论文标题

传奇调查。 ii。在类似银河系的星系周围建立卫星系统的统计样本

The SAGA Survey. II. Building a Statistical Sample of Satellite Systems around Milky Way-like Galaxies

论文作者

Mao, Yao-Yuan, Geha, Marla, Wechsler, Risa H., Weiner, Benjamin, Tollerud, Erik J., Nadler, Ethan O., Kallivayalil, Nitya

论文摘要

我们介绍了围绕银河类似物(SAGA)调查的正在进行的卫星的第二阶段结果。完成后,传奇调查将在光谱上识别卫星星系比$ m_ {r,o} = -12.3 $左右100米米(MW)的类似物(MW)$ z \ sim 0.01 $。在第二阶段中,我们已经超过了I阶段I的样本量超过三倍,从而提供了127个卫星约36兆瓦类似物的结果,具有改进的目标选择策略和深度的光度成像目录,来自黑暗能源调查和传统调查。我们获得了25,372个星系红移,达到$ z = 0.2 $的峰值。这些数据显着增加了非常低的红移对象的光谱覆盖范围,$ 17 <r_o <20.75 $ awers of Saga主机周围的主机,创建了一个唯一的数据集,该数据集将本地组置于更广泛的上下文中。每个系统的确认卫星数量从零到九个,与宿主星系和最明亮的卫星发光相关。我们发现,MW卫星的数量和亮度与从与SAGA系统相同的基本分布中绘制而成。大多数已确认的传奇卫星是恒星形成,随着卫星恒星质量和宿主星系减小的半径降低,淬灭的分数增加。总体而言,卫星在传奇系统中淬灭的分数低于本地组。我们比较基于冷暗物质模拟和经验银河系连接模型的理论预测的光度函数和径向分布,并发现结果广泛一致。

We present the Stage II results from the ongoing Satellites Around Galactic Analogs (SAGA) Survey. Upon completion, the SAGA Survey will spectroscopically identify satellite galaxies brighter than $ M_{r,o} = -12.3 $ around 100 Milky Way (MW) analogs at $ z \sim 0.01 $. In Stage II, we have more than quadrupled the sample size of Stage I, delivering results from 127 satellites around 36 MW analogs with an improved target selection strategy and deep photometric imaging catalogs from the Dark Energy Survey and the Legacy Surveys. We have obtained 25,372 galaxy redshifts, peaking around $ z = 0.2 $. These data significantly increase spectroscopic coverage for very low redshift objects in $ 17 < r_o < 20.75 $ around SAGA hosts, creating a unique data set that places the Local Group in a wider context. The number of confirmed satellites per system ranges from zero to nine, and correlates with host galaxy and brightest satellite luminosities. We find that the number and the luminosities of MW satellites are consistent with being drawn from the same underlying distribution as SAGA systems. The majority of confirmed SAGA satellites are star forming, and the quenched fraction increases as satellite stellar mass and projected radius from the host galaxy decrease. Overall, the satellite quenched fraction among SAGA systems is lower than that in the Local Group. We compare the luminosity functions and radial distributions of SAGA satellites with theoretical predictions based on cold dark matter simulations and an empirical galaxy-halo connection model and find that the results are broadly in agreement.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源