A New Eye on the VHE Transient Universe with the HAWC Online Flare Monitor

Abstract

The High Altitude Water Cherenkov (HAWC) Observatory recently began full-scale operations, surveying 2/3 of the entire sky at very high energy (VHE; E > 100 GeV). This new view of the sky offers the opportunity to detect flares from blazars, facilitating studies of the mechanisms powering their central engines and providing an avenue to constrain the properties of particles and fields in intergalactic space. The HAWC Collaboration has implemented an online flare monitor to search for rapid and extreme transient activity from a set of blazars either known or suspected to produce VHE emission. The goal of this project is to issue alerts sufficiently rapidly to form a complete multiwavelength picture of the flare. We describe the current status of the online flare monitor, demonstrating its ability to detect flares via a study of the blazars Markarian 421 and Markarian 501 in offline data.