High-Energy Properties of PKS 1830-211
Abstract
We report an analysis of X-ray and γ-ray observations of PKS 1830-211, based on long-term campaigns carried out by INTEGRAL and COMPTEL. The INTEGRAL data currently available provide a 33 σ significance detection in the 20-100 keV band, while the COMPTEL 6 yr data provide a 5.2 σ significance detection in the 1-3 MeV energy band. In hard X-rays, INTEGRAL and supplementary Swift observations show flux variability on timescales of months. In γ-rays, the source shows persistent emission over years. The hard X-ray spectrum is well represented by a power-law model, with Γ ~ 1.3 in the 20-250 keV band. This photon index is consistent with a previous report of Γ ~ 1.3 obtained at E > 3.5 keV from XMM-Newton data fitted with a broken power law model. The joint XMM-Newton and INTEGRAL spectrum presented here is thus fitted with a broken power law model; the parameters are refined as compared with the previous fit. The results show that the photon index changes from ~1.0 to ~1.3 at a break energy of ~4 keV. At MeV energies, the spectrum softens to Γ ~ 2.2. These results, together with an EGRET measurement at E >= 100 MeV, constitute a broadband spectrum containing the peak of the power output at MeV energies, similar to most high-luminosity γ-ray blazars. The measured spectral characteristics are discussed in the framework of gravitational lensing effects.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2008
- DOI:
- 10.1086/589498
- arXiv:
- arXiv:0803.1900
- Bibcode:
- 2008ApJ...683..400Z
- Keywords:
-
- X-rays: individual: PKS 1830–211;
- Astrophysics
- E-Print:
- accepted for ApJ