Volume 514, May 2010
|Number of page(s)||6|
|Published online||21 May 2010|
INTEGRAL and Swift/XRT observations of the source PKS 0208-512
Key Laboratory for Particle Astrophysics, Institute of High
Energy Physics, Beijing 100049, PR China e-mail: firstname.lastname@example.org
2 Max-Planck-Institut für Extraterrestrische Physik, PO Box 1603, 85740 Garching, Germany
3 ICREA & Institut de Ciències de l'Espai (IEEC-CSIC), Campus UAB, Facultat de Ciències, Torre C5-parell, 2a planta, 08193 Barcelona, Spain
4 Theoretical Physics Center for Science Facilities (TPCSF), CAS, PR China
Accepted: 9 February 2010
Aims. The active galaxy PKS 0208-512, detected at lower energies by COMPTEL, has been claimed to be a MeV blazar from EGRET. We report on the most recent INTEGRAL observations of the blazar PKS 0208-512, which are supplemented by Swift ToO observations.
Methods. The high energy X-ray and γ-ray emission of PKS 0208-512 during August–December 2008 has been studied using 682 ks of INTEGRAL guest observer time and ~56 ks of Swift/XRT observations. These data were collected during the decay of a γ-ray flare observed by Fermi/LAT.
Results. At X-ray energies (0.2–10 keV) PKS 0208-512 is significantly detected by Swift/XRT, showing a power-law spectrum with a photon index of ~1.64. Its X-ray luminosity varied by roughly 30% during one month. At hard X-/soft γ-ray energies PKS 0208-512 shows a marginally significant (~3.2σ) emission in the 0.5–1 MeV band when combining all INTEGRAL/SPI data. Non-detections at energies below and above this band by INTEGRAL/SPI may indicate intrinsic excess emission. If this possible excess is produced by the blazar, one possible explanation could be that its jet consists of an abundant electron-positron plasma, which may lead to the emission of an annihilation radiation feature. Assuming this scenario, we estimate physical parameters of the jet of PKS 0208-512.
Key words: X-rays: individuals: PKS 0208-512
© ESO, 2010
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.