Abstract Details

Name: BRYAN RITHESH MIRANDA
Affiliation: BANGALORE UNIVERSITY
Conference ID: ASI2020_306
Title : UV Continuum study of NGC 3516 a strongly variable SB0 Seyfert I galaxy
Authors and Co-Authors : Author: Bryan R. Miranda Co-Author: Vedavathi P. and Vijayakumar H. Doddamani
Abstract Type : Poster
Abstract Category : Extragalactic Astronomy
Abstract : Active Galactic nuclei (AGN) is a compact highly luminous region (LBol > 1042 erg/s) present at the centre of a galaxy. These are the most luminous persistent sources of electromagnetic (EM) radiation in the universe and are observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. Since these sources emit radiations in all parts of the EM radiation, multiwavelength studies of AGN or active galaxies are very much necessary to understand the physical mechanisms responsible for emission of copious amount of radiation. It is observed that most of the AGNs are variable in their continuum and line fluxes with wide ranging timescales and amplitudes. In this paper we present the results from the analysis of the UV continuum flux variability observed in NGC 3516, a bright and strongly variable SB0 Seyfert I galaxy using long term spectroscopic observational data from International Ultraviolet satellite (IUE). IUE has made very successful observations of NGC 3516 from its launch in 1978 till 1995, with more number of observations in the year 1993. We present our results on the continuum variability amplitudes characterized by both relative variability amplitudes (Rmax) and F-variance (F-var) parameters. We have chosen the continuum windows as 1330-1370 Å, 1440-1460 Å, 1690-1730 Å, 1775-1825 Å, 2400-2450 Å, 2600-2650 Å, 2850-2900 Å and 3000-3050 Å and have obtained the Rmax & F-var values as 62.3, 52.18, 42.91, 59.92, 4.57, 5.46, 5.08 and 6.29 & 1.22, 1.10, 1.12, 1.30, 0.42, 0.48, 0.50 and 0.55 respectively. Without the observations in the year 1995, these are the following Rmax & F-var values for the given continuum windows 9.05, 8.19, 6.18, 8.39, 4.57, 5.46, 5.08 and 6.29 & 0.43, 0.41, 0.39, 0.46, 0.42, 0.48, 0.50 and 0.55 respectively. Additionally we have found very interesting continuum variability signatures for the observations in the years 1993 and 1995. It is seen that in the observations year 1995 the Rmax and F-var are the highest in comparison to observations in 1993.