ANTLIA B: A FAINT DWARF GALAXY MEMBER OF THE NGC 3109 ASSOCIATION
ANTLIA B: A FAINT DWARF GALAXY MEMBER OF THE NGC 3109 ASSOCIATION
复制标题
ANTLIA B：NGC 3109 协会的一个暗矮星系成员
DOI：
10.1088/2041-8205/812/1/l13
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
C. Grillmair
中科院分区：
文献类型：
--
作者：
D. Sand;K. Spekkens;D. Crnojevi'c;J. Hargis;B. Willman;J. Strader;C. Grillmair
我们报告发现的Antlia B，一个暗淡的矮星系在距离NGC 3109（M V <$-15等？），位于本星系群边缘的NGC 3109矮星系团的主星系。红巨星分支的尖端到安特利亚B的距离为D = 1.29 ± 0.10 Mpc，这与到NGC 3109的距离一致。定性分析表明，新矮星的恒星群既有一个古老的、贫金属的红巨星分支（10 Gyr，？[Fe/H] θ −2），以及一个年龄在200-400百万年之间的年轻的蓝色种群，类似于最初的Antlia矮星，NGC 3109的另一个可能的卫星。Antlia B有H i气体，速度为v helio，H I？> = 376 km s−1，确认与NGC 3109（vhelio = 403 km s−1）的关联。Hi气体质量（MHi = 2.8 ± 0.2 × 105 M Ω？>）、恒星光度（MV = −9.7 ± 0.6等）和半光半径（rh = 273 ± 29 pc）都符合矮不规则星系和矮球状星系在局域体积中的性质，并且与狮子座P矮星系最为相似。Antlia B的发现是暗能量相机对NGC 3109的晕子结构和暗矮星伴星进行调查的初步结果，目的是将观测到的子结构与亚银河系区域的Λ+冷暗物质模型的预期进行比较。
We report the discovery of Antlia B, a faint dwarf galaxy at a projected distance of ∼72 kpc from NGC 3109 ( M V ∼ − 15 mag ?> ), the primary galaxy of the NGC 3109 dwarf association at the edge of the Local Group. The tip of the red giant branch distance to Antlia B is D = 1.29 ± 0.10 Mpc, which is consistent with the distance to NGC 3109. A qualitative analysis indicates the new dwarf's stellar population has both an old, metal-poor red giant branch ( ≳ 10 Gyr , ?> [Fe/H] ∼ −2), and a younger blue population with an age of ∼200–400 Myr, analogous to the original Antlia dwarf, another likely satellite of NGC 3109. Antlia B has H i gas at a velocity of v helio , H I ?> = 376 km s−1, confirming the association with NGC 3109 (vhelio = 403 km s−1). The H i gas mass (MH i = 2.8 ± 0.2 × 105 M ⊙ ?> ), stellar luminosity (MV = −9.7 ± 0.6 mag) and half light radius (rh = 273 ± 29 pc) are all consistent with the properties of dwarf irregular and dwarf spheroidal galaxies in the Local Volume, and is most similar to the Leo P dwarf galaxy. The discovery of Antlia B is the initial result from a Dark Energy Camera survey for halo substructure and faint dwarf companions to NGC 3109 with the goal of comparing observed substructure with expectations from the Λ+Cold Dark Matter model in the sub-Milky Way regime.
DOI：
10.1086/590336
发表时间：
2008-05
期刊：
The Astrophysical Journal
影响因子：
--
作者：
N. Martin;J. D. de Jong;H. Rix
通讯作者：
N. Martin;J. D. de Jong;H. Rix