Numerical Color-Magnitude Diagram Analysis of SDSS Data and Application to the New Milky Way satellites

Abstract

We have tested the application to Sloan Digital Sky Survey data of the software package MATCH, which fits color-magnitude diagrams (CMDs) to estimate stellar population parameters and distances. These tests on a set of six globular clusters show that these techniques recover their known properties. New ways of using the CMD-fitting software enable us to deal with an extended distribution of stars along the line-of-sight, to constrain the overall properties of sparsely populated objects, and to detect the presence of stellar overdensities in wide-area surveys. We then also apply MATCH to CMDs for twelve recently discovered Milky Way satellites to derive in a uniform fashion their distances, ages and metallicities. While the majority of them appear consistent with a single stellar population, CVn I, UMa II, and Leo T exhibit (from SDSS data alone) a more complex history with multiple epochs of star formation.

25 pages, 20 figures, subsection added including 4 new figures, some other textual changes, accepted for publication in the Astronomical Journal

References in corpus (5)

• The Kinematics of the Ultra-Faint Milky Way Satellites: Solving the Missing Satellite Problem
• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
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• A deep Large Binocular Telescope view of the Canes Venatici I dwarf galaxy
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Cited by in corpus (5)

• The structural properties and star formation history of Leo T from deep LBT photometry
• The Star Formation History and Extended Structure of the Hercules Milky Way Satellite
• A Deep Survey of the Fornax dSph I: Star Formation History
• Variable Stars in the Newly Discovered Milky Way Dwarf Spheroidal Satellite Canes Venatici I
• The Age and Metallicity of the Bootes I System