COMPTEL observations of the gamma-ray blazar PKS 1622-297

Autor:	O. R. Williams, Mark L. McConnell, H. Bloemen, W. Collmar, K. Bennett, Shu Zhang, Stefan Wagner, Olaf Reimer, W. Hermsen, V. Schönfelder
Rok vydání:	2002
Předmět:	Physics biology Astrophysics::High Energy Astrophysical Phenomena Astrophysics (astro-ph) Gamma ray FOS: Physical sciences Astronomy and Astrophysics Astrophysics biology.organism_classification law.invention Space and Planetary Science law Energy spectrum Egret Power output Blazar Flare
Zdroj:	Astronomy & Astrophysics. 386:843-853
ISSN:	1432-0746 0004-6361
DOI:	10.1051/0004-6361:20020267
Popis:	We report results of observations and analyses on the gamma-ray blazar PKS 1622-297, with emphasis on the COMPTEL data (0.75 - 30 MeV) collected between April 1991 and November 1997. PKS 1622-297 was detected as a source of gamma-rays by the EGRET experiment aboard CGRO in 1995 during a gamma-ray outburst at energies above 100 MeV lasting for five weeks. In this time period the blazar was significantly (~ 5.9 sigma) detected by COMPTEL at 10-30 MeV. At lower COMPTEL energies the detection is marginal, resulting in a hard MeV spectrum. The combined COMPTEL/EGRET energy spectrum shows a break at MeV energies. The broad-band spectrum (radio - gamma-rays) shows that the gamma-ray emission dominates the overall power output. On top of the 5-week gamma-ray outburst, EGRET detected a huge flare lasting for > 1 day. Enhanced MeV emission (10 - 30 MeV) is found near the time of this flare, suggesting a possible time delay with respect to the emission above 100 MeV. Outside the 5-week flaring period in 1995, we do not detect MeV emission from PKS 1622-297. 10 pages including 9 figures, accepted for publication in A&A
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::274d8ac94b704ceb26994ad35fcd4405 https://doi.org/10.1051/0004-6361:20020267 Zobrazit plný text záznamu