Constraints on the Emission of Gamma Rays from M31 with HAWC
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 TeV in M31. The computed upper limits are approximately ten times higher than expected from the extrapolation of the Fermi LAT results.
Keywords
Cite
@article{arxiv.2001.04065,
title = {Constraints on the Emission of Gamma Rays from M31 with HAWC},
author = {HAWC Collaboration and A. Albert and R. Alfaro and C. Alvarez and J. C. Arteaga-Velázquez and K. P. Arunbabu and D. Avila Rojas and H. A. Ayala Solares and E. Belmont-Moreno and S. Y. BenZvi and C. Brisbois and K. S. Caballero-Mora and T. Capistrán and A. Carramiñana and S. Casanova and U. Cotti and J. Cotzomi and S. Coutiño de León and E. De la Fuente and C. de León and S. Dichiara and B. L. Dingus and M. A. DuVernois and K. Engel and C. Espinoza and H. Fleischhack and N. Fraija and A. Galván-Gámez and D. García-Aguilar and J. A. García-González and F. Garfias and M. M. González and J. A. Goodman and J. P. Harding and S. Hernandez and B. Hona and D. Huang and F. Hueyotl-Zahuantitla and P. Hüntemeyer and A. Iriarte and A. Jardin-Blicq and V. Joshi and D. Kieda and W. H. Lee and H. León Vargas and A. L. Longinotti and G. Luis-Raya and K. Malone and S. S. Marinelli and O. Martinez and I. Martinez-Castellanos and J. Martínez-Castro and J. A. Matthews and P. Miranda-Romagnoli and J. A. Morales-Soto and E. Moreno and M. Mostafá and A. Nayerhoda and L. Nellen and M. Newbold and R. Noriega-Papaqui and A. Peisker and E. G. Pérez-Pérez and Z. Ren and C. D. Rho and D. Rosa-González and M. Rosenberg and R. Rubenzahl and H. Salazar and F. Salesa Greus and A. Sandoval and M. Schneider and G. Sinnis and A. J. Smith and R. W. Springer and P. Surajbali and E. Tabachnick and O. Tibolla and K. Tollefson and I. Torres and L. Villaseñor and J. Wood and T. Yapici and A. Zepeda and H. Zhou},
journal= {arXiv preprint arXiv:2001.04065},
year = {2020}
}
Comments
Accepted for publication in ApJ