The continuity equation is developed for the stellar mass content of galaxies, and exploited to derive the stellar mass function of active and quiescent galaxies over the redshift range $z\sim 0-8$. The continuity equation requires two specific inputs gauged on observations: (i) the star formation rate functions determined on the basis of the latest UV+far-IR/sub-mm/radio measurements; (ii) average star-formation histories for individual galaxies, with different prescriptions for discs and spheroids. The continuity equation also includes a source term taking into account (dry) mergers, based on recent numerical simulations and consistent with observations. The stellar mass function derived from the continuity equation is coupled with the halo mass function and with the SFR functions to derive the star formation efficiency and the main sequence of star-forming galaxies via the abundance matching technique. A remarkable agreement of the resulting stellar mass function for active and quiescent galaxies, of the galaxy main sequence and of the star-formation efficiency with current observations is found; the comparison with data also allows to robustly constrain the characteristic timescales for star formation and quiescence of massive galaxies, the star formation history of their progenitors, and the amount of stellar mass added by in-situ star formation vs. that contributed by external merger events. The continuity equation is shown to yield quantitative outcomes that must be complied by detailed physical models, that can provide a basis to improve the (sub-grid) physical recipes implemented in theoretical approaches and numerical simulations, and that can offer a benchmark for forecasts on future observations with multi-band coverage, as it will become routinely achievable in the era of JWST.
More connected, more active: galaxy clusters and groups at z~1 and the connection between their quiescent galaxy fractions and large-scale environments
高红移的星系团,不同于本地的星系团,显示出多样的恒星形成活动。然而,目前还不清楚是什么使一些高红移星团在恒星形成中保持活跃。为了解决这个问题,我们进行了多目标光谱(MOS)观测的226高红移(0.8 < z < 1.3)星系的星系团候选人及其周围地区。我们的光谱观察揭示了在z ~ 0.9和z ~ 1.3处的六至八个簇/群。红移的测量表明我们的光度红移测量的可靠性,这反过来又给出了可信度使用光度红移成员的分析大尺度结构(LSSs)。我们对每个星系团周围的大尺度环境(~10 Mpc)的调查揭示了LSS-高达~10 Mpc尺度的结构-围绕着许多,但不是全部,已确认的超密度和星系团候选者。我们研究了星系过密度中静止星系部分与其周围LSS之间的相关性,样本量更大,约为20个过密度,包括在0.6 < z < 0.9处通过光度测量选择的过密度。有趣的是,嵌入这些扩展的LSS中的星系过密度显示出比类似红移的孤立星系更低的静止星系比例(~ 20%)(静止星系比例为~ 50%)。此外,我们发现一个可能的迹象表明,集群/集团具有较高的静止星系分数更集中。基于这些结果,我们认为,LSS的主要水库的气体和恒星形成的星系,以保持星系团新鲜和扩大的大小在z ~ 1。
The eROSITA Final Equatorial Depth Survey (eFEDS): X-ray emission around star-forming and quiescent galaxies at $0.05<z<0.3$
我们的目标是在一个大样本的星系的环银河系介质的热相的特征。我们堆叠X射线事件从SRG/eROSITA eFEDS调查周围的中央星系在GAMA 9小时领域,以构建径向投影软X射线光度分布作为其恒星质量和特定的恒星形成率的函数。我们考虑恒星质量范围为$2\times 10^{10}$-$10^{12}$ M $_\odot$($3\times 10^9$ -$6\times10^{11}$ M $_\odot$)的静止(恒星形成)星系的样本。对于静止的星系,X射线轮廓明显地扩展到整个可用的质量范围;然而,由于投影效应,测量的轮廓可能偏高,因为这些星系往往生活在稠密和炎热的环境中。对于质量最大的恒星形成样本($\geq10^{11}$ M $_\odot$),有一个延伸发射的检测提示。对于$< 10^{11}$ M $_\odot$的恒星形成星系的X射线叠加配置文件是兼容的未解决的来源,并符合预期的发射从微弱的活动星系核和X射线双星。首次测量了静止星系和恒星形成星系的平均X射线光度与恒星质量之间的平均关系。高质量($\geq 10^{11}$ M $_\odot$)恒星形成或静止星系遵循预期的维里化热晕的缩放,而低质量恒星形成星系显示出不太突出的光度和较弱的依赖于恒星质量,与弱活动星系核人口的经验模型一致。当比较我们的结果与国家的最先进的数值模拟,我们发现一个整体的一致性大($>80$ …
The Neutral Hydrogen Gas Content of Star-forming and Quiescent S0 Galaxies
Universiti Malaya(马来亚大学);Haverford College(哈弗福德学院);Space Telescope Science Institute(太空望远镜科学研究所);Johns Hopkins University(约翰斯·霍普金斯大学);National Centre for Particle Physics, Universiti Malaya(马来亚大学国家粒子物理中心)
The GOLIATH Survey: OVI Absorption Reveals CGM Evolution through the Starburst-to-Quiescent Transition in Massive Galaxies
North Carolina State University(北卡罗来纳州立大学);Space Telescope Science Institute(太空望远镜科学研究所);University of Notre Dame(圣母大学);University of Colorado(科罗拉多大学);New Mexico State University(新墨西哥州立大学);University of South Carolina(南卡罗来纳大学)
First detection of ultra-fast outflows in a quiescent galaxy
Institute of Space Sciences (ICE, CSIC)(空间科学研究所);Institut d’Estudis Espacials de Catalunya (IEEC)(加泰罗尼亚空间研究学院);Instituto de Astrofísica de Canarias (IAC)(加那利天体物理研究所);Universidad de La Laguna (ULL)(拉帕鲁纳大学);Yunnan Observatories, Chinese Academy of Sciences(中国科学院云南天文台);INAF - IASF Palermo(意大利国家天体物理研究所巴勒莫分所);The Catholic University of America(美利坚天主教大学);INAF, Osservatorio Astronomico di Brera(意大利国家天体物理研究所布拉耶天文台);Università degli Studi Roma Tre(罗马第三大学)
JWST Spectra Conclusively Show an Excess of Neutral Gas Outflows in Quiescent Galaxies at z=2-5
University of Washington(华盛顿大学);KAIST(韩国科学技术院);The University of Texas at Austin(德克萨斯大学奥斯汀分校);University of California, Santa Barbara(加州大学圣塔芭芭拉分校);Cosmic Dawn Center (DAWN)(宇宙黎明中心);University of Pittsburgh(匹兹堡大学)
Resolving the sub-parsec circumnuclear density profiles of quiescent galaxies: Evidence for Bondi accretion flows in tidal disruption event hosts
International Centre for Radio Astronomy Research – Curtin University(国际射电天文中心 - 科廷大学);School of Natural Sciences, Institute for Advanced Study(自然科学与高级研究院)