An updated survey of Active Galaxies with the HAWC gamma-ray observatory

TL;DR

This paper updates the survey of Active Galaxies observed with the HAWC gamma-ray observatory, including new data and analysis, leading to the detection of several sources at very high energies.

Contribution

It provides an updated, more comprehensive survey of AGNs with HAWC, including new detections and refined spectral analysis with extended data.

Findings

Detected four sources with >5σ significance: M87, Mkn 421, Mkn 501, 1ES 1215+303.

Reported eight sources with marginal detection (3-5σ), mostly BL Lac objects.

Analyzed spectra including attenuation by the Extragalactic Background Light.

Abstract

We present an update of the survey of Active Galaxies with the High Altitude Water Cherenkov (HAWC) gamma-ray observatory. This work adds 567 days of HAWC data to the previously published survey, providing a refined analysis of an updated total exposure of 2090 days. The sample includes 138 nearby AGNs from the 3FHL catalog. We fit a modified power-law to their very high energy spectra, including the exponential attenuation caused by the Extragalactic Background Light. We found four sources with significant detections (above 5$\sigma$): the radio galaxy M87 and the BL Lac objects Mkn 421, Mkn 501 and 1ES 1215+303. We also report eight sources with a marginal detection (between 3$\sigma$ and 5$\sigma$) of which seven are classified as BL Lac objects and one as a radio galaxy.