NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-23 T08:29:20 PDT
Help | Comment | NED Home

For refcode 1989ApJ...339..674M:
Retrieve 118 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
1989ApJ...339..674M ON THE RATIO OF THE INFRARED-TO-ULTRAVIOLET CONTINUUM TO THE X-RAYS IN QUASARS AND ACTIVE GALAXIES R. F. MUSHOTZKY NASA/Goddard Space Flight Center AND A. WANDEL Center for Space Science and Astrophysics, Stanford University ABSTRACT Analyzing a sample of 122 quasars and Seyfert galaxies, we find that the near-infrared, 7500 A rest frame luminosity is more linearly related to the X-ray luminosity (L_x_ is proportional to L^0.85 +/- 0.05^_7500_) than is the optical 4200 A) luminosity. A similar result is achieved when considering only partial samples, such as radio-bright and radio-quiet objects separately, and excluding low-luminosity objects (likely to be contaminated by starlight) or X-ray upper limits. We also find that the mean spectral slope between 7500 and 4200 A ({alpha}_rb_) in the rest frame monotonically flattens with luminosity, over more than three orders of magnitude; for a larger sample of 193 objects we find {alpha}_rb_ is proportional to L^0.50 +/- 0.05^. This phenomenologically explains the observation that the X-ray luminosity has a flatter dependence on the optical than on the infrared luminosity, found in this work and by other authors. Our results support models which attribute the IR and X-ray continua to linked nonthermal processes such as synchrotron self-Compton, while the blue-UV bump comes from a different source, such as an accretion disk. Subject headings: galaxies: nuclei - quasars - radiation mechanisms - X-rays: sources
Retrieve 118 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home