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Browsing by Author "Peraiah, A"

Browsing by Author "Peraiah, A"

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  • Limb Darkening due to the Incidence of a Parallel Beam of Radiation 
    Peraiah, A (Indian Institute of Astrophysics, Bangalore, 1983)
    We have investigated how the radiation is distributed from the centre to the limb when the atmosphere receives a parallel beam of radiation from infinity. We have considered a purely reflecting surface at the bottom of the ...
  • Line formation in spherical media with partial frequency redistribution. I - Solution of the line transfer 
    Peraiah, A (Kluwer Academic Publishers, 1978-09)
    The solution of line transfer with partial redistribution for an arbitrary (i.e., either stationary or moving) spherical medium is formulated in the framework of discrete space theory. The equation of line transfer for a ...
  • Line formation in spherical media with partial frequency redistribution. II - Expanding media with redistribution function R sub I 
    Peraiah, A (D. Reidel Publishing Co., 1979-07)
    Lines formed in a differentially expanding atmosphere have been calculated by using the angle averaged redistribution functionR I (Hummer, 1962). We have compared these lines, in a few cases, with those formed by complete ...
  • 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 ...
  • Linear polarization in close binaries 
    Parman, S. K; Peraiah, A (Nova Science Publishers Inc, 1993)
  • Lines formed in Rotating and Expanding Atmospheres 
    Peraiah, A (Indian Academy of Sciences, 1980-09)
    Spectral lines formed in a rotating and expanding atmosphere have been computed in the frame of the observer at infinity. Two kinds of velocity laws are employed: (i) a uniform radial velocity of the gas and (ii) velocity ...
  • Lines Formed in Slowly Expanding Thin Spherical Shell 
    Peraiah, A; Raghunath, G; Nagendra, K. N (Indian Institute of Astrophysics, Bangalore, 1980)
    We have investigated how an optically thin spherical shell with small velocities change the profiles and equivalent widths of the lines. We have employed several types of variations in density, velocity of expansion and ...
  • Numerical solution of the radiative transfer equation in a magnetized medium 
    Nagendra, K. N; Peraiah, A (Blackwell Publishing, 1985-05)
    A numerical method of solution based on the discrete space theory of radiative transfer as applied to the transfer problems in an anisotropic medium is discussed. Two simple applications, namely the scattering in the ...
  • On negative intensities in discrete space theory in spherical medium 
    Peraiah, A (Indian Institute of Astrophysics, 1978)
    The reasons for the occurrence of negative intensities are discussed. A method is described to obtain positive solution of radiative transfer equation in spherical symmetry in distance space theory by using frequency ...
  • On the Balmer progression in the expanding shell of Pleione 
    Peraiah, A (Indian Academy of Sciences, 1982-09)
    An attempt has been made to explain the Balmer progression in velocities seen in Pleione and other shell stars. Equations of conservation of mass and momentum are simultaneously solved with assumptions which simplify the ...
  • 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 ...
  • Optical depth effects on the formation of spectral lines in rotating and expanding spherical atmospheres 
    Peraiah, A; Raghunath, G; Nagendra, K. N (Indian Academy of Sciences, 1981)
    The effect of high optical depths and large rotational velocities on the spectral lines in rotating and radial expanding spherical shells is investigated. It is assumed that the outer radius of the shell is three times the ...
  • P Cygni type profiles 
    Peraiah, A; Srinivasa Rao, M (Indian Institute of Astrophysics, Bangalore, 1985-11)
    We have presented a series of P Cygni type profiles of special lines computed by employing different velocity laws of expansion in a spherically atmosphere. A comparison has been made with those of Beals classification. ...
  • Photon escape probabilities in expanding atmospheres 
    Peraiah, A; Rangarajan, K. E; Mohan Rao, D (Indian Academy of Sciences, 1981-03)
    A comparison of mean number of scatterings and escape probabilities has been made in isotropic scattering and dipole scattering by using the angle-averaged partial frequency redistribution functionR I. We have solved the ...
  • Polarization in binaries 
    Barman, S. K; Peraiah, A (Astronomical Society of India, 1991)
    Theoretical models are computed for estimating linear polarization from the extended dusty outer layers of the components of a close binary system whose surfaces are distorted by rotation and mutual tidal effects. ...
  • Polarization of continuum radiation in magnetic atmospheres 
    Nagendra, K. N; Peraiah, A (Kluwer Academic Publishers, 1984-09)
    A numerical solution is presented for the problem of continuum radiative transfer in a magnetoactive medium. The continuum opacities are calculated in the presence of a strong magnetic field (H = 10 MG) typical of magnetic ...
  • Principles of Invariance in Radiative Transfer 
    Peraiah, A (Kluwer Academic Publishers, 1999-01)
    We have reviewed the principle of invariance, its applications and its usefulness for obtaining the radiation field in semi-infinite and finite atmospheres. Various laws of scattering in dispersive media and the consequent ...
  • Radiation pressure in resonance lines 
    Peraiah, A (Indian Institute of Astrophysics, 1979-11)
    The effects of large scales gas motions on the radiation pressure in a resonance lines are investigated. We have assumed a medium with pure scattering together with emission in the continuum. A linear velocity law is ...
  • Radiation trensfer in fast moving fluids 
    Peraiah, A (Astronomical Society of India, 1990)
    Various factors influencing the formation of spectral lines are described, emphasizing the physics of stellar atmospheres. Broadening mechanisms, photon or partial frequency redistribution, the role of chemical species are ...
  • Radiative transfer effects due to curvature and expansion in a dusty planetary nebulae 
    Peraiah, A (International Astronomical Union, 1983)

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