2021/07/30 by P. Surajbali, Surajbali, Pooja
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2107.14553
openalex publication_date 2021/07/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Fermi bubbles are structures observed in gamma rays at GeV energies,\nemanating from the central region of our galaxy and extending up to 8.5 kpc\nabove and below the galactic plane. While initial studies showed a flat\nbrightness across the entire structure, more recent work found a brightening at\nthe base. We perform a template-based search for TeV signals from the northern\nFermi bubble and just from the base of it in data from the High Altitude Water\nCherenkov (HAWC) gamma-ray observatory. We employ a profile likelihood approach\nto calculate the significance and flux from the search regions. With no\nsignificant signal from the northern Fermi bubble and its base, we report new\nupper limits on the integral flux at 95% confidence level. Our integral flux\nupper limits for the northern Fermi bubble are more constraining than the\nprevious limits reported by HAWC. Moreover, we present, for the first time, TeV\nlimits pertaining to the base of the bubble which constitutes a more fair\ncomparison to Fermi Large Area Telescope data points close to this particular\nregion.\n