English

Broad-line Region Clouds orbiting an AGN sample

Astrophysics of Galaxies 2022-06-08 v1 High Energy Astrophysical Phenomena

Abstract

We present a spectral and temporal analysis of XMM-Newton data from a sample of six galaxies (NGC 3783, Mrk 279, Mrk 766, NGC 3227, NGC 7314, and NGC 3516). Using the hardness-ratio curves, we identify time-intervals in which clouds are eclipsing the central X-ray source in five of the six sources. We detect three occultations in NGC 3227 and one occultation in NGC 3783, NGC 7314, and NGC 3516, together with the well-known occultations in Mrk 766. We estimate the physical properties of the eclipsing clouds. The derived physical size of the X-ray sources (\sim(3-28)×\times1013^{13} cm) is less than that of the eclipsing clouds with column densities of \sim1022^{22}-1023^{23} cm2^{-2}, thus a single cloud may block the X-ray source, leading to notorious temporal variability of the X-ray flux. The eclipsing clouds in Mrk 766, NGC 3227, NGC 7314, and NGC 3516 with distances from the X-ray source of \sim(0.3-3.6)×\times104^4 RgR_g are moving at Keplerian velocities >>1122 km s1^{-1}, typical parameters of broad-line region clouds, while the eclipsing cloud in NGC 3783 is likely located in the dusty torus. We also find a good anti-correlation with a slope of -187±\pm62 between the known masses of the supermassive black hole in the center of the galaxies with the equivalent width (EW) of the 6.4 keV Fe line for the five Seyfert 1 galaxies of our sample, while the Seyfert 2 galaxy NGC 7314 shows an average EW value of 100±\pm11 eV inconsistent with the above anti-correlation.

Keywords

Cite

@article{arxiv.2205.10626,
  title  = {Broad-line Region Clouds orbiting an AGN sample},
  author = {J. Armijos-Abendaño and E. López and M. Llerena and C. H. A. Logan},
  journal= {arXiv preprint arXiv:2205.10626},
  year   = {2022}
}

Comments

13 pages, 15 figures, accepted for publication in MNRAS

R2 v1 2026-06-24T11:24:20.299Z