NGC 4051: Black hole mass and photon index-mass accretion rate correlation
Abstract
We present a discovery of the correlation between the X-ray spectral (photon) index and mass accretion rate observed in AGN NGC 4051. We analyzed spectral transition episodes observed in NGC 4051 using XMM/Newton, Suzaku and RXTE. We applied a scaling technique for a black hole (BH) mass evaluation which uses a correlation between the photon index and normalization of the seed (disk) component, which is proportional to a mass accretion rate. We developed an analytical model that shows the spectral (photon) index of the BH emergent spectrum undergoes an evolution from lower to higher values depending on a mass accretion rate in the accretion disk. We considered Cygnus X-1 and GRO~J1550-564 as reference sources for which distances, inclination angles and the BH masses are evaluated by dynamical measurements. Application of the scaling technique for the photon index-mass accretion rate correlation provides an estimate of the black hole mass in NGC 4051 to be more than 6x10^5 solar masses.
Cite
@article{arxiv.1802.07337,
title = {NGC 4051: Black hole mass and photon index-mass accretion rate correlation},
author = {Elena Seifina and Alexandre Chekhtman and Lev Titarchuk},
journal= {arXiv preprint arXiv:1802.07337},
year = {2018}
}
Comments
11 pages, 6 Figures and 8 Tables. arXiv admin note: text overlap with arXiv:0902.2852