BROADBAND JET EMISSION IN YOUNG AND POWERFUL RADIO SOURCES: THE CASE OF THE COMPACT STEEP SPECTRUM QUASAR 3C 186
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
- SISSA, Via Bonomea 265, I-34136 Trieste (Italy)
We present the X-ray analysis of a deep ({approx}200 ks) Chandra observation of the compact steep spectrum radio-loud quasar 3C 186 (z = 1.06) and investigate the contribution of the unresolved radio jet to the total X-ray emission. The spectral analysis is not conclusive on the origin of the bulk of the X-ray emission. In order to examine the jet contribution to the X-ray flux, we model the quasar spectral energy distribution, adopting several scenarios for the jet emission. For the values of the main physical parameters favored by the observables, a dominant role of the jet emission in the X-ray band is ruled out when a single-zone (leptonic) scenario is adopted, even including the contribution of the external photon fields as seed photons for inverse Compton emission. We then consider a structured jet, with the blazar component that-although not directly visible in the X-ray band-provides an intense field of seed synchrotron photons Compton-scattered by electrons in a mildly relativistic knot. In this case, the whole X-ray emission can be accounted for if we assume a blazar luminosity within the range observed from flat spectrum radio quasars. The X-ray radiative efficiency of such a (structured) jet is intimately related to the presence of a complex velocity structure. The jet emission can provide a significant contribution in X-rays if it decelerates within the host galaxy on kiloparsec scales. We discuss the implications of this model in terms of jet dynamics and interaction with the ambient medium.
- OSTI ID:
- 22020427
- Journal Information:
- Astrophysical Journal, Vol. 749, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
FLARING BEHAVIOR OF THE QUASAR 3C 454.3 ACROSS THE ELECTROMAGNETIC SPECTRUM
MULTIWAVELENGTH OBSERVATIONS OF THE GAMMA-RAY BLAZAR PKS 0528+134 IN QUIESCENCE