X-ray Properties of Intermediate-mass Black Holes in Active Galaxies

Simple item page
dc.creatorGreene, Jenny E.
dc.creatorHo, Luis C.
dc.date2006-08-02
dc.date.accessioned2026-07-07T10:39:42Z
dc.date.available2026-07-07T10:39:42Z
dc.descriptionWe present a pilot study of the X-ray properties of intermediate-mass (~10^5-10^6 M_sun) black holes in active galaxies using the Chandra X-ray telescope. Eight of the 10 active galaxies are detected with a significance of at least 3 sigma, with X-ray luminosities in the range L_(0.5-2 keV) ~ 10^41-10^43 ergs/s. The optical-to-X-ray flux ratios are consistent with expectations, given the known correlations between alpha_ox and ultraviolet luminosity, while a couple of objects appear to be anomalously X-ray weak. The range of 0.5--2 keV photon indices we measure, 1 < Gamma_s < 2.7, is entirely consistent with values found in samples of more luminous sources with more massive black holes. Black hole mass evidently is not a primary driver of soft X-ray spectral index. On the other hand, we do find evidence for a correlation between X-ray power-law slope and both X-ray luminosity and Eddington ratio, which may suggest that X-ray emission mechanisms weaken at high Eddington ratio. Such a weakening may explain the X-ray weakness of one of our most optically luminous objects.
dc.descriptionSubmitted to ApJ on 7 April 2006, but still awaiting referee's report; 8 pages, 4 figures, uses emulateapj5.sty
dc.identifierhttps://arxiv.org/abs/astro-ph/0608061
dc.identifierhttp://arxiv.org/abs/astro-ph/0608061
dc.identifierAstrophys.J.656:84-92,2007
dc.identifierdoi:10.1086/509064
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/181123
dc.subjectAstrophysics
dc.titleX-ray Properties of Intermediate-mass Black Holes in Active Galaxies
dc.typetext

Files

Collections

arXiv