The broad-band X-ray spectrum of the blazar PKS B1830-211 by Chandra and INTEGRAL
1
IASF - Sezione di Roma, INAF, via del Fosso del Cavaliere 100, 00113 Roma, Italy e-mail: derosa@rm.iasf.cnr.it
2
Dipartimento di Fisica, Università La Sapienza, Piazzale A. Moro 2, 00185 Roma, Italy
3
Geneva Observatory, INTEGRAL Science Data Centre, Chemin d'Ecogia 16, 1291 Versoix, Switzerland
4
IASF - Sezione di Bologna, INAF, via P. Gobetti 101, 40129 Bologna, Italy
5
School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
Received:
17
January
2005
Accepted:
5
April
2005
In this paper we present a broad-band study of the X-ray emission of the
blazar PKS 1830-211 based on Chandra and INTEGRAL observations.
Notwithstanding the high redshift (
), it is a bright X-ray
source (F(2–10 keV) 
erg cm-2 s-1), due to
gravitational lensing by an intervening galaxy at 
.
Previous X-ray observations attribute the observed absorption at
keV to the lensing galaxy. Our analysis, although not in
contrast with this hypothesis, suggests also the possibility of
an intrinsic (ionized) absorption, taking place at the front side of
the jet.
This scenario is also supported by some evidence, in the same data, of
a feature observed at 2.15 keV which can be interpreted as
a blueshifted iron line (
).
The SED of PKS 1830-211 can be well modelled by combining a Synchrotron
Self-Compton component and an external source of photons
to be scattered up to γ-ray energies by relativistic
electrons moving outward in the jet.
The main source of low energy photons is a dust torus at the
temperature of 103 K as expected in MeV blazars.
Key words: radiation mechanisms: non-thermal / galaxies: active / X-rays: galaxies: individual: PKS B1830-211
© ESO, 2005