The M31 dwarf spheroidal companion Andromeda V:: g′, r′, and i′ imaging with the Gemini Multi-Object Spectrograph on Gemini North

被引:11
作者
Davidge, TJ
Da Costa, GS
Jorgensen, I
Allington-Smith, JR
机构
[1] Natl Res Council Canada, Herzberg Inst Astrophys, Canadian Gemini Off, Victoria, BC V9E 2E7, Canada
[2] Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia
[3] Australian Natl Univ, Mt Stromlo Observ, Weston, ACT 2611, Australia
[4] No Operat Ctr, Gemini Observ, Hilo, HI 96720 USA
[5] Univ Durham, Dept Phys, Sci Labs, Durham DH1 3LE, England
关键词
galaxies : dwarf; galaxies : individual (Andromeda V); galaxies : stellar content Local Group;
D O I
10.1086/341645
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Images obtained in g', r, and i' with the Gemini Multi-Object Spectrograph (GMOS) on Gemini North are used to investigate the metallicity and stellar content of the M31 dwarf spheroidal companion galaxy Andromeda V. Red giant branch (RGB) stars are traced out to radii in excess of 126" from the galaxy center, indicating that And V extends over a diameter approaching 1 kpc. The mean g'-i' color of the RGB does not change with radius. Based on the slope of the RGB in the (i', g'-i') color-magnitude diagram, we conclude that the metallicity of And V is [Fe/H] = -2.2 +/- 0.1. This is lower than earlier estimates and places And V squarely on the relation between metallicity and integrated brightness defined by other dwarf spheroidal and dwarf elliptical galaxies. In contrast to many of the Galaxy's dwarf spheroidal companions, there is no evidence for a statistically significant population of luminous asymptotic giant branch stars near the center of the galaxy.
引用
收藏
页码:886 / 895
页数:10
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