NOAO >   Observing Info >   Approved Programs >   2013A-0528

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Proposal Information for 2013A-0528


PI: Ronald Marzke, San Francisco State University, marzke@sfsu.edu
Address: Physics Department, 1600 Holloway Ave, San Francisco, CA 94132, USA

CoI: Russell Lego, San Francisco State University
CoI: Casey Moore, San Francisco State University
CoI: Luiz Nicolaci da Costa, Observatorio Nacional, Brazil
CoI: Marcio Maia, Observatorio Nacional, Brazil

Title: Spectroscopic Confirmation of Candidate Compact Elliptical Galaxies and Ultracompact Dwarfs identified in UKIRT Infrared Deep Sky Survey

Abstract: We propose spectroscopic confirmation of candidate compact- elliptical galaxies and ultra-compact dwarfs detected in the UKIRT Infrared Deep Sky Survey. By combining UKIDSS JK imaging with ugriz imaging from the Sloan Digital Sky Survey, we have identified compact sources whose surface brightness profiles are poorly distinguished from foreground stars but whose colors distinguish them as composite stellar populations. The depth of UKIDSS is well matched to the SDSS for evolved, low-redshift stellar populations, and the broad wavelength baseline allows a particularly clean distinction between individual stars and stellar populations in color space. This clean distinction allows us to search for compact stellar systems at greater distances and in a wider range of environments than were previously accessible. Here, we request one night at the KPNO 4m to measure redshifts of these candidates with RCSPEC. Our small sample represents a first step toward an unbiased sample of compact stellar systems based on wide-field near- IR and optical imaging. Because such galaxies are so rare and because so few have been identified, this small but unbiased sample has the potential to place important constraints on the abundance of galaxies at the nexus between compact elliptical galaxies and ultra-compact dwarfs.


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NOAO >   Observing Info >   Approved Programs >   2013A-0528

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