Abstract Details
| Name: Gayathri Viswanath Affiliation: Christ University Conference ID: ASI2018_1767 Title : Estimation of Black Hole mass of a sample of narrow line Seyfert 1 galaxies Authors and Co-Authors : C.S.Stalin, Indian Institute of Astrophysics, Bangalore S.B.Gudennavar, Christ University, Bangalore Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : Narrow line Seyfert 1 (NLSy1) galaxies are a peculiar class of active galactic nuclei that are characterised by smaller full width at half maximum (FWHM) of the Hβ emission line compared to typical broad line Seyfert 1 galaxies (BLSy1). They are known to have small back holes (BH) weighing around 10^6 solar mass. Our knowledge of them having low BH mass has gained criticism after the detection of gamma-ray emission from less than a dozen NLSy1 galaxies by the Fermi Gamma-ray Space Telescope. Recent spectropolarimetric observations using the Very Large Telescope of one of the gamma-ray emitting NLSy1 galaxies, PKS 2004−447 gave direct evidence for the presence of broad emission lines in polarization, and consequently led to the estimation of a large BH mass than what was known earlier for this source. This observational finding has brought to focus the shortcomings in the BH masses available for NLSy1 galaxies. We are carrying out a systematic investigation of modelling the broad band spectral energy distribution of a large sample of about 10,000 NLSy1 galaxies to estimate their BH masses. The masses thus determined will be compared with the BH masses known for them based on single epoch spectral fits. The ongoing analysis once completed will be a consistency check on our present knowledge on the low BH mass nature of NLSy1 galaxies. Details of the work will be presented in the meeting. |