Searching for TeV DM evidence from Dwarf Irregular Galaxies with the HAWC Observatory

Abstract

The dynamics of dwarf irregular (dIrr) galaxies are observed to be dominated by dark matter (DM). Recently, the DM density distribution has been studied for 31 dIrrs. Their extended DM halo (Burket type profile) makes these objects good candidates for DM searches. Located in Puebla (Mexico), the High Altitude Water Cherenkov (HAWC) Observatory is an optimal instrument to perform such DM searches, because of its large sky coverage (8.4 sr per day). We analyzed a set of two years of HAWC data and we found no significant DM signal from dIrr galaxies. We present the upper limits for DM annihilation cross-section with dIrr galaxies.

Dark Matter searches towards the WLM dwarfirregular galaxy with H.E.S.S.

“…In the case of a continuum spectrum, the most constraining limits are given by the τ + τ − channel with a σ v ∼ 10 −21 cm 3 .s −1 at a DM mass of 1TeV. The upper limits derived in this work improve of a factor of 10 to almost 100 compared to those obtained by the HAWC experiment [1].…”

“…These objects are rotationally supported with relatively simple kinematics. They are assumed to be dark matter dominated objects at all radii, even in their central part [1]. dIrrs offer the advantage to have well-constrained rotation curve which leads to an actual measured J factor (not a prediction) with very small uncertainties.…”

“…Another property of these dwarf galaxies is their star-forming region, below 0.1 • , at their center. The HAWC experiment published a study of irregular galaxies [1] and set limits on the DM annihilation cross section using these galaxies. In 2018, the H.E.S.S.…”

Multimessenger Multi-TeV Dark Matter

“…In the left panel of Fig. 2 we show the preliminary study of the HAWC collaboration on this new class of targets for the analysis of 1-year of data taking [118]. Although the results do not reach the thermal annihilation cross-section value and bounds are not competitive with respect to those obtained at lower WIMP mass scales, they represent new results for the TeV DM candidate by means of a previously unexplored kind of DM targets, i.e.…”

“…Left Panel:Figure from[118]. Constraints on the DM mass and annihilation cross-section by the study of several dwarf irregular galaxies at TeV energy scale, with 1-year of data of the HAWC observatory.…”