# The 2HWC HAWC Observatory Gamma Ray Catalog

## TL;DR

This paper presents the first catalog of TeV gamma-ray sources detected by the HAWC observatory, showcasing its sensitivity and continuous sky monitoring capabilities, resulting in 39 detected sources including many new discoveries.

## Contribution

It provides the first comprehensive catalog of TeV gamma-ray sources from the completed HAWC observatory, with detailed source measurements and new source identifications.

## Key findings

- 39 sources detected with high significance
- 16 sources are new and not previously reported in TeV catalogs
- HAWC's sensitivity allows for continuous sky monitoring at TeV energies

## Abstract

We present the first catalog of TeV gamma-ray sources realized with the recently completed High Altitude Water Cherenkov Observatory (HAWC). It is the most sensitive wide field-of-view TeV telescope currently in operation, with a 1-year survey sensitivity of ~5-10% of the flux of the Crab Nebula. With an instantaneous field of view >1.5 sr and >90% duty cycle, it continuously surveys and monitors the sky for gamma ray energies between hundreds GeV and tens of TeV. HAWC is located in Mexico at a latitude of 19 degree North and was completed in March 2015. Here, we present the 2HWC catalog, which is the result of the first source search realized with the complete HAWC detector. Realized with 507 days of data and represents the most sensitive TeV survey to date for such a large fraction of the sky. A total of 39 sources were detected, with an expected contamination of 0.5 due to background fluctuation. Out of these sources, 16 are more than one degree away from any previously reported TeV source. The source list, including the position measurement, spectrum measurement, and uncertainties, is reported. Seven of the detected sources may be associated with pulsar wind nebulae, two with supernova remnants, two with blazars, and the remaining 23 have no firm identification yet.