SEARCH FOR VERY-HIGH-ENERGY GAMMA-RADIATION FROM THE RADIO BRIGHT REGION DR4 OF THE SNR G78.2+2.1

Authors
PROSCH C FEIGL E PLAGA R ARQUEROS F CORTINA J FERNANDEZ J FERNANDEZ P FONSECA V FUNK B GONZALEZ JC HAUSTEIN V HEINZELMANN G KARLE A KRAWCZYNSKI H KRENNRICH F KUHN M LINDNER A LORENZ E MAGNUSSEN N MARTINEZ S MATHEIS V MERCK M MEYER H MIRZOYAN R MOLLER H MORALEJO A MULLER N PADILLA L PRAHL J RHODE W SAMORSKI M SANCHEZ JA SANDER H SCHMELE D STAMM W WAHL H WESTERHOFF S WIEBELSOOTH B WILLMER M
Citation
C. Prosch et al., SEARCH FOR VERY-HIGH-ENERGY GAMMA-RADIATION FROM THE RADIO BRIGHT REGION DR4 OF THE SNR G78.2+2.1, Astronomy and astrophysics, 314(1), 1996, pp. 275-280
Citations number
15
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Astronomy and astrophysics → ACNP
ISSN journal
00046361
Volume
314
Issue
1
Year of publication
1996
Pages
275 - 280
Database
ISI
SICI code
0004-6361(1996)314:1<275:SFVGFT>2.0.ZU;2-Y
Abstract
Data from the HEGRA air shower array are used to set an upper limit on the emission of gamma-radiation above 25 (18) TeV from the direction of the radio bright region DR4 within the SNR G78.2 + 2.1 of 2.5 (7.1) . 10(-13) cm(-2) sec(-1). The shock front of SNR G78.2 + 2.1 probably recently overtook the molecular cloud Gong 8 which then acts as a targ et for the cosmic rays produced within the SNR, thus leading to the ex pectation of enhanced gamma-radiation. Using a model of Drury, Aharoni an and Volk which assumes that SNRs are the sources of galactic cosmic rays via first order Fermi acceleration, we calculated a theoretical prediction for the gamma-ray flux from the DR4 region and compared it with our experimental flux limit. Our 'best estimate' value for the pr edicted flux lies a factor of about 18 above the upper limit for gamma -ray energies above 25 TeV. Possible reasons for this discrepancy are discussed.