A Puzzling X-Ray Source Found in the chandra Deep Field South
Abstract
In this letter we report the detection of an extremely strong X-ray emission line in the 940ks chandra ACIS-I spectrum of CXO CDFS J033225.3-274219. The source was identified as a Type1 AGN at redshift of z = 1.617, with 2.0 -- 10.0 keV rest frame X-ray luminosity of ~ 10^44 ergs s^-1. The emission line was detected at 6.2^{+0.2}_{-0.1} keV, with an equivalent width (EW) of 4.4^{+3.2}_{-1.4} keV, both quantities referring to the observed frame. In the rest frame, the line is at 16.2^{+0.4}_{-0.3} keV with an EW of 11.5^{+8.3}_{-3.7} keV. An X-ray emission line at similar energy (~ 17 keV, rest frame) in QSO PKS 2149-306 was discovered before using ASCA data. We reject the possibility that the line is due to a statistical or instrumental artifact. The line is most likely due to blueshifted Fe-K emission from an relativistic outflow, probably an inner X-ray jet, with velocities of the order of ~ 0.6-0.7c. Other possible explanations are also discussed.
Cite
@article{arxiv.astro-ph/0305285,
title = {A Puzzling X-Ray Source Found in the chandra Deep Field South},
author = {J. Wang and T. Yaqoob and G. Szokoly and R. Gilli and L. Kewley and V. Mainieri and M. Nonino and P. Rosati and P. Tozzi and W. Zheng and A. Zirm and C. Norman},
journal= {arXiv preprint arXiv:astro-ph/0305285},
year = {2015}
}