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The z=5.8 Quasar SDSSp J1044-0125: A Peek at Quasar Evolution?

Smita Mathur
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Abstract

The newly discovered z=5.8 quasar SDSSp J104433.04-012502.2 was recently detected in X-rays and found to be extremely X-ray weak. Here we present the hardness ratio analysis of the XMM-Newton observation. We consider various models to explain the detection in the soft X-ray band and non-detection in the hard band, together with its X-ray weakness. We show that the source may have a steep power-law slope, with an absorber partially covering the continuum. This may be X-ray evidence to support the argument of Mathur (2000) that narrow line Seyfert 1 galaxies, which show steep power-law slopes, might be the low redshift, low luminosity analogues of the high redshift quasars. Heavily shrouded and steep X-ray spectrum quasars may indeed represent the early stages of quasar evolution (Mathur 2000, Fabian 1999) and SDSSp J104433.04-012502.2 is possibly giving us a first glimpse of the physical evolution of quasar properties.

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Smita Mathur. 2001-07-09. The z=5.8 Quasar SDSSp J1044-0125: A Peek at Quasar Evolution?. https://doi.org/10.1086/323307

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