IIA Institutional Repository

Browsing by Subject "Galaxies:active"

Browsing by Subject "Galaxies:active"

Sort by: Order: Results:

  • A Comparative Study of Intra-night Optical Micro-variability of High Luminosity AGN Classes 
    Stalin, C. S (Astronomical Society of India, 2003)
    This thesis explores mainly the problem of the radio loudness dichotomy in quasars. This is addressed by carrying out an extensive search for intra-night optical variability (INOV) in seven sets of optically luminous ...
  • Discovery of a new NLQSO: RX J1334.2+3759 
    Dewangan, G. C; Singh, K. P; Jones, L. R; McHardy, I. M; Newsam, A. M; Mason, K. O (Astronomical Society of India, 2001)
    A new narrow-line QSO, RX J1334.2+3759, has been identified at a redshift of 0.3858. The QSO has intrinsic soft X-ray luminosity ~ 2.8 x 1044 erg s-1. Soft X-ray emission from the QSO is highly variable. Rapid variability ...
  • Intranight optical monitoring of optically selected bright quasars 
    Sagar, R; Gopal-Krishna; Wiita, P. J (Royal Astronomical Society, 1996-08)
    As part of an ongoing programme to search for intranight optical variations, we report results for six radio-quiet and one radio-moderate, but all optically bright and luminous, quasi-stellar objects (QSOs), using the ...
  • Morphologies in megaparsec-size powerful radio galaxies 
    Subrahmanyan, R; Saripalli, L; Hunstead, R. W (Royal Astronomical Society, 1996-03)
    We present radio images with the Australia Telescope of a sample of powerful radio galaxies. The observations were designed to be sensitive to the largest-scale structures in the radio sources. The morphologies are ...
  • Narrow-line Seyfert 1 galaxies 
    Dewangan, G. C (Astronomical Society of India, 2001)
    Narrow-line Seyfert 1 (NLS1) galaxies form a distinct subclass of Seyfert 1 galaxies. Optical spectroscopic and X-ray spectral and timing results on NLS1 and the plausible underlying physical parameters thought to be ...
  • Polarization Asymmetry in CSS Sources 
    Saikia, D. J; Gupta, N (Astronomical Society of India, 2003)
    We show that the compact steep spectrum sources are more asymmetric in the polarization of the outer lobes compared with the more extended ones. This could be due to interaction of the jets with infalling material, which ...
  • Radio Study of a Superwind-galaxy: NGC1482 
    Hota, A; Saikia, D. J (Astronomical Society of India, 2003)
    We present GMRT and VLA observations of the superwind galaxy, NGC1482, which has been discovered to have a remarkable hour-glass shaped optical emission line outflow on both sides of the galactic disk. The central region ...
  • Soft X-ray properties of a complete sample of QSOs 
    Dewangan, G. C; Singh, K. P (Astronomical Society of India, 2001)
    In order to study systematically the soft X-ray emission of AGNs, we have analyzed ROSAT PSPC spectra of 22 QSOs. The QSOs form a complete sample with soft X-ray flux ??1.4 x 10-14 erg cm-2 s-1 in the energy band of 0.1-2.0 ...
  • A Study of Giant Radio Galaxies 
    Konar, C; Saikia, D. J; Ishwara-Chandra, C. H; Kulkarni, V. K (Astronomical Society of India, 2003)
    Multi-frequency radio observations have been made of a sample of 17 giant radio galaxies, many of whose structures were not well determined earlier. These sources were observed with the VLA D- and B/C arrays at C and L ...
  • X-ray polarization observations of IC 4329A with IXPE: Constraining the geometry of the X-ray corona 
    Pal, Indrani; Stalin, C. S; Chatterjee, Rwitika; Agrawal, Vivek K (Indian Academy of Sciences, 2023-12)
    X-ray polarimetry is a powerful tool to probe the geometry of the hot X-ray corona in active galactic nuclei (AGN). Here, we present our results on the characterisation of the X-ray polarization of the radio-quiet Seyfert-type ...

Search DSpace

Browse

My Account