Gas and dust in star-forming galaxies at the peak epoch of galaxy assembly are presently the topic of intense study, but little is known about the interstellar medium (ISM) of distant, passively evolving galaxies. We report on a deep 3 mm-band search with IRAM/PdBI for molecular (H$_2$) gas in a massive ($M_{\star}{\sim}6{\times}10^{11}M_{\odot}$) elliptical galaxy at z=1.4277, the first observation of this kind ever attempted. We place a 3$σ$ upper limit of 0.32 Jy km/s on the flux of the CO($J$=2$\rightarrow$1) line or $L'_{\rm CO}$$<$8.8$\times$10$^{9}$ K km/s pc$^2$, assuming a disk-like CO-morphology and a circular velocity scaling with the stellar velocity dispersion as in local early-type galaxies (ETGs). This translates to an H$_2$ mass of $<$3.9$\times$10$^{10}$($α_{\rm CO}$/4.4)$M_{\odot}$ or a gas fraction of $\lesssim$6% assuming a Salpeter initial mass function (IMF) and an ISM dominated by H$_2$, as observed in many local, high-mass ellipticals. This low value approaches that of local ETGs, suggesting that the low star formation activity in massive, high-z passive galaxies reflects a true dearth of gas and a lesser role for inhibitive mechanisms like morphological quenching.
Dust Heating by Low-mass Stars in Massive Galaxies at z<1
利用Hubble空间望远镜/Wide Field Camera 3的成像数据和多波长光度表，研究了CANDELS场中0.2<z<1.0处被动演化星系和恒星形成星系的尘埃温度。我们从这些星系的恒星质量和表面亮度分布估算了低质量恒星的恒星辐射场，并计算了它们的稳态尘埃温度。首先，我们使用赫歇尔室女星系团巡天的深远红外数据，使用附近的早型星系测试了我们的方法，并证实估计的尘埃温度与观测到的温度在不确定性范围内是一致的。然后我们将该方法应用于0.2<z<1.0的星系，发现大多数Mstar > 10^{10} Msun的被动演化星系都具有较高的尘埃温度（Tdust > 20 K），因此实验室实验预计在弥漫ISM中尘埃颗粒表面分子氢的形成效率很低。被动演化星系的比例强烈依赖于所有红移处的预期尘埃温度，并随着温度的增加而迅速增加。这些结果表明，大质量星系中低质量恒星对尘埃的加热对大质量星系被动演化的继续起着重要作用，因为缺乏氢分子对紫外辐射的屏蔽作用，阻止了气体冷却和新恒星的形成。
Cosmography via stellar archaeology of low-redshift early-type galaxies from SDSS
Scuola Internazionale Superiore di Studi Avanzati (SISSA)（高等国际研究学校）；Institute for Fundamental Physics of the Universe (IFPU)（宇宙基础物理研究所）；Universitat Heidelberg（海德堡大学）；University of Trento（特伦托大学）；IRA-INAF（国家天体物理研究所阿布鲁佐天文台）；INFN-Sezione di Trieste（意大利国家核物理研究所的里雅斯特分部）
Investigating quenching in Recently Quenched Elliptical galaxies with HI studies
University of Missouri-Kansas City（密苏里大学堪萨斯城分校）；Arecibo Observatory, NAIC（阿雷西博天文台，北美星际与电离层中心）；University of Minnesota, Twin Cities（明尼苏达大学双城分校）；National Centre for Radio Astrophysics, Tata Institute of Fundamental Research（国家射电天体物理中心，塔塔基础研究所）
AT2022zod: An Unusual Tidal Disruption Event in an Elliptical Galaxy at Redshift 0.11
International Centre for Radio Astronomy Research—Curtin University（国际射电天文中心——科廷大学）；Artificial Intelligence for Physics Laboratory (Lab-IA)（物理人工智能实验室）；Centre for Astrophysics Research, University of Hertfordshire（赫特福德大学天体物理学研究中心）；School of Physics, The University of Sydney（悉尼大学物理学院）；ARC Centre of Excellence for Dark Matter Particle Physics（ARC暗物质粒子物理卓越中心）；HUN-REN Research Centre for Astronomy and Earth Sciences, Konkoly Observatory（匈牙利研究与教育网络天文学与地球科学研究中心孔科利天文台）；University of Granada（格拉纳达大学）；Donald Bren School of Information and Computer Sciences, University of California, Irvine（加州大学尔湾分校唐纳德布伦信息与计算机科学学院）；Lab for Computing and Applied Mathematics, COPDT-INPE-MCTI（计算与应用数学实验室）；Department of Physics, University of Nevada, Reno（内华达大学里诺分校物理系）；Nevada Center for Astrophysics, University of Nevada, Las Vegas（内华达大学拉斯维加斯分校内华达天体物理学中心）；Department of Astronomy, University of Michigan（密歇根大学天文学系）；Department of Astrophysics and Planetary Science, Villanova University（维拉诺瓦大学天体物理学与行星科学系）
