Bremen 2017 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
EP: Fachverband Extraterrestrische Physik
EP 3: Astrophysik
EP 3.2: Talk
Monday, March 13, 2017, 16:45–17:00, GW2 B2880
HAWC High Energy Upgrade with a Sparse Array — •Vikas Joshi — Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
The High Altitude Water Cherenkov (HAWC) gamma-ray observatory has been fully operational since March 2015. It is situated on the flanks of Sierra Negra (Mexico) at an altitude of 4100 m above the sea level. HAWC consists of 300 Water Cherenkov Detectors, each containing 200 ktons of purified water and 4 PMT’s (three 8" and one 10"), that cover a total surface area of 20,000 m2. HAWC observes gamma rays in the 0.1-100 TeV energy range and has a sensitivity to TeV-scale gamma-ray sources an order of magnitude better than previous air-shower arrays. Its two steradians field-of-view and > 90% duty cycle make HAWC an ideal instrument for surveying the high-energy sky.
HAWC collects multi-TeV gamma rays with an effective area of 105 m2, but many of them are not well-reconstructed because the shower core falls outside the main array. An upgrade that increases the present fraction of well reconstructed multi-TeV showers by a factor of 3-4 can be done with a sparse outrigger array of small water Cherenkov detectors that pinpoint the core position and by that improve the angular resolution of the reconstructed showers. Such an outrigger array would be of the order of ∼300 small water Cherenkov detectors of 2.5 m3 equipped with one 8" PMT, placed over an area four times larger than HAWC. In this contribution, we will discuss the different outrigger array components and the simulation results to optimize it.