IIA Institutional Repository

Browsing by Author "Ghosh, K. K"

Browsing by Author "Ghosh, K. K"

Sort by: Order: Results:

  • Optical Variability of BL Lacertae during the Major Outburst of 1997 
    Ghosh, K. K; Ramsey, B. D; Sadun, A. C; Soundararajaperumal, S; Wang, J (The American Astronomical Society, 2000-07)
    We have undertaken an investigation of recent flux variability in BL Lac. We present optical observations taken over 22 nights documenting major as well as minor outbursts. This has been combined, for purposes of multifrequency ...
  • Optical Variability of Blazars 
    Ghosh, K. K; Ramsey, B. D; Sadun, A. C; Soundararajaperumal, S (The American Astronomical Society, 2000-03)
    In this paper we show the results of our monitoring the flux variability of 15 blazars, within the redshift range of 0.07-2.06, all with a visual magnitude range between 14 and 20 mag. Because blazars have displayed ...
  • Origin of MeV gamma-ray emissions from blazars 
    Ghosh, K. K; Ramsey, B. D; Sivaram, C (Elsevier Science B. V, 1999-06)
    We have developed a model for MeV emission from blazars that involves the production of MeV gamma-rays through Inverse Compton (IC) scattering of electrons in the blob of a jet, with the UV photons of the accretion disk. ...
  • Physics of the phase changes of Be stars 
    Ghosh, K. K (International Astronomical Union, 1994)
    Based on Spectrosopic observations of more than 100 Be stars, we present the reuslts of the phase changes of Be stars.
  • Probability for the formation of complex ring molecules in interstellar medium and their detection proposal 
    Ghosh, K. K (International Astronomical Union, 1987)
    The pathways for the formation and destruction processes of ring molecules in the interstellar medium are proposed and their abundances are calculated under steady state conditions. The calculated abundances are of the ...
  • Quenching of NO2 continuum by NO, H2O & CH4 
    Ghosh, K. K (Publications & Information Directorate, CSIR, 1984-10)
    The K/A ratio, where K is the quenching rate coefficient of NO2 continuum by NO2, H2O and CH4 and A is the transition probability of NO2 continuum, has been measured using flowing afterglow method. The obtained values are ...
  • Rapid continuum level variability in Be stars earlier than B2 
    Ghosh, K. K (American Astronomical Society, 1990-05)
    H-alpha profiles for 12 Be stars and four standard stars were obtained on six nights in January and February, 1988, in order to search for rapid spectral variability in these stars. The results show that the Be stars earlier ...
  • Rapid H-alpha variability in Phi Persei 
    Ghosh, K. K; Sanjeevkumar, T; Jaykumar, K; Kuppuswamy, K; Rosario, M. J (Astronomical Society of the Pacific, 1988-06)
    A search for rapid variability of H-alpha with a time resolution from 30 to 45 seconds is performed for Phi Per. In total, 42 spectra in H-alpha were obtained during three nights. Results show the presence of rapid irregular ...
  • Rapid simultaneous observations of Fe II and Balmer emission lines of X OPH 
    Ghosh, K. K; Jayakumar, K (D. Reidel Publishing Co., 1988-02)
    Sudden brightening of Fe II and Balmer (Hβ and Hα) lines of X Oph was observed on 28 - 29 May, 1986. Equivalent width of Fe II and Hβ lines increased by a factor of two and that for Hα line by a factor of four, during the ...
  • Rapid variations of H-alpha emission strength of eight Be stars 
    Ghosh, K. K (Kluwer Academic Publishers, 1988-08)
    Rapid observations of H profiles of eight Be stars have been obtained and it is found that rapid (in a time-scale of 4 to 6 minutes) and irregular variations of total emission strength of H line are present in these stars. ...
  • Recent mass loss episode of the Be Star omicron And 
    Ghosh, K. K; Jaykumar, K; Rosario, M. J; Appakutty, M (Konkoly Observatory, 1986-05)
  • Recent onset of an outburst in mu centauri 
    Ghosh, K. K; Velu, C; Kuppuswamy, K; Jaykumar, K; Rosario, M. J (Konkoly Observatory, 1987-08)
  • Search for rapid H-alpha variability studies in Be stars - 28 Eri, X Ophiuchi, 66 Ophiuchi and Pi Aquarii 
    Ghosh, K. K (EDP Sciences, 1988-10)
    In order to search for rapid Hα variability in Be stars, a series of Hα profiles were observed on a time scale of few minutes for 28 Eri, X Oph, 66 Oph and π Aqr. In total, 95 and 54 Hα profiles were obtained for the program ...
  • Search for rapid spectral variability in Be stars - Alpha Columbae, Rho Carinae and Eta Centauri 
    Ghosh, K. K; Pukalenthi, S; Jaykumar, K; Kuppuswamy, K; Sanjeevkumar, T; Muniandi, A (European Southern Observatory, 1990-03)
    A series of H-alpha profiles (in total 1006 spectra in the H-alpha region) with the time resolution around 45 s were obtained on six nights between January 29 and February 7, 1988, to search for rapid spectral variability ...
  • Search for rapid spectral variability in Psi(9) Aurigae 
    Ghosh, K. K (Astronomical Society of the Pacific, 1989-09)
    Observations of Psi(9) Aur on five nights between January 29 and February 3, 1988 were conducted as part of a search for rapid spectral variability in Be stars. In addition, a series of H-alpha profiles with a time resolution ...
  • Search for rapid V/R variability in Eta CEN 
    Ghosh, K. K (Royal Astronomical Society, 1989-10)
    In order to search for rapid V/R variability in the Be star, Eta Cen, a series of H-alpha profiles of this star were observed on three nights between May 28 and June 3, 1986. A method of estimating the standard deviation ...
  • Simultaneous infrared and H-alpha measurements of Be stars 
    Apparao, K. M. V; Tarafdar, S. P; Verma, R. P; Iyengar, K. V. K; Ghosh, K. K (Indian Academy of Sciences, 1993)
    The observed infrared excess in Be stars is usually interpreted as free-free and free-bound emission from a hot gas envelope around the Be star. This hot gas should also emit H-alpha line radiation. Earlier observations ...
  • Simultaneous Radio and Hα Observations of Be-Stars 
    Rengarajan, T. N; Tarafdar, S. P; Ghosh, K. K (European Southern Observatory, 1990-03)
    We have observed 18 Be stars in the radio continuum at 2cm wavelength with the VLA on 7th February 1987. We observed 12 of the stars the same night in the optical using an H alpha filter and the rest subsequently. No radio ...
  • SN 1993J in M 81: Optical photometry and spectrophotometry during the first two months 
    Prabhu, T. P; Mayya, Y. D; Singh, K. P; Kameswara Rao, N; Ghosh, K. K; Mekkaden, M. V; Pati, A. K; Raveendran, A. V; Reddy, B. E; Sagar, R; Subramaniam, A; Surendiranath, R (The European Southern Observatory, 1995-03)
    CCD photometric and spectrophotometric data on the type IIb supernova 1993J in M 81 (NGC 3031) obtained from Vainu Bappu Observatory, Kavalur, during the first two months since the outburst are reported. The evolution of ...
  • Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 6: Variability of NGC 3783 from ground-based data 
    Stirpe, G. M; Winge, C; Altieri, B; Alloin, D; Aguero, E. L; Anupama, G. C; Ashley, R; Bertram, R; Calderon, J. H; Catchpole, R. M; Corradi, R. L. M; Covino, E; Dottori, H. A; Feast, M. W; Ghosh, K. K; Hutton, R. Gil; Glass, I. S; Grebel, E. K; Jorda, L; Koen, C; Laney, C. D; Maia, M; Marang, F; Mayya, Y. D; Morrell, N; Nakada, Y; Pastoriza, M. G; Pati, A. K; Pelat, D; Peterson, B. M; Prabhu, T. P; Roberts, G; Sagar, R; Salamanca, I; Sekiguchi, K; Storchi-Bergmann, T; Subramaniam, A; Van Winckel, H; Van Wyk, F; Villada, M; Wagner, R. M; Whitelock, P. A; Winkler, H; Clavel, J; Dietrich, M; Kollatschny, W; O'Brien, P. T; Perola, G. C; Recondo-Gonzalez, M. C; Rodriguez-Pascual, P; Santos-Lleo, M (The American Astronomical Society, 1994-04)
    The Seyfert 1 galaxy NGC 3783 was intensely monitored in several bands between 1991 December and 1992 August. This paper presents the results from the ground-based observations in the optical and near-IR bands, which ...

Search DSpace

Browse

My Account