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Browsing by Author "Varghese, B. A"

Browsing by Author "Varghese, B. A"

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  • Line Profiles in an Expanding Spherical Medium 
    Peraiah, A; Srinivasa Rao, M; Varghese, B. A (Indian Institute of Astrophysics, Bangalore, 1986)
    We have applied the discrete space theory of radiative with the integral operator technique to calculate the spectral line profiles formed in a spherically symmetric expanding stellar atmospheres. We calculated the source ...
  • Magnetic Activity and the Enhanced 5303 Ã Emission in Solar Active Regions 
    Ramesh, K. B; Nagabhushana, B. S; Varghese, B. A (Springer, 2001-03)
    Analysis of the intensity maps of Fexiv emission at λ=5303 Å obtained from the observations of ground-based coronagraphs during the sunspot minimum period 1985 and 1986 shows the persistent presence of localized strong ...
  • On the coronal lines 5303 A and 6374 A 
    Peraiah, A; Varghese, B. A (Springer, 1989-06)
    Theoretical calculations of the observed coronal emission line profiles of Fe XIV (5303 A) and Fe X (6374 A) ions, which are observed at the time of total solar eclipse, are presented. Baumbach's relation of electron density ...
  • Radiative transfer equation in spherical symmetry 
    Peraiah, A; Varghese, B. A (American Astronomical Society, 1985-03)
    A numerical solution of the radiative transfer equation in spherically symmetric geometry is presented using integral operators within the framework of the discrete space theory and expressing the specific intensity in ...
  • Radiative transfer equation in spherically-symmetric non-scattering media 
    Peraiah, A; Varghese, B. A (D. Reidel Publishing Co., 1984-12)
    The equation of radiative transfer in spherically symmetric shells with arbitrary internal sources is solved. The equation of transfer is integrated on a discrete grid of angle and radius. The size in angle coordinates is ...
  • Radiative Transfer Models of Dust Shells Around Post-AGB Stars 
    Surendiranath, R; Parthasarathy, M; Varghese, B. A (Springer, 2002-09)
    We present a radiative transfer analysis of circumstellar dust shells around the Post-AGB stars HD 179821, HD 56126, HD 101584 and early R star HD 100764, using the code DUSTY. Parameters like mass-loss, shell inner radius, ...
  • Radiative transfer with Compton scattering in spherically symmetric shells 
    Peraiah, A; Varghese, B. A (Astronomical Society of Japan, 1990)
    The radiative transfer equation with Compton scattering is solved for spherically symmetric shells. The purpose of the study is to determine how gamma rays or X-rays change their energies and how they become reflected and ...
  • Reflection effect in close binaries: effects of reflection on spectral lines 
    Srinivasa Rao, M; Varghese, B. A (Springer, 2014-02)
    Reflection effect phenomenon is studied on the formation of spectral lines in a close binary system when primary component has an extended atmosphere and the secondary component is a point source. Irradiation effect is ...
  • Simultaneous solution of Kompaneets equation and radiative transfer equation in the photon energy range 1–125 keV 
    Peraiah, A; Srinivasa Rao, M; Varghese, B. A (Elsevier, 2011-03)
    Radiative transfer equation in plane parallel geometry and Kompaneets equation is solved simultaneously to obtain theoretical spectrum of 1–125 keV photon energy range. Diffuse radiation field are calculated using ...
  • Solution of radiative transfer equation with spherical-symmetry in partially scattering medium 
    Peraiah, A; Varghese, B. A (D. Reidel Publishing Co., 1985-01)
    The authors have solved the equation of radiative transfer in spherical symmetry with scattering and absorbing medium. They have set the albedo for single scattering to be equal to 0.5. They have set the Planck function ...
  • Stellar Winds in O and B Type Stars: Hydrogen Atmosphere 
    Peraiah, A; Varghese, B. A (Indian Institute of Astrophysics, Bangalore, 1993)
    We present the results of calculations of radiation driven stellar winds O-B stars. The equations of conservation of mass and momentum are solved self consistently with the equation of line transfer. The influence of ...
  • Temperature variability in X-ray bright points observed with Hinode/XRT 
    Kariyappa, R; DeLuca, E. E; Saar, S. H; Golub, L; Dam´e, L; Pevtsov, A. A; Varghese, B. A (EDP Science, 2011-02)
    Aims. Our aim is to investigate the variability in the temperature as a function of time among a sample of coronal X-ray bright points (XBPs). Methods. We analysed a 7-hour (17:00 UT - 24:00 UT) long time sequence of ...
  • Temporal and spatial variations of the quiet upper chromosphere from SOHO/SUMER observations of hydrogen Lyman lines 
    Kariyappa, R; Varghese, B. A; Curdt, W (EDP Sciences, 2001-08)
    We have analyzed a time series of spectra in the hydrogen Lyman lines and the Lyman continuum obtained by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on the SOlar Heliospheric Observatory ...
  • Theoretical study of irradiation effects in close binaries 
    Srinivasa Rao, M; Varghese, B. A (Astronomical Observatory, 2009-06)
    The effect of irradiation is studied in a close binary system assuming that the secondary component is a point source, moving in a circular orbit. The irradiation effects are calculated on the atmosphere of the primary ...
  • Unveiling Vela – time variability of Na I D lines in the direction of the Vela supernova remnant 
    Kameswara Rao, N; Muneer, S; Lambert, D. L; Varghese, B. A (Oxford University Press on behalf of the Royal Astronomical Society, 2016-01-21)
    High-resolution spectral profiles of Na I D lines from the interstellar medium towards 64 stars in the direction of the Vela supernova remnant are presented. This survey conducted mostly between 2011 and 12 complements an ...

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