Discovery of fe Kα X-Ray reverberation around the black holes in MCG-5-23-16 and NGC 7314


Type
Article
Change log
Authors
Zoghbi, A 
Reynolds, Christopher  ORCID logo  https://orcid.org/0000-0002-1510-4860
Cackett, EM 
Miniutti, G 
Kara, E 
Abstract

Several X-ray observations have recently revealed the presence of reverberation time delays between spectral components in AGN. Most of the observed lags are between the power-law Comptonization component, seen directly, and the soft excess produced by reflection in the vicinity of the black hole. NGC 4151 was the first object to show these lags in the iron K band. Here, we report the discovery of reverberation lags in the Fe K band in two other sources: MCG-5-23-16 and NGC 7314. In both objects, the 6-7 keV band, where the Fe K line peaks, lags the bands at lower and higher energies with a time delay of ~ 1 kilo-seconds. These lags are unlikely to be due to the narrow Fe K line. They are fully consistent with reverberation of the relativistically-broadened iron K line. The measured lags, their time-scale and spectral modeling, indicate that most of the radiation is emitted at ~ 5 and 24 gravitational radii for MCG-5-23-16 and NGC 7314 respectively.

Description
Keywords
accretion, accretion disks, black hole physics, galaxies: active, galaxies: groups: individual (MCG-5-23-16, NGC 7314), galaxies: nuclei, gravitation, X-rays: galaxies
Journal Title
Astrophysical Journal
Conference Name
Journal ISSN
0004-637X
1538-4357
Volume Title
767
Publisher
American Astronomical Society
Sponsorship
Science and Technology Facilities Council (ST/J001538/1)
Science and Technology Facilities Council (ST/K000985/1)