Possible Production of High-Energy Gamma Rays from Proton Acceleration in the Extragalactic Radio Source Markarian 501
- 30 January 1998
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 279 (5351) , 684-686
- https://doi.org/10.1126/science.279.5351.684
Abstract
The active galaxy Markarian 501 was discovered with air-Cerenkov telescopes at photon energies of 10 tera–electron volts. Such high energies may indicate that the gamma rays from Markarian 501 are due to the acceleration of protons rather than electrons. Furthermore, the observed absence of gamma ray attenuation due to electron-positron pair production in collisions with cosmic infrared photons implies a limit of 2 to 4 nanowatts per square meter per steradian for the energy flux of an extragalactic infrared radiation background at a wavelength of 25 micrometers. This limit provides important clues about the epoch of galaxy formation.Keywords
All Related Versions
This publication has 20 references indexed in Scilit:
- Multiwavelength Observations of a Flare from Markarian 501The Astrophysical Journal, 1997
- The acceleration time-scale for first-order Fermi acceleration in relativistic shock wavesMonthly Notices of the Royal Astronomical Society, 1996
- Synchrotron Models for X-Rays from the Supernova Remnant SN 1006The Astrophysical Journal, 1996
- Evidence for shock acceleration of high-energy electrons in the supernova remnant SN1006Nature, 1995
- Unified Schemes for Radio-Loud Active Galactic NucleiPublications of the Astronomical Society of the Pacific, 1995
- Instrumentation for very high energy gamma-ray astronomyExperimental Astronomy, 1995
- X-ray emission from the radio hotspots of Cygnus ANature, 1994
- Relativistic bulk motion in active galactic nucleiThe Astrophysical Journal, 1993
- Quasars, Blazars, and Gamma RaysScience, 1992
- Rate of energy gain and maximum energy in diffusive shock accelerationThe Astrophysical Journal, 1987