The Evolved Red Stellar Content of M32

Abstract

Near-infrared images obtained with the CFHT AOB are used to investigate the stellar content of the Local Group elliptical galaxy M32. Observations of a field 2.3 arcmin from the galaxy center reveal a large population of AGB stars, and comparisons with models indicate that these objects have an age log(t_Gyr) < 9.3. It is concluded that intermediate age stars account for roughly 25% of the total K light and 10% +/- 5% of the mass in this field. The K LF of bright sources between 20 and 30 arcsec from the nucleus is well matched by the LF of the outer regions of the galaxy after accounting for differences in surface brightness and correcting for crowding. It is concluded that the relative size of the intermediate age component with respect to other populations does not change with radius over most of the galaxy. However, the integrated J-K color and 2.3 micron CO index change with radius within a few tenths of an arcsec of the galaxy center indicating that, contrary to what might be inferred from observations at visible wavelengths, the integrated photometric properties of the central regions of M32 differ from those of the surrounding galaxy.

18 pages, 9 postscript figures, to appear in the PASP

References in corpus (1)

• Near-Infrared Adaptive Optics Imaging of the Central Regions of Nearby Sc Galaxies: I. M33

Cited by in corpus (21)

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• A new formation model for M32: A threshed early-type spiral?
• Evidence for an outer disk in the Prototype `Compact Elliptical' Galaxy M32
• An Upper Limit to the Age of the Galactic Bar
• Radial Age and Metal Abundance Gradients in the Stellar Content of M32
• Globular Clusters and the Mira Period-Luminosity Relation
• The Brightest AGB Stars in the Inner Bulge of M31
• WIYN Survey for Carbon Stars in the M31 and Cetus Dwarf Spheroidal Galaxies: Evolutionary Implications
• The Recent Stellar Archeology of M31 - The Nearest Red Disk Galaxy
• The Cosmological Significance of High-Velocity Cloud Complex H
• Probing the Central Regions of Nearby Compact Elliptical Galaxies
• The Detection of Bright Asymptotic Giant Branch Stars in the Nearby Elliptical Galaxy Maffei 1
• The Upper Asymptotic Giant Branch of the Elliptical Galaxy Maffei 1, and Comparisons with M32 and NGC 5128
• Deep ALTAIR + NIRI Imaging of the Disk and Bulge of M31
• The Peak Brightness and Spatial Distribution of AGB Stars Near the Nucleus of M32
• Anomalous Surface Brightness Fluctuations in NGC 4489
• The Brightest Stars in M32: Comparing Predictions from Spectra with the Resolved Stellar Content
• The Young Outer Disk of M83
• Seeing Red in M32: Constraints on the Stellar Content from Near- and Mid-Infrared Observations and Applications for Studies of More Distant Galaxies
• Photometric Variability Among the Brightest Asymptotic Giant Branch Stars Near the Center of M32