Contribution Poster (A0 portrait)
First light of the HAWC high energy upgrade
The High Altitude Water Cherenkov (HAWC) γ-ray observatory is fully operational since march 2015 in central Mexico. It is a Water Cherenkov Detector (WCD) consisting of 300 tanks filled with purified water, each instrumented with 4 photomultiplier tubes. They record, via the cherenkov light produced in the water, the secondary particles from atmospheric air showers of energy ranging from 0.1 to 100 TeV. Its sensitivity to TeV γ-ray sources is one order of magnitude better than the previous generation of WCD. HAWC is currently undergoing a major upgrade with the addition of a sparse array of 345 smaller tanks around the main array, extending the current instrumented area from 22500 m2 to 100000 m2. The main objective is to enable accurate reconstruction of multi-TeV showers whose core and footprint is not well contained inside the main array. We will present the status of the HAWC upgrade as well as the first data and the improvement in sensitivity achieved with the upgraded version.