The LBT satellites of Nearby Galaxies Survey (LBT-SONG): the satellite population of NGC 628
The LBT satellites of Nearby Galaxies Survey (LBT-SONG): the satellite population of NGC 628
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DOI：
10.1093/mnras/staa3246
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
A Bianca Davis;A. Nierenberg;A. Peter;C. Garling;J. Greco;C. Kochanek;D. Utomo;K. Casey;
中科院分区：
文献类型：
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作者：
A Bianca Davis;A. Nierenberg;A. Peter;C. Garling;J. Greco;C. Kochanek;D. Utomo;K. Casey;
我们提出了大型双筒望远镜卫星附近星系调查（LBT-SONG）的第一个卫星系统，该调查表征了大麦哲伦云与银河系质量，恒星形成星系在局部体积中的密切卫星群。在本文中，我们描述了我们的卫星发现和完整性测量方法，并将这一框架应用于NGC 628，一个孤立的星系，约为银河系恒星质量的1/4。我们提出了两个新的矮卫星星系候选者：NGC 628 dwA和dwB， $\text{M}_{\text{V}}$分别= $-12.2$和$-7.7$。NGC 628 dwA是一个经典的矮星系，而NGC 628 dwB是一个低光度星系，在再电离后似乎已经被熄灭了。完备性修正表明，这两颗卫星的存在与CDM预测一致。卫星的颜色表明，这些星系既没有活跃的恒星形成，也没有超微小矮星所特有的纯粹古老的恒星群。相反，与我们之前对NGC 4214系统的研究一致，它们显示出最近淬火的迹象，进一步表明环境淬火可以在改变卫星数量方面发挥作用，甚至对比银河系小的宿主也是如此。
We present the first satellite system of the Large Binocular Telescope Satellites Of Nearby Galaxies Survey (LBT-SONG), a survey to characterize the close satellite populations of Large Magellanic Cloud to Milky Way-mass, star-forming galaxies in the Local Volume. In this paper, we describe our satellite finding and completeness measurement methodology and apply this framework to NGC 628, an isolated galaxy with ~1/4 the stellar mass of the Milky Way. We present two new dwarf satellite galaxy candidates: NGC 628 dwA, and dwB with $\text{M}_{\text{V}}$ = $-12.2$ and $-7.7$, respectively. NGC 628 dwA is a classical dwarf while NGC 628 dwB is a low-luminosity galaxy that appears to have been quenched after reionization. Completeness corrections indicate that the presence of these two satellites is consistent with CDM predictions. The satellite colors indicate that the galaxies are neither actively star-forming nor do they have the purely ancient stellar populations characteristic of ultrafaint dwarfs. Instead, and consistent with our previous work on the NGC 4214 system, they show signs of recent quenching, further indicating that environmental quenching can play a role in modifying satellite populations even for hosts smaller than the Milky Way.