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Browsing by Subject "AGN"

Browsing by Subject "AGN"

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  • ASTROSAT observations: complementary studies from ground 
    Sreekumar, P (Astronomical Society of India, 2005-06)
    Since the advent of the satellite era, X-ray astronomy and UV astronomy have advanced tremendously. The discovery of intense X-ray emission from accreting compact objects has permitted very detailed timing and spectral ...
  • A comparative study of the intra-night optical variability of powerful AGNs 
    Stalin, C. S; Gopal-Krishna; Sagar, R; Wiita, P. J (Astronomical Society of India, 2002-09)
    In order to address a currently much debated issue, we are carrying out a systematic search for intra-night optical micro-variability in major classes of powerful (M'II ~ -23.0 mag) active galactic nuclei (AGNs). Our ...
  • Dual Active Galactic Nuclei in Nearby Galaxies 
    Mousumi Das; Rubinur, K; Preethi, K; Varghese, A; Novakkuni, N; James, A (Societe Royale des Sciences de Liege, 2018-04)
    Galaxy mergers play a crucial role in the formation of massive galaxies and the buildup of their bulges. An important aspect of the merging process is the in-spiral of the supermassive black-holes (SMBHs) to the centre ...
  • Galaxy interactions, and the starburst galaxies - AGN connection. 
    Jog, C. J (Astronomical Society of India, 1995)
    Starbursts and Active Galactic Nuclei (AGN) are observed to preferentially occur in interacting or barred field galaxies. Galaxy interactions cause gas infall from the galactic disks, which may lead to the triggering of a ...
  • Monitoring of AGNs for variability from MIRO 
    Baliyan, K. S; Joshi, U. C; Ganesh, S (Astronomical Society of India, 2005-06)
    As a long term programme, a sample of blazars is being monitored from Mt Abu Infrared Observatory (MIRO). Blazars are the radio-loud AGNs with polarized, highly luminous and rapidly variable non-thermal continuum emission ...
  • Multi-band optical variability studies of Blazars 
    Aditi Agarwal (Societe Royale des Sciences de Liege, 2018-04)
    To search for optical variability on a wide range of timescales, we have carried out photometric monitoring of a dozen blazars. CCD magnitudes in B, V, R and I pass-bands were determined for > 10,000 new optical observations ...
  • Multiwavelength study of the variability in blazars 
    Baliyan, K. S (Astronomical Society of India, 2001)
    Blazars are the radio-loud AGNs with polarized, highly luminous and rapidly variable non-thermal continuum emission ranging from radio to ??rays, from a relativistic jet. These features are interpreted in terms of the ...
  • Observation of hard X-ray emission from extragalactic sources 3C 273 and NGC 5506 in 20-200 keV band 
    Manchanda, R. K (Astronomical Society of India, 2001)
    We report spectral measurements of the bright QSO 3C273 and the AGN source NGC 5506 made during a balloon flight experiment using high sensitivity scintillation counter telescope LASE, operating in the 20-200 keV energy ...
  • A polarization study of three blazars using uGMRT at ∼600 MHz 
    Baghel, J; Silpa, S; Kharb, P; Sebastian, B; Shastri, P (Indian Academy of Sciences, 2022-12)
    We present results from our radio polarimetric study with the upgraded giant metrewave radio telescope (uGMRT) at band 4 (550–850 MHz) of three blazars: radio-loud quasars 3C390.3, 4C71.07 and BL Lac object 1ES 2344+514. ...
  • Probing the central engine and environment of AGN using ARIES 1.3-m and 3.6-m telescopes 
    Chand, H; Rakshit, S; Jalan, P; Ojha, V; Srianand, R; Vivek, M; Mishra, S; Omar, A; Kumar, P; Joshi, R; Gopal Krishna; Kumar, R (Societe Royale des Sciences de Liege, 2018-04)
    : We discuss three long term observational programmes to probe the central engine and environment of active galactic nuclei (AGN) using the recently installed ARIES 1.3-m and 3.6-m telescopes. The first programme is on ...
  • Properties of Narrow line Seyfert 1 galaxies 
    Rakshit, S; Stalin, C. S; Chand, H; Zhang, X (Bulletin de la Societe Royale des Sciences de Liege, 2018-04)
    Narrow line Seyfert 1 (NLSy1) galaxies constitute a class of active galactic nuclei characterized by the full width at half maximum (FWHM) of the Hα broad emission line <2000 km s-1 and the flux ratio of [O III] to Hα ...
  • Starburst galaxies -- AGN connection: Theoretical scenario 
    Jog, Chanda J (Astronomical Society of India, 1993)
    Starburst galaxies are characterized by a very high central infrared luminosity of about 10/sup10/ - 10/sup12/ solar luminosity. This luminosity is attributed to a burst of formation of massive stars. The stellar radiation ...
  • Study of variability in BL Lac objects 
    Baliyan, K. S; Ganesh, S; Joshi, U. C; Shah, C. R; Vadher, N. M; Deshpande, M. R (Astronomical Society of India, 2001)
    We have monitored some of the BL Lac objects, such as OJ287, Mrk 421, Mrk 501 etc from Mt Abu Infrared Observatory, using optical photopolarimeter, CCD and NICMOS-3 IR array mounted at the Cassegrain focus of the 1.2 m ...

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