NOAO >   Observing Info >   Approved Programs >   2007A-0057

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Proposal Information for 2007A-0057


PI: Joshua D. Simon, Caltech, jsimon@astro.caltech.edu
Address: Department of Astronomy, 1200 E. California Blvd, MS 105-24, Pasadena, CA 91125, USA

CoI: Alberto Bolatto, UC Berkeley
CoI: Kristine Spekkens, Rutgers

Title: Cusps vs. Cores - The Distribution of Dwarf Galaxy Density Profile Slopes

Abstract: We propose to obtain 2D \ha velocity fields of a sample of 10 nearby dwarf galaxies using the DensePak IFU at the WIYN telescope. Our work to date has shown a wide range of dark matter density profiles in nearby dwarfs, contrary to the predictions of the Cold Dark Matter (CDM) model. With this new study, we will address three major questions: (1) What is the distribution of density profile slopes? (2) What is the significance of the non-circular motions that we find to be nearly ubiquitous even in regular, unbarred galaxies? (3) Are there any correlations between density profile shapes and other galaxy properties? These observations will enable us to study the internal kinematics of our targets with 4\arcsec (60-200 pc) angular resolution and ~1 km/s velocity uncertainties. The DensePak data represent a dramatic improvement over most previous work; the spatial resolution, spectral resolution, and the number of independent velocity data points will be up to an order of magnitude better, allowing us to carry out a crucial test of CDM simulations with unprecedented precision.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2007A-0057

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