Galaxy Evolution Explorer observations of the ultraviolet surface brightness and color profiles of the local group elliptical galaxy M32 (NGC 221)

被引:10
作者
de Paz, AG
Madore, BF
Sohn, YJ
Lee, YW
Seibert, M
Rich, RM
Bianchi, L
Barlow, TA
Byun, YI
Donas, J
Forster, K
Friedman, PG
Heckman, TM
Jelinsky, P
Malina, RF
Martin, DC
Milliard, B
Morrissey, P
Neff, SG
Schiminovich, D
Siegmund, OHW
Small, T
Szalay, AS
Welsh, BY
Wyder, TK
机构
[1] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA
[2] Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea
[3] CALTECH, Pasadena, CA 91125 USA
[4] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA
[5] Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA
[6] Lab Astrophys Marseille, F-13376 Marseille 12, France
[7] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA
[8] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA
[9] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA
关键词
galaxies : elliptical and lenticular; cD; galaxies : fundamental parameters; galaxies : individual (M32); Local Group; ultraviolet : galaxies;
D O I
10.1086/422470
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
M32, the compact elliptical galaxy companion to the Andromeda spiral galaxy, has been imaged by the Galaxy Evolution Explorer (GALEX) in two UV bands, centered at similar to1500 (far-ultraviolet [FUV]) and 2300 Angstrom (near- ultraviolet). 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 its very low UV upturn, M32 has similar UV properties to those observed in luminous elliptical galaxies.
引用
收藏
页码:L115 / L118
页数:4
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