GALEX observations of the UV surface brightness and color profiles of the Local Group elliptical galaxy M32 (NGC221)

Abstract

M32, the compact elliptical-galaxy companion to the Andromeda spiral galaxy has been imaged by the Galaxy Evolution Explorer (GALEX) in two ultraviolet bands, centered at ~1500 (FUV) and 2300 Angstroms (NUV). The imaging data have been carefully decomposed so as to properly account for the complicated background contamination from the disk of M31. We have derived the surface brightness and color profiles finding a slightly positive color gradient of Delta(FUV-B)/Delta log(r)=+0.15+/-0.03 within one effective radius. Earlier data from the Ultraviolet Imaging Telescope suggested that M32 had an extremely large (negative) FUV-optical color gradient (Delta(FUV-B)/Delta log(r)<-2), inverted with respect to the majority of gradients seen in giant elliptical galaxies. Our new results show that, despite of its very low UV-upturn, M32 has similar UV properties to those observed in luminous elliptical galaxies.

arXiv comment5 pages, 3 figures. This paper will be published as part of the Galaxy Evolution Explorer (GALEX) Astrophysical Journal Letters Special Issue. Links to the full set of papers will be available at http://www.galex.caltech.edu/PUBLICATIONS/ after November 22, 2004

References in corpus (11)

• The On-Orbit Performance of the Galaxy Evolution Explorer
• Far-Ultraviolet Radiation from Elliptical Galaxies
• Tidal Interaction of M32 and NGC 205 with M31: Surface Photometry and Numerical Simulations
• A Far Ultraviolet Analysis of the Stellar Populations in Six Elliptical and S0 Galaxies
• Detection and Photometry of Hot Horizontal Branch Stars in the Core of M32
• Hubble Space Telescope Observations of M32: The Color-Magnitude Diagram
• Evidence for an outer disk in the Prototype `Compact Elliptical' Galaxy M32
• Systematics of the Ultraviolet Rising flux in a GALEX/SDSS sample of Early-type Galaxies
• Far-Ultraviolet Color Gradients in Early-Type Galaxies
• The far-ultraviolet emission of early-type galaxies
• A detailed two-dimensional stellar population study of M32

Cited by in corpus (8)

• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• The GALEX Ultraviolet Atlas of Nearby Galaxies
• The UV, Optical, and IR Properties of SDSS Sources Detected by GALEX
• Using [CII] 158 micron Emission From Isolated ISM Phases as a Star-Formation Rate Indicator
• A new reference catalogue for the very metal-poor Universe: +150 OB stars in Sextans A
• The Brightest Stars in M32: Comparing Predictions from Spectra with the Resolved Stellar Content
• The Case for Thermalization as a Contributor to the [CII] Deficit
• A critical review of the evidence for M32 being a compact dwarf satellite of M31 rather than a more distant normal galaxy