473, h-index: 23)
Astrophysical Bulletin     Hybrid Journal   (Followers: 2, SJR: 0.469, h-index: 11)
Astrophysics     Hybrid Journal   (Followers: 22, SJR: 0.243, h-index: 11)

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Journal Cover Astronomy Reports
  [SJR: 0.473]   [H-I: 23]   [12 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1562-6881 - ISSN (Online) 1063-7729
   Published by Springer-Verlag Homepage  [2335 journals]
  • Coronagraphic methods for detecting faint astronomical objects near bright
           ones: Application to the 2.5-m telescope of Sternberg Astronomical
           Institute
    • Authors: A. M. Cherepashchuk; O. I. Bugaenko; I. S. Kim; V. V. Popov
      Pages: 169 - 177
      Abstract: Possible methods for reducing the instrumental background of astronomical telescopes are discussed: the classical Lyot coronagraphic method, the multi-cascade coronagraphic method, the use of special masks in the plane of the entrance aperture, and the use of super-smooth and medium-smooth primary optics. For the first time, analytical expressions describing the intensity distribution at the exit pupil are presented for the case when a mask is placed in the primary focal plane in order to block the light from a bright object. An algorithm for computing the point-spread function (PSF) of a coronagraphic telescope employing super-smooth primary optics and the coronagraphic method is proposed. Computed PSFs for the 2.5-m telescope of the Caucasian Mountain Observatory of Sternberg Astronomical Institute are presented, without allowance for diffusive and turbulent scattering in the Earth’s atmosphere, and for operation both without coronagraphic elements and in the coronagraphic mode of the telescope.
      PubDate: 2017-03-01
      DOI: 10.1134/s1063772917030039
      Issue No: Vol. 61, No. 3 (2017)
       
  • Giant pulses of the Crab Nebula pulsar as an indicator of a strong
           electromagnetic wave
    • Authors: M. V. Popov; A. G. Rudnitskii; V. A. Soglasnov
      Pages: 178 - 186
      Abstract: The spectra and visibility functions of giant pulses of the Crab Nebula pulsar derived from VLBI observations carried out through the “RadioAstron” project in 2015 are analyzed. Parameters of the scattering of the pulses in the interstellar medium are measured, namely, the scattering time and decorrelation bandwidth. A comparative analysis of the shapes of the spectra and visibility functions of giant pulses obtained in real observations and via modeling of their scattering is carried out. The results suggest the presence of short bursts (dt < 30 ns) in the structure of the giant pulses at 1668 MHz, whose brightness temperatures exceed 1038 K. These pulses propagate in the pulsar magnetosphere in a strong electromagneticwave regime, leading to the generation of additional radiation perpendicular to the direction of propagation of the giant pulses. This radiation may be associated with anomalous components of the mean pulse profile observed at frequencies above 4 GHz.
      PubDate: 2017-03-01
      DOI: 10.1134/s1063772917030064
      Issue No: Vol. 61, No. 3 (2017)
       
  • The dynamics and structure of plasma inhomogeneities in the Crab Nebula
    • Authors: B. Ya. Losovskii
      Pages: 187 - 192
      Abstract: The results of studies of the dynamics and structure of plasma inhomogeneities in the Crab Nebula carried out during 2002–2015 at 111 MHz on the Large Phased Array of the Pushchino Radio Astronomy Observatory are presented. Giant pulses of the pulsar PSR B0531+21 were observed and analyzed using specialized software designed to enable characterization of the scattering of a pulse via modeling of its passage through the scattering medium. The results of this analysis for the scattering of giant pulses are compared to variations in the dispersion measure, derived using data from Jodrell Bank Observatory (United Kingdom). Numerous non-stationary events associated with enhanced scattering are identified during the indicated period. The strongest scattering was observed during 2012–2014. The corresponding data are interpreted as eclipses of the pulsar by filaments in the Crab Nebula. A correlation between the variations in the scattering and dispersion measure is observed.
      PubDate: 2017-03-01
      DOI: 10.1134/s1063772917030052
      Issue No: Vol. 61, No. 3 (2017)
       
  • Determining basic characteristics of stars from evolutionary computations
    • Authors: S. G. Sichevskij
      Pages: 193 - 205
      Abstract: A technique for determining a star’s radius from its atmospheric characteristics (effective temperature, surface gravity, and metallicity) is realized based on modernmodel computations of the stellar internal structure and evolution. The atmospheric characteristics can also be used to find the mass and luminosity of the star. The star’s rate of evolution and the initial mass function are taken into account when determining the stellar characteristics, increasing the correctness of the results. Computations of stellar evolution of with and without the stellar rotation taken into account make it possible to remove ambiguity due to missing data on the star’s rotational velocity. The results are checked and uncertainties estimated using stars occupying two heavily populated regions in the Hertzsprung–Russell diagram that have been well studied using various methods: the main sequence and red giant branch. Good agreement with the observations is achieved; there are almost no systematic deviations of the derived point estimates of the fundamental characteristics. The metallicities of the individual components of eclipsing variable stars are estimated using observational data on for such stars displaying lines of both components in their spectra. These metallicities were determined as a function of the stellar masses in a way that eliminates systematic deviations in the derived fundamental characteristics.
      PubDate: 2017-03-01
      DOI: 10.1134/s1063772917030076
      Issue No: Vol. 61, No. 3 (2017)
       
  • A dynamical study of the multiple system 17 Cygni ABFG
    • Authors: L. G. Romanenko
      Pages: 206 - 220
      Abstract: Adynamical study of the relative motions of the components of the inner pairs AB (ADS 12913) and FG (ADS 12889) of the quadruple heirarchical system 17 Cygni (WDS 19464+3344) is presented, as well as analysis of themotions of the outer pair AB–FG. The study is based on CCD observations obtained on the 26-inch refractor of the Pulkovo Observatory (2003–2013), position observations from the WDS catalog, Hipparcos parallaxes, and radial velocities of the components from literature data. A family of orbits for 17 Cyg AB is obtained for the first time, and has a most probable period of 6200 yrs. The apparent motion parameters (AMP) method is used, since the entire visible arc of the orbit over 1832–2013 is only ~4◦. The AMP method is also used to calculate the orbit of the 17 Cyg FG pair, which has a period of 238 yrs, yielding results in good agreement with the orbits derived in other studies. The ephemerides of the obtained AMP orbits, the position data for the AF pair from the WDS catalog (11 positions during 1893–2002), and Pulkovo CCD observations for 2007–2013 are used to calculate the apparent motion parameters of AB–FG outer pair, as well as a family of close-to-parabolic orbits with periods of 3.7 million years ormore. All the orbits (for both the inner and the outer pairs) are steeply inclined to theGalactic plane. Monte Carlo simulations are used to compute the probability that the outer pair is gravitationally bound, which is 47%. The similarity of the proper motions and radial velocities of all the components provides evidence that they all belong to a single stellar stream. Data from the CNS3 catalog are used to compose a list of candidate members of this stream.
      PubDate: 2017-03-01
      DOI: 10.1134/s1063772917020056
      Issue No: Vol. 61, No. 3 (2017)
       
  • Long-term variations in the spottedness of BY Dra M dwarfs
    • Authors: I. Yu. Alekseev; A. V. Kozhevnikova
      Pages: 221 - 232
      Abstract: The results of a spottedness study for twelve red dwarf stars covering several decades and based on a vast amount of photometric observations are presented. The analysis makes use of multicolor (UBV RI) photometric monitoring of ten of these stars since 1991 at the Crimean Astrophysical Observatory, as well as data from the literature. The spottedness parameters for selected active BY Dra red dwarfs have been refined using an improved zonal model for the spotted stellar atmospheres to allow for the possible presence of two active longitudes on the stars. Time variations in the spot activity of these systems are analyzed in order to look for possible cycles. Three of the stars show a drift of their spots in the latitude towards the stellar poles; however, the magnitude of this latitude drift is a factor of two to three lower than the analogous value for sunspots. All the stars except for YZ CMi display relationships between the area of the spots and their latitude, with correlation coefficients R from 0.67 to 0.97. Evidence for the presence of activity cycles with durations from 25 to 40 years is found for six stars, which are characterized by synchronous variations in the areas and latitudes of their spots, as well as of the overall photometric brightness.
      PubDate: 2017-03-01
      DOI: 10.1134/s1063772917030015
      Issue No: Vol. 61, No. 3 (2017)
       
  • Corotating structures in the solar wind from 111-MHz observations of
           interplanetary scintillations at large elongations
    • Authors: A. V. Glyantsev; S. A. Tyul’bashev; I. V. Chashei; V. I. Shishov; L. B. Potapova
      Pages: 233 - 238
      Abstract: Results of continuous 111 MHz observations of interplanetary scintillations of the strong radio source 3C 48 at elongations larger than 80◦ out on the Large Phased Array (LPA) of the Lebedev Physical Institute are reported. The data were taken during a four-year interval, from 2012 to 2015, near the maximum of the 24th solar-activity cycle. The averaged elongation dependence of the scintillation index and similar dependences for individual years during the approach and recession phases suggest the presence of a periodic modulation with a 26-day period, which is masked by day-to-day variations. This periodic modulation can be explained by the existence of a long-lived region of enhanced plasma density adjacent to the solar equator during the solar-activity maximum. It is shown that the scintillation timescale increases in the transition to elongations exceeding 90◦.
      PubDate: 2017-03-01
      DOI: 10.1134/s1063772917030040
      Issue No: Vol. 61, No. 3 (2017)
       
  • Discontinuous plasma flows near reconnecting current layers in solar
           flares
    • Authors: S. I. Bezrodnykh; N. P. Kolesnikov; B. V. Somov
      Pages: 239 - 255
      Abstract: A model for magnetic reconnection in high-conductivity plasma in the solar corona is analyzed in a strong-magnetic-field approximation. The model includes a Syrovatskii current layer and magnetohydrodynamic (MHD) discontinuities attached to the ends of the layer. A two-dimensional analytical solution for the magnetic field is used to compute the distributions of the plasma flow velocity and plasma density in the vicinity of the corresponding current configuration. The properties of jumps in the density and velocity along the attached discontinuities are studied. Based on the character of the variations of the magnetic field and plasma flows at the MHD discontinuities, it is shown that, with the parameter values considered, an MHDdiscontinuity can include regions of trans-Alfvénic, fast, and slowshocks. The results obtained could be useful to explain the presence of “super-hot” (with effective electron temperatures exceeding 10 keV) plasma in solar flares. Other possible applications of the theory of discontinuous flows near regions of magnetic reconnection to analogous non-stationary phenomena in astrophysical plasmas are noted.
      PubDate: 2017-03-01
      DOI: 10.1134/s1063772917030027
      Issue No: Vol. 61, No. 3 (2017)
       
  • Dust in galaxy clusters
    • Authors: O. L. Polikarpova; Yu. A. Shchekinov
      Pages: 89 - 102
      Abstract: The conditions for the destruction of dust in hot gas in galaxy clusters are investigated. It is argued that extinction measurements can be subject to selection effects, hindering their use in obtaining trustworthy estimates of dust masses in clusters. It is shown, in particular, that the ratio of the dust mass to the extinction M d /S d increases as dust grains are disrupted, due to the rapid destruction of small grains. Over long times, this ratio can asymptotically reach values a factor of three higher than the mean value in the interstellar medium in the Galaxy. This lowers dust-mass estimates based on measurements of extinction in galaxy clusters. The characteristic lifetime of dust in hot cluster gas is determined by its possible thermal isolation by the denser medium of gas fragments within which the dust is ejected from galaxies, and can reach 100–300 million years, depending on the kinematics and morphology of the fragments. As a result, the mass fraction of dust in hot cluster gas can reach 1–3% of the Galactic value. Over its lifetime, dust can also be manifest through its far-infrared emission. The emission characteristics of the dust change as it is disrupted, and the ratio of the fluxes at 350 and 850 μm can increase appreciably. This can potentially serve as an indicator of the state of the dust and ambient gas.
      PubDate: 2017-02-01
      DOI: 10.1134/s1063772917020044
      Issue No: Vol. 61, No. 2 (2017)
       
  • Diagnostics for the elemental composition of protostellar objects
    • Authors: O. V. Kochina; D. S. Wiebe
      Pages: 103 - 114
      Abstract: The sensitivity of a number of aspects of the chemical evolution of a molecular cloud to its elemental composition is investigated. Four models are considered: one with high metallicity, for which the evolution proceeds exclusively in the gas phase, two with low metallicity, for which processes proceed both in the gas phase and on grain surfaces, and a model with low metallicity and an artificially reduced oxygen content. One of the low-metallicity models initially contains only neutral components, while some initial ionization of atoms of heavy elements is included in the other models. A network of chemical reactions, including a detailed description of the chemistry of deuterium compounds, is used to analyze this sensitivity. It is shown that the initial composition affects the chemical evolution of most components in some way, but this influence is sometimes negligible. The inclusion of certain chemical factors can be important, such as surface reactions and the loss of a substantial fraction of atoms of heavy elements that are in grains. However, some components are influenced by even small variations in the initial and elemental compositions. One such component is the DCO+ ion, whose evolution is sensitive to the initial degree of ionization of atoms of heavy elements, even if the set of reactions included and the elemental composition are the same in different cases. The possible use of HD and HF as indicators of the presence of molecular hydrogen is also considered. HF reliably traces H2 at times exceeding 105 years under the physical conditions considered. However,HD is not a reliable indicator of H2 at the densities characteristic for protostellar clouds.
      PubDate: 2017-02-01
      DOI: 10.1134/s1063772917020019
      Issue No: Vol. 61, No. 2 (2017)
       
  • Parameters of radio pulsars in binary systems and globular clusters
    • Authors: A. A. Loginov; I. F. Malov
      Pages: 115 - 121
      Abstract: The parameters of radio pulsars in binary systems and globular clusters are investigated. It is shown that such pulsars tend to have short periods (of the order of several milliseconds). Themagnetic fields of most of the pulsars considered are weak (surface fields of the order of 108−109 G). This corresponds to the generally accepted view that short-period neutron stars are spun up by angular momentum associated with the stellar wind from a companion. However, the fields at the light cylinders in these objects are two to three orders of magnitude higher than for the main population of single neutron stars. The dependence of the pulse width on the period does not differ from the corresponding dependences for single pulsars, assuming the emission is generated inside the polar cap, at moderate distances from the surface or near the light cylinder. The radio luminosities of pulsars in binary systems do not show the correlation with the rate of loss of rotational energy that is characteristic for single pulsars, probably due to the influence of accreting matter from a companion. Moreover, accretion apparently decreases the power of the emergent radiation, and can explain the observed systematic excess of the radio luminosity of single pulsars compared to pulsars in binary systems. The distributions and dependences presented in the article support generally accepted concepts concerning the processes occurring in binary systems containing neutron stars.
      PubDate: 2017-02-01
      DOI: 10.1134/s106377291701005x
      Issue No: Vol. 61, No. 2 (2017)
       
  • Spots and the activity of M dwarfs from observations with the Kepler Space
           Telescope
    • Authors: E. S. Dmitrienko; I. S. Savanov
      Pages: 122 - 129
      Abstract: A method for estimating the spottedness parameter S (the spotted area as a fraction of the surface of an active star) proposed earlier is applied to an analysis of activity in 1570 M dwarf stars. The analysis is based on observational material obtained with the Kepler Space Telescope, as well as data on the fluxes of the studied objects in the near and far ultraviolet (NUV and FUV) based on data from the GALEX space telescope. The variations of S with the ages of the stars are studied (four groups with different ages are distinguished), as well as variations of S with their rotational periods. A diagram characterizing the relationship between S and the Rossby number Ro resembles the classical dependence of the X-ray luminosities of active stars on Ro, and a saturation regime is attained at the same value, Ro = 0.13. Moreover, objects with ages of more than 100 million years do not form a single sequence (and stars older than 900 million years possess surface spottednesses of order 1%). The S−Ro dependence obtained could expand possibilities for analyzing the dependence of the X-ray luminosities of active stars on their Rossby numbers, and could also be applied to refine parameters characterizing the action of dynamo mechanisms, such as the dynamo number N D . A comparison of the GALEX NUV and FUV brightness estimates with the activity parameters of the stars suggests that younger, more rapidly rotating active stars are brighter in the NUV, and that the FUV flux grows and the difference of the FUV and NUV brightnesses decreases with increasing spottedness S.
      PubDate: 2017-02-01
      DOI: 10.1134/s1063772917010036
      Issue No: Vol. 61, No. 2 (2017)
       
  • Photometric period and rotational brightness modulation of V833 Tau
    • Authors: N. I. Bondar’
      Pages: 130 - 137
      Abstract: Photometric data covering 1994–2009, obtained at the Crimean Astrophysical Observatory or retrieved from the ASAS and SuperWASP catalogs, were used to analyze the brightness variations of the rapidly rotating star V833 Tau, whose activity level is close to saturation. Combined with previously published results, these data represent for the first time all stages in the development of the star’s 19- year activity cycle. The photometric period and rotational-modulation amplitude for different epochs are determined, and the qualitative pattern of the spots is considered. The photometric period is close to the orbital period, but always exceeds it, indicating that surface inhomogeneities are located far from the equatorial plane. With the high spottedness of the star, reaching 28% at the cycle maximum, the rotationalmodulation amplitude is 0.05−0.1 m , and increases during the growth and decline phases of the 19-year cycle. The rotational modulation is due to spots with higher latitudes than in the case of the Sun, and concentrating on active longitudes.
      PubDate: 2017-02-01
      DOI: 10.1134/s1063772917010024
      Issue No: Vol. 61, No. 2 (2017)
       
  • Properties of the distribution of azimuthal magnetic field in a plasma
           flow during laboratory simulations of astrophysical jets in a plasma-focus
           installation
    • Authors: K. N. Mitrofanov; V. I. Krauz; V. V. Myalton; V. P. Vinogradov; A. M. Kharrasov; Yu. V. Vinogradova
      Pages: 138 - 152
      Abstract: The results of laboratory simulations of astrophysical jets are presented. Plasma flows generated in the PF-3 plasma-focus installation of the NRC “Kurchatov Institute” and propagating to distances substantially exceeding their transverse dimensions are studied. It is shown usingmagnetic probes that the plasma flow propagates with a frozen-in magnetic field. The resulting radial distribution of the azimuthal magnetic field corresponds well to the distribution created by a longitudinal current of ~10 kA flowing in a region with a radius of 1–2 cm near the axis. Structures associated with return currents are observed at the periphery of the flow. The magnetic field decays rapidly as the flow propagates along the axis. Nevertheless, the leading lobe of the plasma flow is preserved to substantial distances in a neon discharge, possibly due to radiative cooling of the plasma.
      PubDate: 2017-02-01
      DOI: 10.1134/s1063772917020032
      Issue No: Vol. 61, No. 2 (2017)
       
  • Results of tracking a spacecraft in the vicinity of the L2 libration point
           of the Sun–Earth system
    • Authors: I. V. Korobtsev; V. E. Goryashin; M. V. Eselevich
      Pages: 153 - 159
      Abstract: The launch of the Spektrum-Roentgen-Gamma (SRG) international orbiting astrophysical observatory is planned for the near future. It is planned tomaneuver SRGinto the vicinity of the L2 libration point of the Sun–Earth system, where it will be kept in a quasi-stable orbit. The spacecraft orbit must be maintained in order to carry out the scientific program of the project, which requires obtaining information about the current parameters of its motion. With the aim of developing methods for making optical measurements and estimating the required volume of measurement data and their accuracy, observations of the Gaia spacecraft, which is located in the vicinity of L2, were made at the Sayan Observatory in 2014–2015. The results of observations of the Gaia spacecraft on the 1.6-m infrared telescope of the Sayan Observatory are presented. The measured brightness of the spacecraft was 20.7–22m, which is close to the limiting magnitude of the telescope. The accuracy of these astrometric measurements was about one arcsecond. Possibilities for obtaining accurate astrometric data for the SRG spacecraft in orbit in the vicinity of L2 are discussed, as well as the required observing conditions and the volume of measurement data required for adequate prediction of the spacecraft motion.
      PubDate: 2017-02-01
      DOI: 10.1134/s1063772917010048
      Issue No: Vol. 61, No. 2 (2017)
       
  • Chandler oscillations of the Earth’s pole in the presence of
           fluctuational dissipative perturbations
    • Authors: Yu. G. Markov; V. V. Perepelkin; L. V. Rykhlova; A. S. Filippova
      Pages: 160 - 168
      Abstract: Effects of fluctuational dissipative perturbations on the Earth’s polar motion due to random components of the centrifugal potential are studied using a numerical-analytical approach. A combined model for the polar fluctuations is used to take into account stochastic components of the polar tides. Fluctuations excited at frequencies close to the Chandler frequency are analyzed using observations of sea level and the gravitional acceleration. Equations describing the correlation characteristics of the polar motions are presented.
      PubDate: 2017-02-01
      DOI: 10.1134/s1063772917020020
      Issue No: Vol. 61, No. 2 (2017)
       
  • Detection of sources of periodic radio emission with the Large Phased
           Array of the Lebedev Physical Institute
    • Authors: A. E. Rodin; V. V. Oreshko; V. A. Samodurov
      Pages: 30 - 37
      Abstract: A method for searching for new periodic radio sources is described. The method is based on the spectral analysis of data from daily monitoring of the sky on the Large Phased Antenna (LPA) of the Pushchino Radio Astronomy Observatory at 111 MHz in a 2.5-MHz band. The 96-beam directivity pattern of the LPA is used. The signal is received in six 0.42-MHz frequency channels with a sampling rate of 0.1 s. The duration of the processed survey is four months. The particulars of detecting periodic sources with the LPA are considered. In total, 16 such radio sources have been detected, for which equatorial and Galactic coordinates, periods, and dispersion measures are given.
      PubDate: 2017-01-01
      DOI: 10.1134/s1063772917010073
      Issue No: Vol. 61, No. 1 (2017)
       
  • High-velocity stars as a result of encounters between stars and massive
           binary black holes in galactic nuclei
    • Authors: S. V. Zhuiko; V. V. Orlov; K. S. Shirokova
      Pages: 47 - 52
      Abstract: Numerical simulations of the motions of stars in the gravitational fields of binary black holes with various component mass ratios have been carried out. Two models are considered: (1) the two-body problem with two fixed centers; (2) the general three-body problem. The first model is applicable only over short times Δt ≫ T, where T is the period of the binary system. The second model is applicable at all times except for during close encounters of stars with one of the binary components, r ≤ 0.00002 pc, where r is the distance from the star to the nearer black hole. In very close passages, relativistic corrections must be taken into account. Estimates of the probability of formation of high-velocity stars as a result of such interactions are obtained. It is shown that this mechanism is not suitable for the nucleus of our Galaxy due to the probable absence of a second massive black hole in the central region of the Galaxy.
      PubDate: 2017-01-01
      DOI: 10.1134/s1063772916120076
      Issue No: Vol. 61, No. 1 (2017)
       
  • Regularities in the response of spectral lines to small perturbations in
           physical quantities in the photosphere
    • Authors: S. G. Mozharovskii
      Pages: 70 - 73
      Abstract: Numerical simulations are used to establish a number of dependencies between small perturbations in physical quantities in the photosphere and small variations in the Stokes profiles of spectral lines. A perturbation of any physical quantity in the model photosphere shifts every point in a line profile in the direction perpendicular to the tangent to the profile at that point. The actions on the wing of a spectral line of perturbations in the magnetic field and radial velocity are equivalent for a particular ratio of these perturbations (if the line is fully split in the magnetic field). If the response of part of a line wing is considered as a shift in wavelength, the area under the curve representing the response to perturbations in the magnetic field and radial velocity has a simple physical meaning.
      PubDate: 2017-01-01
      DOI: 10.1134/s1063772917010061
      Issue No: Vol. 61, No. 1 (2017)
       
  • Filaments and the underlying surface from He I and H α line
           observations
    • Authors: E. A. Baranovskii; N. N. Stepanyan; V. P. Tarashchuk; N. I. Shtertser
      Pages: 74 - 79
      Abstract: Bright bands are observed along filaments in the He I 1083 nm line, while both bright and dark bands are observed along Hα 656.3 nm filaments. The range of brightness variations near He I filaments is 1.005–1.10 times the unperturbed brightness, with an average of 1.031 ± 0.01, while this range is 0.91–1.5 times the unperturbed brightness for Hα filaments. The physical state of the matter in these bands is investigated. Computations of the band brightness have been carried out for various chromospheric models, aimed at explaining the observed features of the bands. Two types of models are considered: with temperature or density variations in the upper chromosphere, and with temperature variations in the middle and lower chromosphere. In the first type of model, the brightness in the He I line is changed, but the Hα brightness is not. In the second type of model, only the Hα brightness is changed. Using the variations of the chromospheric parameters and both types of models, we obtained various combinations of band brightnesses in the He I line and in Hα. The brightnesses of regions were estimated by calculating the profiles of the He I and Hα lines in the corresponding models in a non-LTE approximation. A comparison of the observed and calculated quantities indicates that the enhancement in the brightness in the He I line is due to a decrease in temperature or density in the upper chromosphere (where the temperatures are about 10 000–24 000 K). The enhancement and dimming of the brightness in Hα are due to an increase or decrease of the temperature in the middle and lower chromosphere (where the temperatures are 6000–9000 K) by 800–1000 K. The dependence of the band brightness on distance from the center of the solar disk is also considered. The brightness in the He I line increases from the center to the limb by 2–4%. Computations of the center–limb brightness variaions correspond to the observed results.
      PubDate: 2017-01-01
      DOI: 10.1134/s1063772916120039
      Issue No: Vol. 61, No. 1 (2017)
       
 
 
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