SIMBAD references

2017ApJ...839..101Z - Astrophys. J., 839, 101-101 (2017/April-3)

X-ray insights into the nature of quasars with redshifted broad absorption lines.

ZHANG N.-X., BRANDT W.N., AHMED N.S., HALL P.B., LUO B., ANDERSON S.F., AK N.F., PETITJEAN P., SCHNEIDER D.P., SHEN Y. and SRIANAND R.

Abstract (from CDS):

We present Chandra observations of seven broad absorption line (BAL) quasars at z=0.863–2.516 with redshifted BAL troughs (RSBALs). Five of our seven targets were detected by Chandra in 4-13 ks exposures with ACIS-S. The αox values, Δαox values, and spectral energy distributions of our targets demonstrate they are all X-ray weak relative to expectations for non-BAL quasars, and the degree of X-ray weakness is consistent with that of appropriately matched BAL quasars generally. Furthermore, our five detected targets show evidence for hard X-ray spectral shapes with a stacked effective power-law photon index of Γeff=0.5–0.4+0.5. These findings support the presence of heavy X-ray absorption (NH~2×1023 cm–2) in RSBAL quasars, likely by the shielding gas found to be common in BAL quasars more generally. We use these X-ray measurements to assess models for the nature of RSBAL quasars, finding that a rotationally dominated outflow model is favored while an infall model also remains plausible with some stipulations. The X-ray data disfavor a binary quasar model for RSBAL quasars in general.

Abstract Copyright: © 2017. The American Astronomical Society. All rights reserved.

Journal keyword(s): accretion, accretion disks - galaxies: nuclei - quasars: absorption lines - quasars: general - X-rays: galaxies - X-rays: galaxies

Simbad objects: 7

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