Collaborative Research: Charting the Supernova-Gas-Stars Connection via a Major New VLA Survey of the Local Group

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Stars form from interstellar gas. In present-day galaxies, most of that interstellar gas is atomic gas, called HI gas. Despite decades of study, major mysteries still surround the interaction of HI, supernova explosions, and massive young stars. The investigators are conducting a major new survey using the NSF's Very Large Array (VLA). They are using the VLA to better measure the structure of HI and radio emission from the nearby galaxies. The investigators will answer a series of key questions about galaxies’ stellar life cycles. The investigators study how ``stellar nurseries'' of cold, opaque gas form. At the end of the short lives of massive stars, supernova explosions shape the gas in galaxies, and the investigators will measure the resulting the interstellar turbulence seen in galaxies. The research program will have a broad societal impact through planetariums shows, a citizen science project, and a suite of hands-on tutorials aimed at students at the middle school, high school, and college levels. This proposal will address these questions by supporting the observation, processing, and scientific analysis of the Local Group L-Band Survey (LGLBS): a major new Karl G. Jansky Very Large Array (VLA) survey of the Local Group of galaxies. This survey uses 1,800 hours of VLA time to observe the six northern Local Group star-forming galaxies, including Andromeda, with an unprecedented combination of spatial resolution, spectral resolution, bandwidth, and sensitivity. LGLBS simultaneously covers the 21-cm line, which traces HI, and the 1--2 GHz radio continuum emission, which traces past SN explosions and warm gas around massive stars. These are the only galaxies close enough that the VLA can resolve the interactions between the interstellar medium (ISM), star formation, and stellar feedback. 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.