PI: Chip Kobulnicky, University of Wisconsin, firstname.lastname@example.org
Address: 475 N. Charter St., Madison, WI 53706, USA
CoI: Kelsey Johnson, NRAO/University of Wisconsin
Title: SQUID Imaging of Ultra-Young Radio-Selected Star Clusters in Nearby Galaxies
Abstract: Ultra-young, compact star clusters with probable ages <1 Myr have recently been identified in several nearby galaxies using radio-wave interferometers to detect free-free emission from their dense \HII\ regions. We are proposing a SQUID JHKL survey of this radio-selected population in order to \bf 1) image the ultra-young clusters in the near-IR to measure their colors and luminosities, which in many cases, are heavily obscured, \bf 2) measure the \it sizes of the stellar clusters which are expected to be ~4 pc (0.15\arcsec - 0.8\arcsec), and \bf 3) measure the amount of dust extinction to each source. For the youngest star clusters, multi-color data may permit independent age and extinction estimates. We will compare the sizes and extinctions of the ultra-young radio-selected sample to optically- selected samples in the literature to analyze how the sizes and dust optical depths evolve with cluster age. This proposal is a pilot study to image a sample of star clusters at the extreme young end of the age spectrum in order to understand the earliest evolutionary phases of massive cluster formation and the birth environments that produce them.
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