2009/02/11 by V. Bianchin, L. Foschini, G. Ghisellini +8
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Radio Astronomy Observations and Technology #astro-ph.CO #astro-ph.HE
paper · pdf · doi:10.1051/0004-6361/200811128
7 pages, 2 figures. A&A accepted for publication
arxiv created 2009/02/11 · openalex publication_date 2009/02/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
<i>Aims. <i/> We study the blazar nature of the high-redshift Flat-Spectrum Radio Quasar PKS 2149-306 () by investigating its long-term behavior.<i>Methods. <i/>We analyzed all publicly available optical-to-X-ray observations performed by <i>XMM-Newton<i/>, <i>Swift<i/>, and <i>INTEGRAL<i/>.<i>Results. <i/>PKS 2149-306 is one of four blazars at that have been observed in the hard-X-ray regime with both the BAT and ISGRI instruments. Observations acquired almost 1 year apart in the keV energy band in the object rest frame, exhibit no noticeable change in spectral slope associated with a flux variation of more than a factor of two. <i>Swift<i/> data appear to show a roll-off below ~1 keV, which becomes increasingly evident during a ~3-day time-frame, that can be explained as the natural spectral break caused by the Inverse Compton onset. The broad-band spectra allow us to identify two different states. The SED modeling suggests that they can be interpreted by only a change in the bulk Lorentz factor of the jet.