Upper limits on TeV gamma-ray emission from active galactic nuclei

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Astrophysical Journal

DOI:https://doi.org/10.1086/176331· OSTI ID:281998

Kerrick, A D ^[1]; Akerlof, C W ^[2]; Biller, S ^[3]; Buckley, J ^[4]; Carter-Lewis, D A ^[1]; Cawley, M F ^[5]; Chantell, M ^[4]; Connaughton, V ^[4]; Fegan, D J; Fennell, S ^[6]; Gaidos, J ^[7]; Hillas, A M ^[3]; Kwok, P W; Lamb, R C ^[1]; Lappin, T ^[4]; Lessard, R; McEnery, J ^[6]; Meyer, D I ^[2]; Mohanty, G ^[1]; Quinn, J

---

1. Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011-3160 (United States)
2. Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48109-1120 (United States)
3. Department of Physics, University of Leeds, Leeds, LS2 9JT, Yorkshire, England (United Kingdom)
4. Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, P.O. Box 97, Amado, Arizona 85645-0097 (United States)
5. Physics Department, St. Patricks College, Maynooth, County Kildare (Ireland)
6. Physics Department, University College, Dublin (Ireland)
7. Department of Physics, Purdue University, West Lafayette, Indiana 47907 (United States)

The results of a search for TeV gamma-ray emission from 35 active galactic nuclei (AGNs) using the Whipple Observatory High Resolution Atmospheric Cerenkov Camera are reported. Fifteen of these objects have been detected at GeV energies by the EGRET experiment on the {ital Compton} {ital Gamma} {ital Ray} {ital Observatory}. None of the 35 objects gave a signal at the 3 {sigma} level; Mrk 421 remains the only AGN detected at TeV energies. The absence of a TeV signal may imply a change in the primary source spectrum and/or the effect of absorption by pair production on intergalactic infrared photons. {copyright} {ital 1995 The American Astronomical Society.}

• OSTI ID: 281998
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 452; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ACTIVE GALAXIES
ACTIVE GALAXY NUCLEI
COSMIC GAMMA SOURCES
ENERGY SPECTRA
GALAXY NUCLEI
GAMMA RADIATION
INFRARED RADIATION
MARKARIAN GALAXIES
QUASARS
SEYFERT GALAXIES
TEV RANGE