WoU-MMA:Astrophysics with a New Very-High-Energy Gamma-Ray Telescope

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Gamma-ray astronomy is a vital part of multi-messenger astrophysics (MMA), enabling robust identification or confirmation of MMA sources and strong constraints on the nature, spectra, or distance of sources. The next-generation gamma-ray observatory, the Cherenkov Telescope Array (CTA), will provide a leap forward in sensitivity. Meanwhile, an innovative high-performance telescope and camera design, the Schwarzschild-Couder Telescope (SCT), is being tested with a prototype SCT (pSCT), now in commissioning. The present project will develop calibration and analysis routines for this new very-high-energy gamma-ray telescope, the pSCT, and apply them for new measurements of the Crab Nebula, characterization of the telescope (especially for MMA follow-up), and work to measure the multi-TeV positron fraction. This group develops projects and opportunities at the intersection of research, education, and outreach. They launched and lead the Distributed Electronic Cosmic-ray Observatory (DECO), which enables citizen scientists around the world to use the DECO app on their smart phone to detect cosmic rays and other energetic particles. DECO users span 46 states, 74 countries, and seven continents. The present award supports continued operations, maintenance, and development of the DECO project. In the very-high-energy regime (>20 GeV), the current generation of imaging atmospheric Cherenkov telescopes has proven the scientific potential of the technique. The SCT promises excellent Cherenkov shower imaging capability, as well as performance in moonlight, thanks to its dual-mirror optics and high-resolution silicon-photomultiplier camera. With the calibration, reconstruction, and analysis techniques to be developed under this award, the camera will be capable of superb gamma-ray angular resolution and hadronic background rejection, both of which translate directly into scientific discovery potential. In addition, measurement of the multi-TeV positron fraction will provide essential input to identify the origin of the currently unexplained positron excess. This project advances the goals of the NSF Windows on the Universe Big Idea. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.