A connection between star formation activity and cosmic rays in the starburst galaxy M82 (original) (raw)

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 massivestar winds are the dominant accelerators. M 82 is a bright galaxy located approximately 12 million light years from Earth, in the direction of the Ursa Major constellation [5]. For hundreds of millions of years, M 82 has been gravitationally interacting with nearby galaxies, including the larger spiral galaxy M 81 [6]. Over time, interactions with these neighbours have deformed M 82, creating an active starburst region in its centre with a diameter of ~1000 light years [7].

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References (29)

  1. Butt, Y., "Beyond the Myth of the Supernova Remnant Origin of Cosmic Rays", Nature, 460, 701-704 (2009)
  2. Pohl, M., "On the predictive power of the minimum energy condition. 2: Fractional calorimeter behaviour in the diffuse high energy gamma emission of spiral galaxies", Astronomy and Astrophysics, 287, 453-462 (1994)
  3. Persic, M., Rephaeli, Y., Arieli, Y., "Very-high-energy emission from M 82", Astronomy and Astrophysics, 486, 143-149 (2008)
  4. de Cea del Pozo, E., Torres, D. F., Marrero, A. Y. R., "Multimessenger Model for the Starburst Galaxy M82", Astrophysical Journal, 698, 1054-1060 (2009)
  5. Sakai, S., & Madore, B. F., "Detection of the Red Giant Branch Stars in M82 Using the Hubble Space Telescope", Astrophysical Journal, 526, 599-606 (1999)
  6. Yun, M. S., Ho, P. T. P., Lo, K. Y., "A high-resolution image of atomic hydrogen in the M81 group of galaxies", Nature, 372, 530-532 (1994)
  7. Völk, H. J., Aharonian, F. A., Breitschwerdt, D., "The Nonthermal Energy Content and Gamma-Ray Emission of Starburst Galaxies and Clusters of Galaxies", Space Science Reviews, 75, 279-297 (1996)
  8. Melo, V. P., Muñoz-Tuñón, C., Maíz-Apellániz, J., & Tenorio-Tagle, G., "Young Super Star Clusters in the Starburst of M82: The Catalog", Astrophysical Journal, 619, 270 -290 (2005)
  9. Kronberg, P. P., Biermann, P., & Schwab, F. R., "The nucleus of M82 at radio and X- ray bands -Discovery of a new radio population of supernova candidates", Astrophysical Journal, 291, 693-707 (1985)
  10. Fenech, D. M., Muxlow, T. W. B., Beswick, R. J., Pedlar, A., Argo, M. K., "Deep MERLIN 5GHz radio imaging of supernova remnants in the M82 starburst", Monthly Notices of the Royal Astronomical Society, 391, 1384-1402 (2008)
  11. Rieke, G. H., Lebofsky, M. J., Thompson, R. I., Low, F. J., Tokunaga, A. T., "The nature of the nuclear sources in M82 and NGC 253", Astrophysical Journal, 238, 24-40
  12. Weiß, A., Neininger, N., Hüttemeister, S., & Klein, U., "The effect of violent star formation on the state of the molecular gas in M 82", Astronomy & Astrophysics, 365, 571-587 (2001)
  13. Blom, J. J., Paglione, T. A. D. & Carramiñana, A., "Diffuse Gamma-Ray Emission from Starburst Galaxies and M31", Astrophysical Journal, 516, 744-49 (1999)
  14. Nagai, T., "Search for TeV gamma-ray emission from nearby starburst galaxies", University of Utah Ph.D Dissertation (2005)
  15. Götting, N., "Nachweis von TeV-Gamma-Strahlung aus der Richtung der Blazare H1426+428 und 1ES1959+650 sowie der Radiogalaxie M87 mit den HEGRA- Cherenkov-Teleskopen", University of Hamburg Ph.D Dissertation (2007)
  16. Holder, J., Acciari, V. A., Aliu, E., Arlen, T., Beilicke, M., Benbow, W., Bradbury, S. M., Buckley, J. H., Bugaev, V., Butt, Y., Byrum, K. L., Cannon, A., Celik, O., Cesarini, A., Ciupik, L., Chow, Y. C. K., Cogan, P., Colin, P., Cui, W., Daniel, M. K., Ergin, T., Falcone, A. D., Fegan, S. J., Finley, J. P., Finnegan, G., Fortin, P., Fortson, L. F., Furniss, A., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Hays, E., Horan, D., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D. B., Kildea, J., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McCann, A., McCutcheon, M., Moriarty, P., Mukherjee, R., Nagai, T., Niemiec, J., Ong, R. A., Pandel, D., Perkins, J. S., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Rose, H. J., Schroedter, M., Sembroski, G. H., Smith, A. W., Steele, D., Swordy, S. P., Toner, J. A., Valcarcel, L., Vassiliev, V. V., Wagner, R., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., White, R. J., Williams, D. A., Wissel, S. A., Wood, M., Zitzer, B., "Status of the VERITAS Observatory", AIP Conference Proceedings, 1085, 657-660 (2008)
  17. Daniel, M. K., "The VERITAS standard data analysis", Proceedings of the 30 th International Cosmic Ray Conference (Merida), Universidad Nacional Autónoma de México, Mexico City, Mexico, 3, 1325-1328 (2008)
  18. Sanders, D. B., Mazzarella, J. M., Kim, D.-C., Surace, J. A.; Soifer, B. T., "The IRAS Revised Bright Galaxy Sample", Astronomical Journal, 126, 1607-1664 (2003)
  19. Wills, K. A., Pedlar, A., Muxlow, T. W. B. & Stevens, I.R., "A possible active galactic nucleus in M82?", New Astronomy Reviews, 43, 633-637 (1999)
  20. Klein, U., Wielebinski, R., Morsi, H. W., "Radio continuum observations of M82", Astronomy and Astrophysics, 190, 41-46 (1988)
  21. Strickland, D. K., & Heckman, T. M., "Iron Line and Diffuse Hard X-Ray Emission from the Starburst Galaxy M82", Astrophysical Journal, 658, 258-281 (2007)
  22. -van der Kruit, P. C., "Observations of core sources in Seyfert and normal galaxies with the Westerbork synthesis radio telescope at 1415 MHz.", Astron. Astrophys. 15, 110-122 (1971);
  23. Helou, G., Soifer, B. T., Rowan-Robinson, M., "Thermal infrared and nonthermal radio -Remarkable correlation in disks of galaxies", Astrophysical Journal Letters, 298, L7-L11 (1985).
  24. -Condon, J.J. "Radio emission from normal galaxies", Annual review of astronomy and astrophysics, 30, 575-611. (1992)
  25. -Voelk, H.J., "The correlation between radio and far-infrared emission for disk galaxies -A calorimeter theory", Astron. Astrophys. 218, 67-70. (1989);
  26. Helou, G., and Bicay, M. D., "A physical model of the infrared-to-radio correlation in galaxies", Astrophysical Journal, 415, 93-100 (1993);
  27. Groves, B.A., Cho, J., Dopita, M., Lazarian, A., "The Radio-FIR Correlation: Is MHD Turbulence the Cause?", Publ. of the Astron. Soc. Australia, 20, 252-256 (2003)
  28. Berge, D., Funk, S., Hinton, J., "Background modelling in very-high-energy γ-ray astronomy", Astronomy and Astrophysics, 466, 1219-1229 (2007)
  29. Helene, O., "Upper limit of peak area", Nuclear Instruments and Methods in Physics Research, 212, 319-322 (1983)