Fermi Gamma-Ray Imaging of a Radio Galaxy
Abstract
The Fermi Gamma-ray Space Telescope has detected the γ-ray glow emanating from the giant radio lobes of the radio galaxy Centaurus A. The resolved γ-ray image shows the lobes clearly separated from the central active source. In contrast to all other active galaxies detected so far in high-energy γ-rays, the lobe flux constitutes a considerable portion (greater than one-half) of the total source emission. The γ-ray emission from the lobes is interpreted as inverse Compton-scattered relic radiation from the cosmic microwave background, with additional contribution at higher energies from the infrared-to-optical extragalactic background light. These measurements provide γ-ray constraints on the magnetic field and particle energy content in radio galaxy lobes, as well as a promising method to probe the cosmic relic photon fields.
- Publication:
-
Science
- Pub Date:
- May 2010
- DOI:
- 10.1126/science.1184656
- arXiv:
- arXiv:1006.3986
- Bibcode:
- 2010Sci...328..725A
- Keywords:
-
- ASTRONOMY;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Cosmology and Extragalactic Astrophysics
- E-Print:
- 27 pages, includes Supplementary Online Material