1. Constraints on the Emission of Gamma-Rays from M31 with HAWC
- Author
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HAWC Collaboration, Albert, A., Alfaro, R., Alvarez, C., Arteaga-Vel��zquez, J. C., Arunbabu, K. P., Rojas, D. Avila, Solares, H. A. Ayala, Belmont-Moreno, E., BenZvi, S. Y., Brisbois, C., Caballero-Mora, K. S., Capistr��n, T., Carrami��ana, A., Casanova, S., Cotti, U., Cotzomi, J., de Le��n, S. Couti��o, De la Fuente, E., de Le��n, C., Dichiara, S., Dingus, B. L., DuVernois, M. A., Engel, K., Espinoza, C., Fleischhack, H., Fraija, N., Galv��n-G��mez, A., Garc��a-Aguilar, D., Garc��a-Gonz��lez, J. A., Garfias, F., Gonz��lez, M. M., Goodman, J. A., Harding, J. P., Hernandez, S., Hona, B., Huang, D., Hueyotl-Zahuantitla, F., H��ntemeyer, P., Iriarte, A., Jardin-Blicq, A., Joshi, V., Kieda, D., Lee, W. H., Vargas, H. Le��n, Longinotti, A. L., Luis-Raya, G., Malone, K., Marinelli, S. S., Martinez, O., Martinez-Castellanos, I., Mart��nez-Castro, J., Matthews, J. A., Miranda-Romagnoli, P., Morales-Soto, J. A., Moreno, E., Mostaf��, M., Nayerhoda, A., Nellen, L., Newbold, M., Noriega-Papaqui, R., Peisker, A., P��rez-P��rez, E. G., Ren, Z., Rho, C. D., Rosa-Gonz��lez, D., Rosenberg, M., Rubenzahl, R., Salazar, H., Greus, F. Salesa, Sandoval, A., Schneider, M., Sinnis, G., Smith, A. J., Springer, R. W., Surajbali, P., Tabachnick, E., Tibolla, O., Tollefson, K., Torres, I., Villase��or, L., Wood, J., Yapici, T., Zepeda, A., and Zhou, H.
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,010504 meteorology & atmospheric sciences ,Andromeda Galaxy ,Astrophysics::High Energy Astrophysical Phenomena ,Milky Way ,Gamma ray ,FOS: Physical sciences ,Astronomy and Astrophysics ,Cosmic ray ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Galactic plane ,01 natural sciences ,Galaxy ,Interstellar medium ,Space and Planetary Science ,0103 physical sciences ,Astrophysics - High Energy Astrophysical Phenomena ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Fermi Gamma-ray Space Telescope - Abstract
Cosmic rays, along with stellar radiation and magnetic fields, are known to make up a significant fraction of the energy density of galaxies such as the Milky Way. When cosmic rays interact in the interstellar medium, they produce gamma-ray emission which provides an important indication of how the cosmic rays propagate. Gamma rays from the Andromeda Galaxy (M31), located 785 kpc away, provide a unique opportunity to study cosmic-ray acceleration and diffusion in a galaxy with a structure and evolution very similar to the Milky Way. Using 33 months of data from the High Altitude Water Cherenkov Observatory, we search for TeV gamma rays from the galactic plane of M31. We also investigate past and present evidence of galactic activity in M31 by searching for Fermi Bubble-like structures above and below the galactic nucleus. No significant gamma-ray emission is observed, so we use the null result to compute upper limits on the energy density of cosmic rays $>10$ TeV in M31. The computed upper limits are approximately ten times higher than expected from the extrapolation of the Fermi LAT results., Accepted for publication in ApJ
- Published
- 2020
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