We examine the star formation properties of bright (~0.1 L*) satellites around isolated ~L* hosts in the local Universe using spectroscopically confirmed systems in the Sloan Digital Sky Survey DR7. Our selection method is carefully designed with the aid of N-body simulations to avoid groups and clusters. We find that satellites are significantly more likely to be quenched than a stellar mass-matched sample of isolated galaxies. Remarkably, this quenching occurs only for satellites of hosts that are themselves quenched: while star formation is unaffected in the satellites of star-forming hosts, satellites around quiescent hosts are more than twice as likely to be quenched than stellar-mass matched field samples. One implication of this is that whatever shuts down star formation in isolated, passive L* galaxies also plays at least an indirect role in quenching star formation in their bright satellites. The previously-reported tendency for "galactic conformity" in color/morphology may be a by-product of this host-specific quenching dichotomy. The Sérsic indices of quenched satellites are statistically identical to those of field galaxies with the same specific star formation rates, suggesting that environmental and secular quenching give rise to the same morphological structure. By studying the distribution of pairwise velocities between the hosts and satellites, we find dynamical evidence that passive host galaxies reside in dark matter halos that are ~45% more massive than those of star-forming host galaxies of the same stellar mass. We emphasize that even around passive hosts, the mere fact that galaxies become satellites does not typically result in star formation quenching: we find that only ~30% of ~0.1 L* galaxies that fall in from the field are quenched around passive hosts, compared with ~0% around star forming hosts.
Mass and Environment as Drivers of Galaxy Evolution II: The quenching of satellite galaxies as the origin of environmental effects
我们将Peng等人（2010）对演化星系群的唯象研究扩展到Yang等人的SDSS群中的中心/卫星二分法。我们发现，卫星星系是负责所有的环境影响，在我们的早期工作。红色的中心部分并不取决于它们的环境，而只取决于它们的恒星质量，而卫星部分则取决于两者。我们定义了一个相对的卫星淬火效率，这是蓝色的中心，淬火后成为另一个星系的卫星的分数。这被证明是独立的恒星质量，但强烈依赖于当地的超密度。卫星的红色部分与局部过密度（一种测量群内位置的方法）的相关性要比与群的丰富度（即暗物质晕质量）的相关性好得多。这一点，以及卫星猝灭取决于局部密度而不是星系的恒星质量或晕质量的事实，为卫星猝灭过程的性质提供了线索。我们还表明，卫星星系的质量猝灭的行动也是独立的母晕DM质量。然后，我们应用Peng等人（2010）的方法来预测中心星系和卫星星系的质量函数，分裂为被动星系和主动星系，并表明这些与SDSS观测到的质量函数非常匹配，进一步加强了这种唯象方法的有效性。我们强调了这样一个事实，即恒星形成中心和卫星的观测M* 是相同的，恒星形成卫星的观测M* 与10^12 M \odot以上的晕质量无关，这强调了我们在Peng等人（2010）中确定的质量猝灭过程的普遍性。猝灭后的合并改变了中心星系的质量函数，但只能使典型中心星系的质量增加约25%。
ZENS IV. Similar Morphological Changes associated with Mass- and Environment-Quenching, and the Relative importance of Bulge Growth versus the Fading of Disks
Observations of environmental quenching in groups in the 11 Gyr since z=2.5: different quenching for central and satellite galaxies
我们提出了在红移范围0<z<2.5的星系群中恒星形成猝灭的直接观测证据。我们利用一个大样本的近6000组，选择固定的累积数密度从三个光度计目录，按照中央和卫星星系在大约11 Gyr的不断发展的静止分数。在z~0处，我们样本中的中心星系的恒星质量范围从银河系/M31类似物（M= 6.5 × 10^10 M \solar）到附近的大质量椭圆星系（M= 1.5 × 10^11 M \solar）。同一星系群中的卫星星系的质量低至大麦云（M= 6.5 × 10^9 M \solar）的两倍。使用统计背景减法，我们测量的平均静止帧颜色的星系在我们的集团和计算的演变静止分数的中心和卫星超过7个红移箱。我们的分析显示了明确的证据，恒星形成淬火组晕，与不同的淬火开始的中心和他们的卫星星系。利用我们中心星系的晕质量估计，我们发现当典型的晕质量达到10^12和10^13 M \solar之间时，恒星形成在中心关闭，这与晕淬灭模型的预测一致。相比之下，同一星系群中的卫星星系很可能会受到环境过程的影响而发生淬灭，其发生时间相对于它们的中央星系要延迟。虽然随着时间的推移，所有星系的恒星形成都受到抑制，但控制中心星系和卫星星系淬火的过程是不同的。虽然质量在决定中央星系的恒星形成活动方面起着重要作用，但卫星星系的猝灭主要取决于它们所处的环境。
The environment-dependent bimodality of the distribution of stellar mass ($M_\ast$) and specific star formation rate (sSFR) of galaxies, and its explanation in terms of the central-satellite dichotomy, form a cornerstone of our current understanding of galaxy evolution in the hierarchical structure formation paradigm. We revisit this framework in the IllustrisTNG simulation in the context of the most extreme local tidal anisotropy $α_{\rm peak}$ experienced by each galaxy over cosmic time, which is an excellent proxy for environmental influence. We show that, while sharing a common monotonic $…
Spatial segregation as the origin of anisotropic satellite quenching in haloes and beyond
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；College of Astronomy and Space Sciences, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Universidad Autónoma de Madrid（马德里自治大学）；Centro de Investigación Avanzada en Física Fundamental (CIAFF), Universidad Autónoma de Madrid（马德里自治大学基础物理前沿研究中心）；Institute for Astronomy, University of Edinburgh（爱丁堡大学天体物理研究所）；Department of Physics and Astronomy, University of the Western Cape（西开普大学物理与天文学系）
We quantify the relative importance of environmental quenching versus pre-processing in $z\sim1$ clusters by analysing the infalling galaxy population in the outskirts of 15 galaxy clusters at $0.8<z<1.4$ drawn from the GOGREEN and GCLASS surveys. We find significant differences between the infalling galaxies and a control sample; in particular, an excess of massive quiescent galaxies in the infalling region. These massive infalling galaxies likely reside in larger dark matter haloes than similar-mass control galaxies because they have twice as many satellite galaxies. Furthermore, these satel…
The vast majority of low-mass satellite galaxies around the Milky Way and M31 appear virtually devoid of cool gas and show no signs of recent or ongoing star formation. Cosmological simulations demonstrate that such quenching is expected and is due to the harsh environmental conditions that satellites face when joining the Local Group (LG). However, recent observations of Milky Way analogues in the SAGA survey present a very different picture, showing the majority of observed satellites to be actively forming stars, calling into question the realism of current simulations and the typicality of…
We investigate how star formation quenching proceeds within central and satellite galaxies using spatially resolved spectroscopy from the SDSS-IV MaNGA DR15. We adopt a complete sample of star formation rate surface densities ($Σ_{\rm SFR}$), derived in Bluck et al. (2020), to compute the distance at which each spaxel resides from the resolved star forming main sequence ($Σ_{\rm SFR} - Σ_*$ relation): $ΔΣ_{\rm SFR}$. We study galaxy radial profiles in $ΔΣ_{\rm SFR}$, and luminosity weighted stellar age (${\rm Age_L}$), split by a variety of intrinsic and environmental parameters. Via several s…
The impact of galactic properties and environment on the quenching of central and satellite galaxies: A comparison between SDSS, Illustris and L-Galaxies
我们量化的影响，各种银河系和环境的属性淬火的恒星形成。我们整理了斯隆数字巡天数据第7版（SDSS DR 7）中的$\sim$ 40万个中央星系和$\sim$ 10万个卫星星系的样本。具体地说，我们考虑了中心速度色散（$σ_{c}$），恒星，晕，球和盘质量，局部密度，球对总的比率，集团中心距离和星系晕质量比。我们开发和应用一种新的统计技术来量化的淬火分数（$f_{\rm Quench}$）的变化的一个参数的影响，而保持其余的参数固定。对于中心，我们发现，$f_{\rm Quench} - σ_{c}$的关系是紧密和陡峭的比任何其他变量考虑。我们比较的Illustris流体动力学模拟和慕尼黑半解析模型（L-Galerkin），发现我们的结果中心是定性一致的淬火通过无线电模式活动星系核反馈的预测，暗示在这个过程中的可行性，解释我们的观测趋势。然而，我们也发现的证据表明，淬火在L-半乳糖苷是太有效，淬火在插图不够有效，相比观察。对于卫星，我们发现强有力的证据表明，环境影响其淬火分数在固定的中心速度分散，特别是在较低的质量。在更高的质量，卫星的行为完全相同的中心，在他们的淬火。在考虑的环境参数中，在固定的中心速度色散下，局部密度对卫星猝灭分数的影响最大。
Observations suggest that satellite quenching plays a major role in the build-up of passive, low-mass galaxies at late cosmic times. Studies of low-mass satellites, however, are limited by the ability to robustly characterize the local environment and star-formation activity of faint systems. In an effort to overcome the limitations of existing data sets, we utilize deep photometry in Stripe 82 of the Sloan Digital Sky Survey, in conjunction with a neural network classification scheme, to study the suppression of star formation in low-mass satellite galaxies in the local Universe. Using a stat…
A recent observational result finds that the quenching of satellites in groups at $z=0.08$ has an angular dependence relative to the semi-major axis of the central galaxy. This observation is described as `anisotropic quenching' or `angular conformity'. In this paper I study the variation in the colour of a mass limited sample of satellite galaxies relative to their angle from the major axis of the Brightest Cluster Galaxy in the CLASH clusters up to $z\sim0.5$, 4 Gyr further in lookback time. The same result is found: galaxies close to the major axis are more quenched than those along the min…
Galaxy evolution in groups and clusters: star formation rates, red sequence fractions, and the persistent bimodality
利用斯隆数字巡天数据发布7创建的星系群/星系团目录，我们详细研究了卫星星系的特定恒星形成率（SSFR）分布及其对恒星质量，宿主晕质量和晕中心半径的依赖性。所有星系，无论是中央卫星星系还是中央卫星星系，都表现出类似的双峰SSFR分布，在SSFR约10^-11 yr^-1处有一个强烈的突变，SSFR峰值也同样高;在“绿谷”中，没有一个星系会过多。卫星星系更有可能位于SSFR分布的淬灭（“红色序列”）一侧。此外，卫星淬火分数超过场星系值几乎是独立的星系恒星质量。在晕质量低至3 x 10^11 Msol的星系团中，卫星的淬灭率会持续增强，并随着晕质量的增加而显著增加，而且越靠近晕中心，淬灭率越高。我们发现，一旦这些星系已被分解成中心和卫星的大质量星系团周围的~2R_vir以外的星系没有可检测的淬火增强。这些趋势意味着：（1）星系在穿越到更大质量的主晕~R_vir内之前，不会经历明显的环境效应;（2）在此之后，活动卫星星系中的恒星形成继续以与活动中心星系相同的方式演化数个Gyr;（3）一旦开始，卫星恒星形成猝灭迅速发生。这些结果对卫星特定的猝灭机制有很强的约束，我们将在配套论文中进一步讨论。
Galaxy formation in the Planck cosmology - IV. Mass and environmental quenching, conformity and clustering
我们在Henriques et al.（2015）的星系形成模拟中研究了恒星形成的猝灭随红移、环境和恒星质量的变化，该模拟在两个千禧年模拟中实现了慕尼黑半解析模型（L-GALAXIES）的更新版本，并将其扩展到普朗克宇宙学。在这个模型中，大质量星系被活动星系核的反馈淬灭，这取决于黑洞和热气体的质量，因此间接地取决于恒星的质量。此外，任何质量的卫星星系都可以通过气体的冲压压力或潮汐剥离以及通过抑制气体流入而熄灭。这种组合的过程产生淬火效率，这取决于恒星质量，主机晕质量，环境密度，距离组中心和组中心星系性质的方式同意定性与观察。一些差异仍然存在于密集的区域和靠近群体中心的地方，那里的淬火似乎仍然太有效。此外，虽然大质量星系的平均恒星年龄与观测结果一致，但假设的活动星系核反馈模型允许在后期有太多的恒星形成。活动星系核的反馈和环境效应在密度较高的环境中更强，这一事实导致了中心星系和卫星星系的淬灭之间的相关性，这大致再现了晕内观察到的一致性趋势。
We present the cumulative star-formation histories (SFHs) of >15000 dwarf galaxies ($M_{*}=10^{7-10}M_{\odot}$) from the TNG50 run of the IllustrisTNG suite across a vast range of environments. The key factors determining the dwarfs' SFHs are their status as central or satellite and their stellar mass, with centrals and more massive dwarfs assembling their stellar mass at later times on average compared to satellites and lower mass dwarfs. The satellites (in hosts of total mass $M_{200c,\,host}=10^{12-14.3}M_{\odot}$) assembled 90% of their z=0 stellar mass ~$7.0_{-5.5}^{+3.3}$ Gyr ago, while …
(Abridged) We explored 18 clusters from LoCuSS at z~0.2 with ACReS spectra of ~1800 cluster members at R<R200 in a mass-complete sample. The metallicities of SF cluster galaxies with R<R200 were found to be enhanced with respect to the MZR of coeval field SF galaxies. This metallicity enhancement is limited to lower-mass satellites of the 9 clusters with a passive BCG. Many of the SF galaxies with enhanced metallicities are found in the core regions of the phase-space diagram expected for virialized populations. We find a higher fraction of higher mass SF galaxies at R<R500 in clusters with ac…
ISCEA (Infrared Satellite for Cosmic Evolution Astrophysics) is a small astrophysics mission whose Science Goal is to discover how galaxies evolved in the cosmic web of dark matter at cosmic noon. Its Science Objective is to determine the history of star formation and its quenching in galaxies as a function of local density and stellar mass when the Universe was 3-5 Gyrs old (1.2<z<2.1). ISCEA is designed to test the Science Hypothesis that during the period of cosmic noon, at 1.7 < z < 2.1, environmental quenching is the dominant quenching mechanism for typical galaxies not only in clusters a…
We use the IllustrisTNG simulations to show how the fractions of quenched galaxies vary across different environments and cosmic time, and to quantify the role AGN feedback and preprocessing play in quenching group and cluster satellites. At $z=0$, we select galaxies with $M_* = 10^{9-12} M_{\odot}$ residing within ($\leq R_{200c}$) groups and clusters of total host mass $M_{200c}=10^{13-15.2} M_{\odot}$. TNG predicts a quenched fraction of $\sim70-90\%$ (on average) for centrals and satellites $\gtrsim 10^{10.5} M_{\odot}$, regardless of host mass, cosmic time ($0\leq z\leq0.5$), clustercentr…
This work uses multiscale environments and structures of galaxies in the Sloan Digital Sky Survey as consistency checks of the evolution from starburst to quiescence at redshift $z < 0.2$. The environmental indicators include fixed aperture mass overdensities ($δ_{x\mathrm{Mpc}}$, $x \in \{0.5, 1, 2, 4, 8\}\,h^{-1}$Mpc), $k$-nearest neighbor distances, the tidal parameter, halo mass ($M_h$), and satellite/central classification. The residuals of specific star formation rates ($Δ\,\mathrm{SSFR}$) is used to select starbursts ($Δ\,\mathrm{SSFR} > 0.6\,$dex, $N \approx 8,\,600$). Quenched post-st…
We investigate how large-scale cosmic filaments impact the quenching of galaxies within one virial radius of 324 simulated clusters from The Three Hundred project. We track cosmic filaments with the versatile, observation-friendly program DisPerSE and identify halos hosting galaxies with VELOCIRaptor. We find that cluster galaxies close to filaments tend to be more star-forming, bluer, and contain more cold gas than their counterparts further away from filaments. This effect is recovered at all stellar masses. This is in stark contrast with galaxies residing outside of clusters, where galaxies…
