Performance Enhancement of the HAWC Gamma-ray Observatory Using the Outrigger Array

The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a ground-based air shower array designed to detect Cherenkov light produced in water by secondary particles from atmospheric air showers. In order to improve the sensitivity at the highest energies, especially for showers with cores falling outside the main array, an outrigger array of 345 smaller Water Cherenkov Detectors (WCDs) was installed around the main array. This extension increases the instrumented area of HAWC by a factor of four and improves the containment of high energy showers. The outrigger array significantly improves HAWC's sensitivity above 10 TeV as well as its angular and energy resolution. In this contribution, we will present the current status and the performance of the upgrade.