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A New Look at Optical and X-ray Emission in SDSS/XMM-Newton Quasars

Published online by Cambridge University Press:  21 October 2010

Monica C. B. Young
Monica C. B. Young*
Affiliation:
Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA email: myoung@head.cfa.harvard.edu Department of Astronomy, Boston University, 725 Commonwealth Ave. Boston, MA 02215, USA
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Abstract

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We develop a new approach to the well-studied anti-correlation between the optical-to-X-ray spectral index, αox, and the monochromatic optical luminosity, lopt. By cross-correlating the SDSS DR5 quasar catalog with the XMM-Newton archive, we create a sample of 327 quasars with both optical and X-ray spectra, allowing αox to be defined at arbitrary frequencies, rather than the standard 2500 Å and 2 keV. We find that while the choice of optical wavelength does not strongly influence the αox−lopt relation, the slope of the relation flattens significantly with X-ray energy. This result suggests a change in the efficiency of X-ray photon production, where the efficiency of low energy X-ray production depends more strongly on the seed (optical/UV) photon supply. We discuss implications for line-driven wind models.

Keywords

quasars: generalgalaxies: activeaccretionaccretion disks
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 5 , Highlights H15: Highlights of Astronomy , November 2009 , pp. 263 - 265
Copyright
Copyright © International Astronomical Union 2010

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