γ-Ray emission from Arp 220: indications of an active galactic nucleus
Artikel i vetenskaplig tidskrift, 2017

Extragalactic cosmic ray populations are important diagnostic tools for tracking the distribution of energy in nuclei and for distinguishing between activity powered by star formation versus active galactic nuclei (AGNs). Here, we compare different diagnostics of the cosmic ray populations of the nuclei of Arp 220 based on radio synchrotron observations and the recent gamma-ray detection. We find the gamma-ray and radio emission to be incompatible; a joint solution requires at minimum a factor of 4-8 times more energy coming from supernovae and a factor of 40-70 more mass in molecular gas than that is observed. We conclude that this excess of the gamma-ray flux in comparison to all other diagnostics of star-forming activity indicates that there is an AGN present that is providing the extra cosmic rays, likely in the western nucleus.

gamma rays: galaxies

Supermassive Black-Holes

Continuum

galaxies: star-burst

galaxies: active

Galaxies

Array

cosmic rays

Coevolution

galaxies: individual: (Arp 220)

Resolution

Fermi-Lat

Arp-220

Författare

T. M. Yoast-Hull

Canadian Institute for Theoretical Astrophysics

J. S. Gallagher III

University of Wisconsin Madison

Susanne Aalto

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

Eskil Varenius

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 469 1 L89-L93

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1093/mnrasl/slx054

Mer information

Senast uppdaterat

2020-04-29