This is a collaborative award to support the scientists who will work on the construction, commissioning and initial analysis of data from the High Altitude Water Cherenkov (HAWC) gamma-ray observatory being built at the Sierra Negra in Mexico. The HAWC collaboration consists of 14 US and 11 Mexican institutions. The observations of HAWC will probe the most extreme environments in the Universe, providing a unique view of non-thermal processes in the Galaxy and beyond. The key science goals of HAWC are to: (a) Measure the spectrum of Galactic sources to the highest energies; (b) Map the Galactic diffuse gamma-ray emission from 1 TeV to 100 TeV, measuring the cosmic-ray flux and spectrum across the Galaxy; (c) Study transient emission from active galactic nuclei (AGN); (d) Monitor the sky for 100 GeV emission from gamma-ray bursts; and (e) Search for new TeV physics with HAWC's unbiased sky survey. HAWC measurements have the potential to shed light on the fundamental symmetries of nature, including the search for Lorentz violation at extreme energies, the search for the dark matter in the universe, and the direct detection of massive relic particles. HAWC is a water Cherenkov air-shower detector consisting of 300 large water tanks. The tanks will be densely packed to cover an area of about 20,000 square meters. The goal is to begin taking data while the array is under construction and to have the full detector online within approximately three years.
Broader Impacts: HAWC is an all-sky instrument that will serve as a TeV "finder" telescope for Imaging Atmospheric Cherenkov Telescopes (IACTs) and IceCube and will have the sensitivity to extend the measurement of satellite-discovered sources to TeV. HAWC will build on the strong outreach record of Milagro to bring this exciting field of research to students and the general public. Since HAWC is a joint US-Mexican project, this will be an excellent opportunity to attract talented Hispanic students to the field of Particle Astrophysics and to Physics in general. The project has developed an outreach video about HAWC and web materials about HAWC and Particle Astrophysics in both Spanish and English.
The High-Altitude Water Cherenkov detector, or HAWC, is currently under construction on the flanks of the Sierra Negra volcano near Puebla, Mexico. HAWC is designed to observe high-energy gamma rays and cosmic rays coming from the most extreme environments in the known universe, such as supernova explosions, active galactic nuclei and gamma-ray bursts (GRBs). It is believed that gamma rays are correlated with the acceleration sites of charged cosmic rays, whose origins have been a mystery for nearly 100 years. More details about HAWC can be found on its public webpage at http://private.hawc-observatory.org/hawc.umd.edu/. This proposal funded a postdoctoral research scientist for one year to work on HAWC at the beginning of construction. The postdoc is also a member of the Swift collaboration, which is a satellite that studies GRBs. During that time the following items were accomplished: Published 3 papers concerning GRBs using Swift data and sent out several GRB Coordinate Network (GCN) alerts. Worked on electronics for determining timing information using GPS units. Developed software for use by the HAWC collaboration such as a database to keep track of electronics inventory and a webpage for collaborators to check the status of the detector when doing data taking shifts. The PIs and postdoc travelled to two HAWC collaboration meetings and one international conference to disseminate information about their contributions to the HAWC and Swift experiments.
