1. A connection between star formation activity and cosmic rays in the starburst galaxy M82
- Author
-
V. A. Acciari, M. J. Lang, A. Cesarini, Pierre Colin, John L. Quinn, L. C. Reyes, K. G. Gibbs, R. Guenette, J. E. Ward, A. N. Otte, Frank Krennrich, A. McCann, S. P. Swordy, R. Dickherber, T. Aune, Karen Byrum, T. Weisgarber, S. Thibadeau, M. Theiling, G. H. Gillanders, S. Godambe, Philip Kaaret, M. Schroedter, D. S. Hanna, T. C. Arlen, A. Imran, S. M. Bradbury, Wystan Benbow, J. Millis, Reshmi Mukherjee, F. Pizlo, S. J. Fegan, M. Beilicke, John Kildea, D. Steele, N. Karlsson, M. McCutcheon, David A. Williams, P. Moriarty, Gernot Maier, A. Cannon, Stephanie Wissel, D. Pandel, S. P. Wakely, Daniel Gall, D. Boltuch, J. H. Buckley, N. Galante, R. A. Ong, S. LeBohec, P. Cogan, G. Finnegan, A. W. Smith, David Kieda, Vladimir Vassiliev, C. Duke, Wei Cui, E. Roache, Thomas Brian Humensky, Jamie Holder, Lucy Fortson, Matthew Wood, V. Bugaev, S. McArthur, L. Ciupik, Amy Furniss, Geza Gyuk, E. Aliu, A. Varlotta, B. Zitzer, J. S. Perkins, K. Ragan, A. Konopelko, Martin Pohl, G. H. Sembroski, Henric Krawczynski, T. Nagai, R. G. Wagner, C. M. Hui, D. Horan, M. Kertzman, J. Grube, J. P. Finley, T. C. Weekes, P. T. Reynolds, S. Vincent, Y. C. Chow, O. Celik, Manuel A. Bautista, Amanda Weinstein, P. Fortin, and H. J. Rose
- Subjects
Physics ,High rate ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Multidisciplinary ,010308 nuclear & particles physics ,Star formation ,Protogalaxy ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy ,Cosmic ray ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Radiation ,01 natural sciences ,Galaxy ,Supernova ,Stars ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Although Galactic cosmic rays (protons and nuclei) are widely believed to be dominantly accelerated by the winds and supernovae of massive stars, definitive evidence of this origin remains elusive nearly a century after their discovery [1]. The active regions of starburst galaxies have exceptionally high rates of star formation, and their large size, more than 50 times the diameter of similar Galactic regions, uniquely enables reliable calorimetric measurements of their potentially high cosmic-ray density [2]. The cosmic rays produced in the formation, life, and death of their massive stars are expected to eventually produce diffuse gamma-ray emission via their interactions with interstellar gas and radiation. M 82, the prototype small starburst galaxy, is predicted to be the brightest starburst galaxy in gamma rays [3, 4]. Here we report the detection of >700 GeV gamma rays from M 82. From these data we determine a cosmic-ray density of 250 eV cm-3 in the starburst core of M 82, or about 500 times the average Galactic density. This result strongly supports that cosmic-ray acceleration is tied to star formation activity, and that supernovae and massive-star winds are the dominant accelerators., 18 pages, 4 figures; published in Nature; Version is prior to Nature's in-house style editing (differences are minimal)
- Published
- 2009