3HWC: The Third HAWC Catalog of Very-high-energy Gamma-Ray Sources

Abstract

We present a new catalog of TeV gamma-ray sources using 1523 days of data from the High-Altitude Water Cherenkov (HAWC) Observatory. The catalog represents the most sensitive survey of the northern gamma-ray sky at energies above several TeV, with three times the exposure compared to the previous HAWC catalog, 2HWC. We report 65 sources detected at ≥5σ significance, along with the positions and spectral fits for each source. The catalog contains eight sources that have no counterpart in the 2HWC catalog, but are within 1° of previously detected TeV emitters, and 20 sources that are more than 1° away from any previously detected TeV source. Of these 20 new sources, 14 have a potential counterpart in the fourth Fermi Large Area Telescope catalog of gamma-ray sources. We also explore potential associations of 3HWC sources with pulsars in the Australia Telescope National Facility (ATNF) pulsar catalog and supernova remnants in the Galactic supernova remnant catalog.

Search for TeV decaying dark matter from the Virgo cluster of galaxies

“…Virgo HAWC DM Figure 1: The point-source significance map around the Virgo cluster region using 1523 days of HAWC data with pass 4 reconstruction and the methods used in Ref. [5]. The positions of the two main sub-clusters used in this analysis M87 and M49 are labelled.…”

A GeV to TeV view of shell-type SNRs

“…Using the HAWC significance maps upon which the 3HWC catalog [2] was based, SNRs were selected that did not overlap with regions where HAWC detects significant gamma-ray emission.…”

“…The same dataset was used for 3HWC, the third HAWC catalog. More details about the dataset can be found in [2]. HAWC-internal software was used for data reduction (calibration, event reconstruction, background rejection, and binning).…”

“…The systematic uncertainties due to the modeling of the HAWC detector were taken into account as described in [2], with the addition of the systematic uncertainty due to the source spectrum assumed in the preparation of the detector response file. For point sources, we also accounted for HAWC's systematic pointing uncertainty by letting the source positions float within the uncertainty and profiling over the source position when calculating the upper limit.…”

“…HAWC is a large-field-of-view gamma-ray observatory sensitive in the energy range from hundreds of GeV to hundreds of TeV. HAWC has been surveying the northern TeV gamma-ray sky since 2015 and in its latest catalog reports 65 gamma-ray sources [2].…”