The shell game: a panoramic view of Fornax
The shell game: a panoramic view of Fornax
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DOI：
10.1093/mnras/stv1684
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发表时间：
2015-07
影响因子：
4.8
通讯作者：
N. Bate;N. Bate;B. McMonigal;G. F. Lewis;M. Irwin;E. González-Solares;T. Shanks;Nigel Metcalfe-Nigel-Metc
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文献类型：
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作者：
N. Bate;N. Bate;B. McMonigal;G. F. Lewis;M. Irwin;E. González-Solares;T. Shanks;Nigel Metcalfe-Nigel-Metc
我们提出了一个全景研究的天炉座矮球状星系，使用的数据作为VLT巡天望远镜（VST）ATLAS调查的一部分。这里提供的数据-完整调查的一个子集-均匀地覆盖了以星系为中心的25 ° 2的区域，在g，r和i波段。这种大面积的覆盖揭示了与以前对天炉座的研究的两个关键区别。首先，数据延伸超出标称潮汐半径的矮星突出了第二个不同的红巨星分支人口的存在。这个更蓝的红巨星分支似乎与水平分支种群是同时代的。第二，一个壳结构位于大约1英尺。从天炉座中心的.044被证明是一个错误识别的背景星系密度过高。最后一个结果进一步质疑了关于天炉座在相对较近的过去经历了一次富含气体的合并的假设。
We present a panoramic study of the Fornax dwarf spheroidal galaxy, using data obtained as part of the VLT Survey Telescope (VST) ATLAS Survey. The data presented here – a subset of the full survey – uniformly cover a region of 25 deg2 centred on the galaxy, in g, r and i bands. This large area coverage reveals two key differences to previous studies of Fornax. First, data extending beyond the nominal tidal radius of the dwarf highlight the presence of a second distinct red giant branch population. This bluer red giant branch appears to be co-eval with the horizontal branch population. Secondly, a shell structure located approximately 1 ∘ . .∘ 4 from the centre of Fornax is shown to be a mis-identified background overdensity of galaxies. This last result casts further doubt on the hypothesis that Fornax underwent a gas-rich merger in its relatively recent past.