COMPTEL MeV Observations of the TeV Sources Markarian 421 and Markarian 501
Abstract
The COMPTEL experiment aboard the COMPTON Gamma-Ray Observatory (CGRO) has observed the prominent TeV-blazars Mkn 421 and Mkn 501 many times between the start of its mission in April '91 and December '98. This paper reports first COMPTEL results from mainly time-averaged (CGRO Cycles) data. No evidence for both sources is found up to the end Cycle VI. However, the sum of all 10-30 MeV Cycle VII data shows a weak (3.2 sigma detection) MeV-source being positionally consistent with Mkn 421. During Cycle VII Mkn 421 was rather active at TeV-energies. Due to the lack of other known Gamma-ray sources in this sky region, we consider Mkn 421 as the most likely counterpart for this Gamma-ray emission. However, its connection cannot be proven by COMPTEL.
Cite
@article{arxiv.astro-ph/9912042,
title = {COMPTEL MeV Observations of the TeV Sources Markarian 421 and Markarian 501},
author = {W. Collmar and K. Bennett and H. Bloemen and W. Hermsen and J. Ryan and V. Schoenfelder and H. Steinle and O. R. Williams},
journal= {arXiv preprint arXiv:astro-ph/9912042},
year = {2007}
}
Comments
4 pages including 4 figures, latex2e, appeared in: 'Proc. of 26th ICRC', Salt Lake City, USA