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 $\ge$ 5 sigma 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 $1^{\circ }$ of previously detected TeV emitters, and twenty sources that are more than $1^{\circ }$ away from any previously detected TeV source. Of these twenty new sources, fourteen have a potential counterpart in the fourth \textit{Fermi} Large Area Telescope catalog of gamma-ray sources. We also explore potential associations of 3HWC sources with pulsars in the ATNF pulsar catalog and supernova remnants in the Galactic supernova remnant catalog.

20 pages, 11 figures. Matches the version published in The Astrophysical Journal. See accompanying data release at https://data.hawc-observatory.org/datasets/3hwc-survey/index.php