English

PG 1254+047: An Intrinsically X-ray Weak, Heavily Absorbed BALQSO?

Astrophysics 2007-05-23 v2

Abstract

We present \textit{Chandra} observations of the radio-quiet Broad Absorption Line (BAL) QSO PG 1254+047. We find that it is a weak X-ray source, with a total of 44±744\pm 7 photons measured in 36 ksec across the observed energy range 0.76.00.7 - 6.0 keV. Its X-ray weakness is consistent with the known correlation between αox\alpha_{ox} and the strength of the UV absorption lines. The spectral energy distribution suggests that PG 1254+047 is intrinsically X-ray weak, in addition to being heavily X-ray absorbed. The X-ray absorption column density is NH>1023N_{H} > 10^{23} cm2^{-2} for neutral gas, while the intrinsic (unabsorbed) emission spectrum has αox>2\alpha_{ox} > 2. The data are fit best by including an ionized (rather than neutral) absorber, with column density NH2×1023N_{H} \gtrsim 2\times 10^{23} cm2^{-2}. The degree of ionization is consistent with the UV BALs, as is the total column density if the strongest UV lines are saturated. If the X-ray absorber forms in a wind that is radiatively accelerated to the BAL velocities, then the wind must be launched from a radius of about 101610^{16} cm with a mass loss rate of 1\sim 1 M_\odot yr1^{-1}.

Keywords

Cite

@article{arxiv.astro-ph/0108383,
  title  = {PG 1254+047: An Intrinsically X-ray Weak, Heavily Absorbed BALQSO?},
  author = {Bassem M. Sabra and Fred Hamann},
  journal= {arXiv preprint arXiv:astro-ph/0108383},
  year   = {2007}
}

Comments

Accepted for publication in the Astrophysical Journal