A historic jet-emission minimum reveals hidden spectral features in 3C 273
/ Authors
M. Turler, M. Chernyakova, T. Courvoisier, C. Foellmi, M. Aller, H. Aller, A. Kraus, T. Krichbaum, A. Lahteenmaki, A. Marscher
and 7 more authors
I. McHardy, P. O’Brien, K. Page, L. Popescu, E. Robson, M. Tornikoski, H. Ungerechts
/ Abstract
Aims. The aim of this work is to identify and study spectral features in the quasar 3C 273 usually blended by its strong jet emission. Methods. A historic minimum in the sub-millimetre emission of 3C 273 triggered coordinated multi-wavelength observations in June 2004. X-ray observations from the INTEGRAL, XMM-Newton and RXTE satellites are complemented by ground-based optical, infrared, millimetre and radio observations. The overall spectrum is used to model the infrared and X-ray spectral components. Results. Three thermal dust emission components are identified in the infrared. The dust emission on scales from 1 pc to several kpc is comparable to that of other quasars, as expected by AGN unification schemes. The observed weakness of the X-ray emission supports the hypothesis of a synchrotron self-Compton origin for the jet component. There is a clear soft-excess and we find evidence for a very broad iron line which could be emitted in a disk around a Kerr black hole. Other signatures of a Seyfert-like X-ray component are not detected.
Journal: Astronomy and Astrophysics