From MILAGRO to HAWC : perspectives for VHE gamma ray astronomy

by Dr Antonio Marinelli (Physics department of Universidad Nacional Autonoma de Mexico IF-UNAM)

Tuesday 3 Jul 2012, 15:00 → 16:30 Europe/Rome

250 (INFN Edificio C)

HAWC (High Altitude Water Cherenkov) is a gamma ray observatory composed by 300 water Cherenkov detectors instrumented with 4 facing up photomultiplayers at 4100 meters of elevation respect to the sea level (close to the volcano Sierra Negra in Puebla, Mexico). The HAWC concept builds upon the experience of MILAGRO gamma-ray telescope that was located in Los Alamos (New Mexico, USA). MILAGRO was the first large, uniformly instrumented, air shower array using water Cherenkov technology and it was operating from 2000 to 2008. MILAGRO was able to observe galactics sources, as the Cygnus region or the Crab nebula, and extragalactic sources, as Markarian 421, giving important hints about the physical properties of these objects. The HAWC observatory will give to the scientific community a high sensitivity survey of the gamma ray sky in the energy range from 100 GeV to 100 TeV. HAWC will be 15 times more sensible than MILAGRO because of its higher elevation respect to the sea level, its larger area and the greater optical isolation of the PMTs. A first construction stage, VAMOS, consisting of 7 of the 300 detectors of HAWC was finished in 2011. The main goal of VAMOS was to define the ultimate HAWC design. HAWC construction is planned to be finished by the end of 2014, however the first scientific results are expected in the spring 2013 when HAWC will be already instrumented with 100 water Cherenkov detectors. The complete HAWC will be a second generation wide field gamma ray telescope that will be synergistic with IACTs, neutrino detectors and especially the Fermi gamma ray telescope. We expect important improvements on the knowledge of galactic point sources and diffuse gamma ray emission, AGN steady and transient phenomena, GRB prompt emission, dark matter annihilation and high energy solar activity.