Abstract Details
| Name: Dr Vijayakumar H Doddamani Affiliation: Bangalore University, Bangalore, karnataka Conference ID: ASI2018_1027 Title : An intensive monitoring study of Seyfert-1 galaxy NGC 7469 using IUE Authors and Co-Authors : Vedavathi. P Department of Physics, Bangalore University, Bangalore-560056 Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : Active galaxies exhibit continuum and line rapid variabilities over different time-scales ranging from a few minutes in X-rays to several days in UV and optical regions. In this paper, we present our results on the UV variability study of the Seyfert 1 galaxy NGC 7469 observed intensively by IUE satellite during June 10 to July 29, 1996 at nearly regular intervals of time. The minimum interval of observation has been about 3- 4 hours. We have found three major events of flux maxima separated nearly by 14 -16 days and the continuum flux has varied by an factor of 1.5 approximately at 1325 Å, 1475 Å and 1655 Å. The Lyα, Si IV C IV, C III] and Mg II lines also exhibited bearing a good correlation with the underlying continuum. We found characteristic period of variability neither in continuum nor in the emission lines from this intense observational campaign of NGC 7469. Lyα emission line has been found to have variable intrinsic absorption possible attributable to line of sight gas out flows. We find the CIV / CIII] line ratio to be ~ 2-4, typical of a Seyfert galaxy. The observed relatively higher amplitude variability in C IV than C III] line is indicative of the stratification of BELR region in active galaxies. These observations results provide new constraints on the theoretical photoionization models of the central regions of active galaxies. We explore the possibilities by which these observations can be reconciled with theoretical models. A detailed discussion on the implications of the results and the need for the future observations with higher temporal resolution is presented in this paper. Keywords: Seyfert 1 galaxy, NGC 7469, line flux, continuum flux, variability time-scale --------------------------------------------------------------------------------------------------------------------- *Corresponding author: drvkdmani@gmail.com |