Cosmic Ray Physics with HAWC

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

This project will advance the understanding of cosmic rays, enigmatic particles from space that continuously bombard our planet. Cosmic rays carry valuable information about the nature of the universe, and unlocking their secrets is crucial for understanding their origin and journey from their sources to Earth. The project aims to analyze nearly a decade of data collected by the High Altitude Water Cherenkov (HAWC) Observatory in Mexico to create detailed maps of the cosmic ray arrival direction distribution. By studying cosmic ray anisotropy and integrating it with their energy spectrum and mass composition, the project can uncover insights into their propagation across the Milky Way and pinpoint the potential existence of a nearby source. This knowledge is also crucial for unraveling the properties of astrophysical plasmas in the interstellar medium, including the very local environment, such as the heliosphere. Through outreach efforts, including engagement with underrepresented communities and the development of educational programs, the project will inspire the next generation of scientists and foster a diverse and inclusive scientific community. The research analyzes cosmic ray data collected by the HAWC Observatory to study cosmic ray anisotropy. Cosmic rays, high-energy particles originating from distant unresolved sources, pose numerous challenges in their study due to the poorly understood acceleration mechanisms and interactions with magnetic fields while propagating in space. The analysis aims to produce high-resolution sky maps of cosmic ray arrival direction distribution across a wide energy range (1-100 TeV) and investigate its temporal stability, energy spectral features, and angular structure. Combining data from HAWC and IceCube will provide all-sky maps of cosmic ray anisotropy from 10 TeV to 100 TeV, enabling unprecedented insights into their origins and propagation mechanisms. The research will contribute to advancements in understanding the properties of interstellar magnetized plasma turbulence. This knowledge will help uncover the mechanisms behind cosmic ray acceleration and propagation, shedding light on the nature of their galactic sources and the structure of the interstellar medium. Furthermore, the study of cosmic ray anisotropy has practical implications, such as space weather forecasting and radiation protection for astronauts. The project takes advantage of the large data volume available to develop analyses and investigate the origin of the observation, promoting the education and outreach goals by exposing students to scientific research and educating the next generation of scientists. In addition, the published results will be relevant to study the heliosphere's effects on TeV cosmic rays reaching Earth from space. 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.