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arXiv · astro-ph/0305285

A Puzzling X-Ray Source Found in the chandra Deep Field South

J. Wang·T. Yaqoob·G. Szokoly·R. Gilli·L. Kewley·V. Mainieri·M. Nonino·P. Rosati·P. Tozzi·W. Zheng·A. Zirm·C. Norman
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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.

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J. Wang, T. Yaqoob, G. Szokoly, R. Gilli, L. Kewley, V. Mainieri, M. Nonino, P. Rosati, P. Tozzi, W. Zheng, A. Zirm, C. Norman. 2003-05-15. A Puzzling X-Ray Source Found in the chandra Deep Field South. https://doi.org/10.1086/376821

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