Dark Matter Limits from Dwarf Spheroidal Galaxies with the HAWC Gamma-Ray Observatory

Abstract

The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a wide field of view observatory sensitive to 500 GeV–100 TeV gamma-rays and cosmic rays. It can also perform diverse indirect searches for dark matter annihilation and decay. Among the most promising targets for the indirect detection of dark matter are dwarf spheroidal galaxies. These objects are expected to have few astrophysical sources of gamma-rays but high dark matter content, making them ideal candidates for an indirect dark matter detection with gamma-rays. Here we present individual limits on the annihilation cross section and decay lifetime for 15 dwarf spheroidal galaxies within the field of view, as well as their combined limit. These are the first limits on the annihilation cross section and decay lifetime using data collected with HAWC. We also present the HAWC flux upper limits of the 15 dwarf spheroidal galaxies in half-decade energy bins.

Searching for dark matter in the Galactic halo with a wide field of view TeV gamma-ray observatory in the Southern Hemisphere

“…With the high-dark-matter-density regions observed in astrophysical objects and the high-energy reach of astrophysical experiments, DM masses much greater than 1 TeV can be identified through their annihilation or decay products. Several experiments are currently searching for these particles [15][16][17][18][19][20][21][22][23][24] and several more are planned [25][26][27]. Nothing have been found yet but the parameter space for discovery is shrinking with time.…”

GeV-scale thermal WIMPs: Not even slightly ruled out

“…Other than CTA [157], current generation telescopes, H.E.S.S. [86,87,89,158], VERITAS (Very Energetic Radiation Imaging Telescope Array System) [159,160], MAGIC (Major Atmospheric Gamma Imaging Cherenkov Telescopes) [161][162][163], HAWC (High-Altitude Water Cherenkov Observatory) [164][165][166][167][168], DAMPE (Dark Matter Particle Explorer mission) [169], and in future LHAASO (Large High Altitude Air Shower Observatory) [170,171], will also aid eventually closing up to the unitarity limit at ∼100 TeV.…”

Gamma-Ray Dark Matter Searches in Milky Way Satellites—A Comparative Review of Data Analysis Methods and Current Results

“…HAWC has searched for dark matter annihilation and decay signals in 15 dSphs observed during 507 days between November 2014 and June 2016 [49]. They computed the average gamma-ray spectra per annihilation or decay event ( dN γ dE ) using the PYTHIA v8.2 simulation package [50], and the J-factors using the CLUMPY software package [51], assuming NFW [23] dark matter density profiles.…”

“…Results from other gamma-ray instruments are also shown (see legend for details), as well as the median and 65% and 95% symmetric quantiles of the distribution of limits obtained under the null hypothesis. Figure reproduced with permission from reference [49], ©AAS.…”