Variable X-ray reflection from 1H~0419–577

Дата и время публикации : 2013-07-23T20:01:59Z

Авторы публикации и институты :
Main Pal
Gulab C. Dewangan

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: accepted for publication in MNRAS, 13 pages including 7 figures
Первичная категория: astro-ph.HE

Все категории : astro-ph.HE

Краткий обзор статьи: We present detailed broadband X-ray spectral variability of a Seyfert 1 galaxy 1H~0419–577 based on an archival suzaku{} observation in July 2007, a new suzaku{} observation performed in January 2010 and the two latest xmm{} observations from May 2010. All the observations show soft X-ray excess emission below $2kev$ and both suzaku{} observations show a hard X-ray excess emission above $10kev$ when compared to a power-law. We have tested three physical models — a complex partial covering absorption model, a blurred reflection model and an intrinsic disk Comptonization model. Among these three models, the blurred reflection model provided statistically the best-fit to all the four observations. Irrespective of the models used, the soft X-ray excess emission requires contribution from a thermal component similar to that expected from an accretion disk. The partial covering absorption model results in a nonphysical high temperature ($kT_{in} sim 100ev$) for an accretion disk and is also statistically the worst fit among the three models. 1H~0419–577 showed remarkable X-ray spectral variability. The soft X-ray excess and the power-law both became weaker in January 2010 as well as in May 2010. A moderately broad iron line, detected in July 2007, is absent in the January 2010 observation. Correlated variability of the soft X-ray excess and the iron $Kalpha$ line strongly suggest reflection origin for both the components. However, such spectral variability cannot be explained by the light bending model alone and requires changes in the accretion disk/corona geometry possibly arising from changes in the accretion rate.

Category: Physics