Published October 7, 2001 | Version v1
Journal article

The nature of the EGRET source 3EG J1621+8203

  • 1. Department of Physics and Astronomy, Barnard College, Columbia University, New York, New York 10027 (United States)
  • 2. Columbia Astrophysics Lab, Columbia University, New York, New York 10027 (United States)

Description

We present broad-band observations of 3EG J1621+8203 in an effort to understand the nature of this source. We have examined X-ray images of the field from the ROSAT PSPC, ROSAT HRI, and ASCA GIS to search for a possible counterpart to the EGRET source. We find several faint X-ray point sources in the gamma-ray error circle. Preliminary analysis indicates that most of the point sources correspond to stars or to faint radio sources. Of the nearly 40% identified sources in the 3EG Catalog, the vast majority are blazars, but there is no blazer candidate in the error circle of 3EG J1621+8203. Of the notable objects in the EGRET error circle, one is the bright FR I radio galaxy NGC 6251 at a redshift of 0.0249. If NGC 6251 is the counterpart to the EGRET source 3EG J1621+8203, then it would be the second radio galaxy to be detected by EGRET. The first was Centaurus A. Cen A provided the first clear evidence of the detection above 100 MeV of an AGN with a large-inclination jet. If the identification with NGC 6251 is correct, the apparent gamma-ray luminosity of 3EG J1621+8203 is lower than that of other EGRET blazars; just as in the case of Cen A

Additional details

Identifiers

Publishing Information

Journal Title
AIP Conference Proceedings
Journal Volume
587
Journal Issue
1
Journal Page Range
p. 304-308
ISSN
0094-243X
CODEN
APCPCS

Conference

Title
Gamma-ray astrophysics 2001
Acronym
6. Compton symposium
Dates
4-6 Apr 2001
Place
Baltimore, MD (United States)

INIS

Optional Information

Notes
(c) 2001 American Institute of Physics.