Gamma astronomy with the ARGO-YBJ experiment

Very High Energy (VHE) gamma-astronomy and cosmic ray physics are the main goals of the ARGO-YBJ experiment. The detector is located in Tibet (People's Republic of China) and is a full coverage Extensive Air Shower array consisting of a carpet of Resistive Plate Chambers (RPCs). Altitude and full coverage ensure an energy threshold of few hundreds of GeV for primary photons detected in shower mode, while the RPC time resolution gives a good pointing accuracy, thus allowing a high sensitivity to g -ray sources. The large eld of view (FoV) and the high duty-cycle allow the continuous monitor of the Northern sky in the declination band (-10, +70 degrees). The detector operates also in scaler mode in order to look for Gamma Ray Burst (GRB) signals in the range 1-100 GeV in coincidence with GRB detection by satellites. After some detail about the performances of the detector, the present results concerning gamma-astronomy will be presented.