IIAP Publications: Recent submissions

  • The Influence of a Vertical Magnetic Field on Oscillations in an Isothermal Stratified Atmosphere. II. 
    Banerjee, D; Hasan, S. S; Christensen-Dalsgaard, J (University of Chicago Press, 1995-10)
    We examine the effect of a uniform vertical magnetic field on the modes of an isothermal stratified atmosphere. The present investigation is a continuation of earlier work by Hasan & Christensen-Dalsgaard in which this ...
  • Torsion, minimum time, string tension and its physical implications in cosmology 
    de Sabbata, Venzo; Sivaram, C (Springer, 1992-01)
    By introducing torsion in general relativity - that is physically considering the effect of the spin and linking the torsion to defects in the space-time topology - a minimum unit of time can be obtained. In this context ...
  • The X-ray spectrum of the superluminal quasar 1928 + 73 
    Ghosh, K. K; Soundararajaperumal, S (Blackwell Publishing, 1992-02)
    Exosat observations (0.1-10 keV) of the radio-loud quasar 1928 + 73, which displays superluminal motion, were made at four epochs between 1983/283 and 1984/009, and spectra of this source are obtained from the Exosat ...
  • Distribution of stars perpendicular to the plane of the Galaxy. II. 
    Chatterjee, S (EDP Sciences, 1995-06)
    We present here rigourous analytical solutions of the Boltzmann-Poisson equations concerning the distribution of stars perpendicular to the galactic plane. The number density of stars at the galactic disk is assumed to ...
  • On the eruption of prominences and disappearance of quiescent filaments 
    Singh, J; Gupta, S. S (Springer, 1995-05)
    We suggest the following heuristic model for the evolution of a quiescent filament. The middle part of the filament rises due to heating, while its ends remain anchored in the chromosphere; and a kink appears in the H alpha ...
  • Fading and variations in the spectrum of the central star of the very young planetary nebula SAO 244567 (Hen 1357). 
    Parthasarathy, M; Garcia-Lario, P; de Martino, D; Pottasch, S. R; Kilkenny, D; Martinez, P; Sahu, K. C; Reddy, B. E; Sewell, B. T (EDP Sciences, 1995-08)
    The optical spectrum of SAO 244567 obtained in 1971 shows that it was a post-AGB B1 or B2 supergiant at that time. It has turned into a planetary nebula (PN ) within the last 20 years. The IUE ultraviolet spectra obtained ...
  • BV photometry and Hα spectroscopy of the RS Canum Venaticorum binary UX Arietis. 
    Raveendran, A. V; Mohin, S (EDP Sciences, 1995-09)
    We present differential BV photometry of UX Ari obtained on 76 nights during 1989-94 and Hα spectroscopy obtained on 14 nights during the 1990-91 observing season. The migration of the phase of light minimum indicates a ...
  • Photometric study of the RS CVn binary DM Ursa Majoris 
    Mohin, S; Raveendran, A. V (EDP Sciences, 1992-03)
    Differential BV photometry of DM UMa obtained on 77 nights during the six observing seasons over the years 1984-90 is presented. The phases of the light minima observed during 1988-90 are found to be nearly the same. The ...
  • EXOSAT observations of the broad-line radio galaxy 3C 382 
    Ghosh, K. K; Soundararajaperumal, S (University of Chicago Press, 1992-04)
    Results are presented of numerous X-ray observations of the broad-line radio galaxy 3C 382 carried out with Exosat between 1983 and 1985, with emphasis on a major outburst of this galaxy in 1985. During the outburst, both ...
  • Spatio-temporal fluctuations in He I 10830 A line parameters - Evidence for spicule formation 
    Venkatakrishnan, P; Jain, S. K; Singh, J; Recely, F; Livingston, W. C (Springer Netherlands, 1992-03)
    The equivalent width, line depth, line width, and Doppler shift of the He i 10830 Å line were extracted from two time series of spectra. Scatter plots of time-averaged line depth, line width, and Doppler shifts, as well ...
  • Global modes constituting the solar magnetic cycle. I - Search for 'dispersion relations' 
    Gokhale, M. H; Javaraiah, J; Kutty, K. N; Varghese, B. A (Springer Netherlands, 1992-03)
    The spherical-harmonic-Fourier (SHF) analysis of the sun's magnetic field inferred from the Greenwich sunspot data is refined and extended to include the full length (1874-1976) of the data on the magnetic tape provided ...
  • X-ray spectrum of NGC 3783 - Detection of soft excess and an emission line 
    Ghosh, K. K; Soundararajaperumal, S; Kalai Selvi, M; Sivarani, T (EDP Sciences, 1992-02)
    Results of the X-ray (0.1-10 keV) spectral analysis of the Seyfert I galaxy, NGC 3783, which was observed with EXOSAT on three epochs between 1983 and 1985, are presented here. No low energy absorption, intrinsic to the ...
  • The Mauritius Radiotelescope 
    Golap, K; Issur, N. H; Somanah, R; Dodson, R; Modgekar, M; Sachdev, S; Shankar, N. Udaya; Sastry, Ch. V (Springer Netherlands, 1995-06)
    The Mauritius Radiotelescope (MRT) is a T-shaped array of helical antennas with a 2048 m EW arm and a 890 m South arm. The primary objective of the telescope is to produce a sky survey in the declination zone -15° to -65° ...
  • Probable binary open star clusters in the Galaxy. 
    Subramaniam, A; Gorti, U; Sagar, R; Bhatt, H. C (EDP Science, 1995-10)
    The existence of double/binary clusters in the Magellanic Clouds is fairly well established, whereas only one such pair, h + χ Persei, is known in the Galaxy. From the catalogues of open clusters of the Galaxy, we have ...
  • Galaxy dynamics with small computers: Some results on tidal interactions. 
    Kochhar, R. K; Namboodiri, P. M. S (Springer Netherlands, 1995-06)
    Numerical simulations with a small computer have been performed to investigate the tidal influence of a larger galaxy on a smaller companion. A criterion is developed for disruption of the satellite galaxy. The behaviour ...
  • The synthesis of Al-26 during combined hydrogen and helium-burning reactions 
    Goswami, A; Ramadurai, S; Duorah, H. L (Springer Netherlands, 1992-02)
    The synthesis of Al-26 during combined hydrogen and helium-burning processes in high temperature and density conditions is studied. The possible sites for these processes are believed to be the neutron star surfaces where ...
  • Distribution of ionized gas in X-ray bright early-type galaxies. 
    Singh, K. P; Bhat, P. N; Prabhu, T. P; Kembhavi, A. K (Springer, 1995-10)
    We report imaging observations of Hα+[N II] nebulosities in seven early type galaxies viz., NGC 1399, NGC 1600, NGC 2563, NGC 4203, NGC 4636, NGC 4753 and NGC 5044. These are primarily X-ray bright galaxies which are the ...
  • On the Large-Scale Diffuse Magnetic Field of the Sun 
    Dikpati, M; Choudhuri, A. R (Springer, 1995-10)
    Although the sunspots migrate towards the equator, the large-scale weak diffuse magnetic fields of the Sun migrate poleward with the solar cycle, the polar field reversing at the time of the sunspot maxima. We apply the ...
  • X-ray continuum with an iron emission line from the radio-quiet quasar PHL 909 
    Ghosh, K. K; Soundararajaperumal, S (University of Chicago Press, 1992-04)
    Results of the spectral analysis of the X-ray (0.1-10 keV) spectrum of the radio-quiet quasar, PHL 909, are presented. A spectrum of this quasar, which was observed on 1984/349, was obtained from the Exosat archives. ...
  • The role of Compton and Raman scattering in the quasar continuum 
    Gangadhara, R. T; Krishan, V (Blackwell Publishing, 1992-05)
    There are three ways in which an electromagnetic wave can undergo scattering in a plasma: (1) when the scattering of radiation occurs by a single electron, it is called Compton Scattering; (2) if it occurs by a longitudinal ...

Search DSpace


Browse

My Account