The satellite population around luminous red galaxies in the 25 deg2 DESI Legacy Imaging Surveys Early Data Release
The satellite population around luminous red galaxies in the 25 deg2 DESI Legacy Imaging Surveys Early Data Release
复制标题
25°2 DESI 传统成像巡天早期数据发布中发光红色星系周围的卫星群
DOI：
10.1093/mnras/stad118
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发表时间：
2023
影响因子：
4.8
通讯作者：
Rudnick, Gregory
中科院分区：
文献类型：
--
作者：
Townsend, Melinda;Rudnick, Gregory
发光红色星系（LRG）是最大质量星系的代表，最初在斯隆数字巡天中被选为大尺度结构的良好示踪剂。它们以均匀古老的恒星群为主，恒星形成率低，形态早期，冷气体很少。尽管拥有古老的恒星种群和很少的原位恒星形成，但研究表明，自 z = 1 以来，它们的恒星质量一直在增长，这意味着它们主要通过卫星的吸积来增长。由于缺乏深度成像数据集，这张图片的测试受到了限制，这些数据集既覆盖了足够大的天空区域以容纳大量的 LRG，又足够深以探测微弱的卫星。我们使用 DESI 传统成像巡天的 25 deg2 早期数据发布 (EDR) 来描述 Z = 0.65 范围内 LRG 卫星星系群的特征。 DESI 传统成像巡天包括比 SDSS 更深 2-2.5 星等的网格成像，并且具有更好的图像质量。我们使用一种新的统计背景技术来识别 1823 个 LRG 周围 0.2 <z< 0.65 的假定卫星星系的过量种群。在三个红移和光度箱中，我们测量卫星星系的数量及其 r−z 颜色分布，直至达到至少比 L* 暗 3.6 倍的静止框架带光度限制。此外，我们开发了一种正向建模技术，并将其应用于限制每个红移和光度箱中卫星的平均数量。最后，我们使用这些估计来确定 LRG 中恒星质量增长到当地宇宙的量。
Luminous red galaxies, or LRGs, are representative of the most massive galaxies and were originally selected in the Sloan Digital Sky Survey as good tracers of large-scale structure. They are dominated by by uniformly old stellar populations, have low star formation rates, early type morphologies, and little cold gas. Despite having old stellar populations and littlein situstar formation, studies have shown that they have grown their stellar mass since z = 1, implying that they grow predominantly via the accretion of satellites. Tests of this picture have been limited because of the lack of deep imaging data sets that both covers a large enough area of the sky to contain substantial numbers of LRGs and that also is deep enough to detect faint satellites. We use the 25 deg2Early Data Release (EDR) of the DESI Legacy Imaging Surveys to characterize the satellite galaxy population of LRGs out to z = 0.65. The DESI Legacy Imaging Surveys are comprised ofgrzimaging to 2–2.5 mag deeper than SDSS and with better image quality. We use a new statistical background technique to identify excess populations of putative satellite galaxies around 1823 LRGs at 0.2 <z< 0.65. In three redshift and luminosity bins we measure the numbers of satellite galaxies and theirr−zcolour distribution down to rest-frameg-band luminosity limits at least 3.6 times fainter thanL*. In addition, we develop a forward modeling technique and apply it to constrain the mean number of satellites in each of our redshift and luminosity bins. Finally, we use these estimates to determine the amount of stellar mass growth in LRGs down to the local Universe.