Astronomy and Astrophysics – Astronomy
Scientific paper
Jun 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994apjs...92..623s&link_type=abstract
The Astrophysical Journal Supplement Series, vol. 92, no. 2, p. 623-625
Astronomy and Astrophysics
Astronomy
4
Active Galactic Nuclei, Bl Lacertae Objects, Gamma Ray Astronomy, Gamma Ray Spectra, Quasars, Spectral Emission, Gamma Ray Observatory, Surveys
Scientific paper
The Compton Gamma-Ray Observatory (CGRO) Instruments, in particular, EGRET, have recently discovered new, gamma-ray bright active galactic nuclei (AGNs)(fluxes approximately 0.5-3 times as bright as 3C 273). Yet current sample sizes are modest (for example, EGRET as of 1993 January has detected 17 quasars and five BL Lac objects), and the sources probe only a small range in flux. Only by using a large, unbiased sample of AGNs can we answer key questions about source evolution, contributions to the gamma-ray background, and the different gamma-ray properties of quasars and BL Lac objects. Therefore, we need gamma-ray data on a much larger number of AGNs. We are currently pursuing two approaches toward remedying this situation: first, new (phase 2) OSSE, COMPTEL, and EGRET observations of X-ray selected AGNs predicted to be gamma-ray bright on simple assumptions; even an upper limit can set constraints on continuum models (e.g., pair production, synchrotron self-Compton); second, searches for radio-selected AGNs in wide-field EGRET data obtained during the pointings. For these AGN, we expect a large number of faint sources (i.e., mainly low signal-to-noise ratio detections and upper limits), a continuous progression down to the limiting EGRET sensitivity. Although special techniques must be employed to deal carefully with low-significance sources, the end product will be a much larger sample than currently available on which to base deductions about the gamma-ray properties of AGNs. Here we report the first results of this program. We find an upper limit for 3C 382 and demonstrate, using the 3C 382 field, how serendipitous blazars can systematically searched for in existing EGRET public (Phase 1) data. Preliminary results indicate that synchrotron self-Compton processes dominate.
Elvis Martin
Schachter Jonathan
No associations
LandOfFree
Gamma-ray bright quasars and BL Lacertae objects: EGRET data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Gamma-ray bright quasars and BL Lacertae objects: EGRET data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gamma-ray bright quasars and BL Lacertae objects: EGRET data will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1863149