NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-06-20 T05:37:23 PDT
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For refcode 1993ApJ...416L..53L:
Retrieve 22 NED objects in this reference.
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NED Abstract

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1993ApJ...416L..53L EGRET LIMITS ON HIGH-ENERGY GAMMA-RAY EMISSION FROM X-RAY- AND LOW-ENERGY GAMMA-RAY-SELECTED SEYFERT GALAXIES Y. C. LIN, D. L. BERTSCH, B. L. DINGUS, C. E. FICHTEL, R. C. HARTMAN, S. D. HUNTER, G. KANBACH, D. A. KNIFFEN, J. R. MATTOX, H. A. MAYER-HASSELWANDER, P. F. MICHELSON, C. VON MONTIGNY, P. L. NOLAN, E. SCHNEID, P. SREEKUMAR, AND D. J. THOMPSON Received 1993 February 24; accepted 1993 August 4 ABSTRACT A sample of 22 Seyfert galaxies, 11 type 1 and two type 2 galaxies selected according to their X-ray fluxes in the AGN survey catalogs of EXOSAT and Ginga, two additional type 1 galaxies for which detections in low-energy gamma rays have been reported in the past, plus six more type 1 galaxies and one unclassified Seyfert that have been studied by the OSSE collaboration, have been examined for high-energy gamma ray emission in observations by the EGRET telescope on the Compton Observatory. No high-energy gamma-ray emission has been detected from any of them. The 2 {sigma} upper limits of the gamma-ray fluxes above 100 MeV for these 22 Seyfert galaxies are given here. The significance of these negative results is discussed. Implications of the EGRET result for NGC 4151 are discussed in more detail. Subject headings: galaxies: Seyfert - gamma rays: observations
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