In this paper we present a simple color-magnitude selection and obtain a large sample of 33,893 massive quiescent galaxies at intermediate redshifts (1<z<1.5). We choose the longest wavelength available in the Hyper-Supreme-Cam (HSC) deep survey, the Y band and i-Y color, to select the 4000A Balmer jump in passive galaxies to the highest redshift possible within the survey. With the rich multi-wavelength data in the HSC deep fields, we then confirm that the selected galaxies are in the targeted redshift range of 1<z<1.5, lie in the passive region of the UVJ diagram, and have high stellar masses at log(M*/M_sun)>10.5, with a median of log(M*/M_sun)=11.0. A small fraction of our galaxies is also covered by the HST CANDELS. Morphological analysis in the observed H band shows that the majority of this subsample are early-type galaxies. As massive early-type galaxies trace the high density regions in the large scale structure in the universe, our study provides a quick and simple way to obtain a statistical significant sample of massive galaxies in a relative narrow redshift range. Our sample is 7-20 times larger at the massive end (log(M*/M_sun)>10.5) than any existing samples obtained in previous surveys. This is a pioneer study, and the technique introduced here can be applied to future wide-field survey to study large scale structure, and to identify high density region and clusters.
Massive quiescent galaxies at high redshift can shed light on the processes of galaxy mass assembly and quenching of the star formation at early epochs. We present observer-frame color-color diagrams designed to identify candidate quiescent galaxies from z=2.5 up to the highest redshifts, that can be then be selected for spectroscopic follow-up observations. The application to the COSMOS2015 catalog shows that, after refining the selection with SED fitting, the number of massive old quiescent galaxies exceeds the forecast of state-of-the-art semi-analytic models, pointing out the need of an im…
We use Hectospec mounted on the 6.5-meter MMT to carry out a redshift survey of red ($r-i>0.2$, $g-r>0.8$, $r<21.3$) galaxies in the COSMOS field to measure the environments of massive compact quiescent galaxies at intermediate redshift. The $>90\%$ complete magnitude limited survey includes redshifts for 1766 red galaxies with $r < 20.8$ covering the central square degree of the field; $65\%$ of the redshifts in this sample are new. We select a complete magnitude limited quiescent sample based on the rest-frame $UVJ$ colors. When the density distribution is sampled on a scale of 2 Mpc massive…
We examine the Fundamental Plane (FP) and mass-to-light ratio ($M/L$) scaling relations using the largest sample of massive quiescent galaxies at $1.5<z<2.5$ to date. The FP ($r_{e}, σ_{e}, I_{e}$) is established using $19$ $UVJ$ quiescent galaxies from COSMOS with $Hubble$ $Space$ $Telescope$ $(HST)$ $H_{F160W}$ rest-frame optical sizes and X-shooter absorption line measured stellar velocity dispersions. For a very massive, ${\rm{log}}(M_{\ast}/M_{\odot})>11.26$, subset of 8 quiescent galaxies at $z>2$, from Stockmann et al. (2020), we show that they cannot passively evolve to the local Coma …
We search the Sloan Digital Sky Survey and the Baryon Oscillation Sky Survey to identify ~5500 massive compact quiescent galaxy candidates at 0.2<z<0.8. We robustly classify a subsample of 438 E+A galaxies based on their spectral properties and make this catalog publicly available. We examine sizes, stellar population ages and kinematics of galaxies in the sample and show that the physical properties of compact E+A galaxies suggest that they are a progenitor of massive compact quiescent galaxies. Thus, two classes of objects-compact E+A and compact quiescent galaxies-may be linked by a common …
High-redshift galaxy clusters, unlike local counterparts, show diverse star formation activities. However, it is still unclear what keeps some of the high-redshift clusters active in star formation. To address this issue, we performed a multi-object spectroscopic (MOS) observation of 226 high-redshift (0.8 < z < 1.3) galaxies in galaxy cluster candidates and the areas surrounding them. Our spectroscopic observation reveals six to eight clusters/groups at z ~ 0.9 and z ~ 1.3. The redshift measurements demonstrate the reliability of our photometric redshift measurements, which in turn gives cred…
The massive galaxy population above the characteristic Schechter mass M*~10^10.6 Msun contributes to about half of the total stellar mass in the local Universe. These massive galaxies usually reside in hot dark matter haloes above the critical shock-heating mass ~10^12 Msun, where the external cold gas supply to these galaxies is expected to be suppressed. When galaxies run out of their cold gas reservoir, they become dead and quiescent. Therefore, massive quiescent galaxies living in hot haloes are commonly believed to be gas-poor. Based on the data from SDSS, ALFALFA, GASS and COLD GASS surv…
We report the discovery of eMACSJ1341-QG-1, a quiescent galaxy at $z=1.594$ located behind the massive galaxy cluster eMACSJ1341.9$-$2442 ($z=0.835$). The system was identified as a gravitationally lensed triple image in Hubble Space Telescope images obtained as part of a snapshot survey of the most X-ray luminous galaxy clusters at $z>0.5$ and spectroscopically confirmed in ground-based follow-up observations with the ESO/X-Shooter spectrograph. From the constraints provided by the triple image, we derive a first, crude model of the mass distribution of the cluster lens, which predicts a grav…
We explore the relations between size, stellar mass and average stellar population age (indicated by D$_n4000$ indices) for a sample of $\sim11000$ intermediate-redshift galaxies from the SHELS spectroscopic survey (Geller et al. 2014) augmented by high-resolution Subaru Telescope Hyper Suprime-Cam imaging. In the redshift interval $0.1<z<0.6$, star forming galaxies are on average larger than their quiescent counterparts. The mass-complete sample of $\sim3500$ $M_*>10^{10}\, M_\odot$ quiescent galaxies shows that the average size of a $10^{11}\, M_\odot$ quiescent galaxy increases by $\lesssim…
We investigate the growth of massive quiescent galaxies at $z<0.6$ based on the Sloan Digital Sky Survey and the Smithsonian Hectospec Lensing Survey---two magnitude limited spectroscopic surveys of high data quality and completeness. Our three parameter model links quiescent galaxies across cosmic time by self-consistently evolving stellar mass, stellar population age sensitive $D_n4000$ index, half-light radius and stellar velocity dispersion. Stellar velocity dispersion is a robust proxy of dark matter halo mass; we use it to connect galaxies and dark matter halos and thus empirically const…
We present the relation between galaxy structure and spectral type, using a K-selected galaxy sample at 0.5<z<2.0. Based on similarities between the UV-to-NIR spectral energy distributions, we classify galaxies into 32 spectral types. The different types span a wide range in evolutionary phases, and thus -- in combination with available CANDELS/F160W imaging -- are ideal to study the structural evolution of galaxies. Effective radii (R_e) and Sersic parameters (n) have been measured for 572 individual galaxies, and for each type, we determine R_e at fixed stellar mass by correcting for the mas…
We report a massive quiescent galaxy at $z_{\rm spec}=3.0922^{+0.008}_{-0.004}$ spectroscopically confirmed at a protocluster in the SSA22 field by detecting the Balmer and Ca {\footnotesize II} absorption features with multi-object spectrometer for infrared exploration (MOSFIRE) on the Keck I telescope. This is the most distant quiescent galaxy confirmed in a protocluster to date. We fit the optical to mid-infrared photometry and spectrum simultaneously with spectral energy distribution (SED) models of parametric and nonparametric star formation histories (SFH). Both models fit the observed S…
We take advantage of the statistical power of the large-volume dark-matter-only Millennium simulation, combined with a sophisticated semi-analytic galaxy formation model, to explore whether the recently reported $z=3.7$ quiescent galaxy ZF-COSMOS-20115 (ZF; Glazebrook et al. 2017) can be accommodated in current galaxy formation models. In our model, a population of quiescent galaxies (QGs) with stellar masses and star formation rates comparable to those of ZF naturally emerges at redshifts $z<4$. There are two and five ZF analogues at the redshift $3.86$ and $3.58$ in the Millennium simulation…
We use high-resolution, multi-band imaging of ~16,500 galaxies in the CANDELS fields at 0 < z < 2.5 to study the evolution of color gradients and half-mass radii over cosmic time. We find that galaxy color gradients at fixed mass evolve rapidly between z~2.5 and z~1, but remain roughly constant below z~1. This result implies that the sizes of both star-forming and quiescent galaxies increase much more slowly than previous studies found using half-light radii. The half-mass radius evolution of quiescent galaxies is fully consistent with a model which uses observed minor merger rates to predict …
Where Giants Dwell: Probing the Environments of Early Massive Quiescent Galaxies
INAF - Astronomical Observatory of Trieste（意大利国家天体物理研究所的里雅斯特天文台）；IFPU - Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；Tianjin Normal University（天津师范大学）；Institute for Physics, Laboratory for Galaxy Evolution, EPFL（洛桑联邦理工学院星系演化实验室）
This Letter examines how the sizes, structures, and color gradients of galaxies change along the quiescent sequence. Our sample consists of ~400 quiescent galaxies at $1.0\le z\le2.5$ and $10.1 \le \log{M_*/M_\odot}\le11.6$ in three CANDELS fields. We exploit deep multi-band HST imaging to derive accurate mass profiles and color gradients, then use an empirical calibration from rest-frame UVJ colors to estimate galaxy ages. We find that -- contrary to previous results -- the youngest quiescent galaxies are not significantly smaller than older quiescent galaxies at fixed stellar mass. These `po…
One key problem in astrophysics is understanding how and why galaxies switch off their star formation, building the quiescent population that we observe in the local Universe. From the GAMA and VIPERS surveys, we use spectroscopic indices to select quiescent and candidate transition galaxies. We identify potentially rapidly transitioning post-starburst galaxies, and slower transitioning green-valley galaxies. Over the last 8 Gyrs the quiescent population has grown more slowly in number density at high masses (M$_*>10^{11}$M$_\odot$) than at intermediate masses (M$_*>10^{10.6}$M$_\odot$). There…
Quiescent fractions in high-redshift galaxy groups reflect their hot-or-cold state of gas accretion
Université Paris-Saclay, CNRS, CEA（巴黎萨克雷大学，法国国家科学研究中心，法国原子能和替代能源委员会）；Instituto de Física, Pontificia Universidad Católica de Valparaíso（天主教瓦爾帕萊索大學物理研究所）；Cosmic Dawn Center (DAWN)（黎明宇宙中心）；DTU Space, Technical University of Denmark（丹麦技术大学空间研究所）
The cosmic noon (z~1.5-3) marked a period of vigorous star formation for most galaxies. However, about a third of the more massive galaxies at those times were quiescent in the sense that their observed stellar populations are inconsistent with rapid star formation. The reduced star formation activity is often attributed to gaseous outflows driven by feedback from supermassive black holes, but the impact of black hole feedback on galaxies in the young Universe is not yet definitively established. We analyze the origin of quiescent galaxies with the help of ultra-high resolution, cosmological s…
We investigate the effects of galaxy environment on the evolution of the quiescent fraction ($f_\mathrm{Q}$) from z =0.8 to 0.0 using spectroscopic redshifts and multi-wavelength imaging data from the PRIsm MUlti-object Survey (PRIMUS) and the Sloan Digitial Sky Survey (SDSS). Our stellar mass limited galaxy sample consists of ~14,000 PRIMUS galaxies within z = 0.2-0.8 and ~64,000 SDSS galaxies within z = 0.05-0.12. We classify the galaxies as quiescent or star-forming based on an evolving specific star formation cut, and as low or high density environments based on fixed cylindrical aperture …
We use surveys covering the redshift range $0.05 < z < 3.8$ to explore quiescent galaxy scaling relations and the redshift evolution of the velocity dispersion, size, and dynamical mass at fixed stellar mass. For redshift $z < 0.6$ we derive mass limited samples and demonstrate that these large samples enhance constraints on the evolution of the quiescent population. The constraints include 2985 new velocity dispersions from the SHELS F2 survey (Geller et al. 2014). In contrast with the known substantial evolution of size with redshift, evolution in the velocity dispersion is negligible. The d…
We investigate the median flattening of galaxies at $0.2<z<4.0$ in all five CANDELS/3D-HST fields via the apparent axis ratio $q$. We separate the sample into bins of redshift, stellar-mass, sérsic index, size, and UVJ determined star-forming state to discover the most important drivers of the median $q$ ($q_{med}$). Quiescent galaxies at $z<1$ and $M_{*}>10^{11}M_{\odot}$ are rounder than those at lower masses, consistent with the hypothesis that they have grown significantly through dry merging. The massive quiescent galaxies at higher redshift become flatter, and are as flat as star forming…
Measuring stellar velocity dispersions of quiescent galaxies beyond $z\sim2$ is observationally challenging. Such measurements require near-infrared spectra with a continuum detection of at least moderate signal-to-noise, often necessitating long integrations. In this paper, we present deep X-Shooter spectroscopy of one of only two known gravitationally-lensed massive quiescent galaxies at $z>2$. This galaxy is quadruply imaged, with the brightest images magnified by a factor of $\sim5$. The total exposure time of our data is 9.8 hours on-source; however the magnification, and the slit placeme…
We present a detailed analysis of a large sample of spectroscopically confirmed ultra-massive quiescent galaxies (${\rm{log}}(M_{\ast}/M_{\odot})\sim11.5$) at $z\gtrsim2$. This sample comprises 15 galaxies selected in the COSMOS and UDS fields by their bright K-band magnitudes and followed up with VLT/X-shooter spectroscopy and HST/WFC3 $H_{F160W}$ imaging. These observations allow us to unambiguously confirm their redshifts ascertain their quiescent nature and stellar ages, and to reliably assess their internal kinematics and effective radii. We find that these galaxies are compact, consisten…
We report a robust sample of 10 massive quiescent galaxies at redshift, $z > 3$, selected using the first data from the JWST CEERS programme. Three of these galaxies are at $4 < z < 5$, constituting the best evidence to date for quiescent galaxies significantly before $z=4$. These extreme galaxies have stellar masses in the range log$_{10}(M_*/$M$_\odot) = 10.1-11.1$, and formed the bulk of their mass around $z \simeq 10$, with two objects having star-formation histories that suggest they had already reached log$_{10}(M_*/$M$_\odot) > 10$ by $z\gtrsim8$. We report number densities for our samp…
Protoclusters of galaxies have been found in the last quarter century. However, most of them have been found through the overdensity of star-forming galaxies, and there had been no known structures identified by multiple spectroscopically confirmed quiescent galaxies at $z>2.5$. In this letter, we report the discovery of an overdense structure of massive quiescent galaxies with the spectroscopic redshift $z=2.77$ in the COSMOS field, QO-1000. We first photometrically identify this structure as a $4.2σ$ overdensity with 14 quiescent galaxies in $7\times4\ {\rm pMpc^2}$ from the COSMOS2020 catal…
Previous work has demonstrated that at a given stellar mass, quiescent galaxies are more strongly clustered than star-forming galaxies. The contribution to this signal from central, as opposed to satellite, galaxies is not known, which has strong implications for galaxy evolution models. To investigate the contribution from central galaxies, here we present measurements of the clustering of isolated primary (IP) galaxies, used as a proxy for central galaxies, at ${0.2<z<0.9}$ with data from the PRIMUS galaxy redshift survey. Using a sample of spectroscopic redshifts for $\sim60,000$ galaxies w…
Deep ALMA and HST observations reveal the presence of a quenched massive galaxy within the $z=2.91$ galaxy group RO-1001. With a mass-weighted stellar age of $1.6 \pm 0.4 \,$Gyr this galaxy is one of the oldest known at $z\sim3$, implying that most of its $10^{11}\rm \, M_{\odot}$ of stars were rapidly formed at $z>6$--8. This is a unique example of the predominantly passive evolution of a galaxy over at least $3<z<6$ following its high-redshift quenching and a smoking-gun event pointing to the early imprint of an age-environment relation. At the same time, being in a dense group environment w…
We present spectra of the most massive quiescent galaxy yet discovered at $z>3$, spectroscopically confirmed via the detection of Balmer absorption features in the $H-$ and $K-$bands of Keck/MOSFIRE. The spectra confirm a galaxy with no significant ongoing star formation, consistent with the lack of rest-frame UV flux and overall photometric spectral energy distribution. With a stellar mass of $3.1^{+0.1}_{-0.2} \times 10^{11} ~\rm{M}_\odot$ at $z = 3.493$, this galaxy is nearly three times more massive than the highest redshift spectroscopically confirmed absorption-line identified galaxy kno…
Observations have shown that the star-formation activity and the morphology of galaxies are closely related, but the underlying physical connection is not well understood. Using the TNG50 simulation, we explore the quenching and the morphological evolution of the 102 massive quiescent galaxies in the mass range of $10.5<\log(M_{\rm stellar}/M_{\odot})<11.5$ selected at $z=0$. The morphology of galaxies is quantified based on their kinematics, and we measure the quenching timescale of individual galaxies directly from star formation history. We show that galaxies tend to be quenched more rapidl…
We report the detection of an ionized gas outflow from an $X$-ray active galactic nucleus (AGN) hosted in a massive quiescent galaxy in a protocluster at $z=3.09$ (J221737.29+001823.4). It is a type-2 QSO with broad ($W_{80}>1000$ km s$^{-1}$) and strong ($\log (L_{\rm [OIII]}$ / erg s$^{-1})\approx43.4$) [O {\footnotesize III}]$λλ$4959,5007 emission lines detected by slit spectroscopy in three-position angles using Multi-Object Infra-Red Camera and Spectrograph (MOIRCS) on the Subaru telescope and the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck-I telescope. In th…
We report on the discovery of a z=1.58 mature cluster around the high-redshift radio galaxy 7C1753+6311, first identified in the Clusters Around Radio-Loud AGN survey. Two-thirds of the excess galaxies within the central 1Mpc lie on a red sequence with a colour that is consistent with an average formation redshift of zf~3. We show that 80+/-6% of the red sequence galaxies in the cluster core are quiescent, while the remaining 20% are red due to dusty star formation. We demonstrate that the cluster has an enhanced quiescent galaxy fraction that is three times that of the control field. We also …
We examine the relation between surface brightness, velocity dispersion and size$-$the fundamental plane$-$for quiescent galaxies at intermediate redshifts in the COSMOS field. The COSMOS sample consists of $\sim150$ massive quiescent galaxies with an average velocity dispersion $σ\sim 250$ km s$^{-1}$ and redshifts between $0.2<z<0.8$. More than half of the galaxies in the sample are compact. The COSMOS galaxies exhibit a tight relation ($\sim0.1$ dex scatter) between surface brightness, velocity dispersion and size. At a fixed combination of velocity dispersion and size, the COSMOS galaxies …
We present new observations of MRG-M2129, a quiescent galaxy at z = 2.15 with the Atacama Large Millimeter/submillimeter Array (ALMA). With the combination of the gravitational lensing effect by the foreground cluster and the angular resolution provided by ALMA, our data reveal 1.2 mm continuum emission at $\sim130$ pc angular resolution. Compact dust continuum is detected at 7.9 $σ$ in the target but displaced from its stellar peak position by $62 \pm 38$ mas, or $\sim169 \pm 105$ pc in the source plane. We find considerably high dust-to-stellar mass ratio, $4 \times 10^{-4}$. From non-detect…
Scaling relations between galaxy structures and dynamics have been studied extensively for early and late-type galaxies, both in the local universe and at high redshifts. The abundant differences between the properties of disky and elliptical, or star-forming and quiescent, galaxies seem to be characteristic of the local Universe; such clear distinctions begin to disintegrate as observations of massive galaxies probe higher redshifts. In this Paper, we investigate the existence the mass fundamental plane of all massive galaxies ($σ\gtrsim$ 100 km/s). This work includes local galaxies (0.05<z<0…
Massive compact systems at 0.2<z<0.6 are the missing link between the predominantly compact population of massive quiescent galaxies at high redshift and their analogs and relics in the local volume. The evolution in number density of these extreme objects over cosmic time is the crucial constraining factor for the models of massive galaxy assembly. We select a large sample of ~200 intermediate-redshift massive compacts from the BOSS spectroscopic dataset by identifying point-like SDSS photometric sources with spectroscopic signatures of evolved redshifted galaxies. A subset of our targets hav…
We present constraints on the dust continuum flux and inferred gas content of a gravitationally lensed massive quiescent galaxy at $z$=1.883$\pm$0.001 using AzTEC 1.1mm imaging with the Large Millimeter Telescope. MRG-S0851 appears to be a prototypical massive compact quiescent galaxy, but has evidence that it experienced a centrally concentrated rejuvenation event in the last 100 Myr (see Akhshik et al. 2020). This galaxy is undetected in the AzTEC image but we calculate an upper limit on the millimeter flux and use this to estimate the H$_2$ mass limit via an empirically calibrated relation …
We introduce the largest to date survey of massive quiescent galaxies at redshift z~1.6. With these data, which cover 27.6 deg^2, we can find significant numbers of very rare objects such as ultra-massive quiescent galaxies that populate the extreme massive end of the galaxy mass function, or dense environments that are likely to become present-day massive galaxy clusters. In this paper, the first in a series, we apply our gzK adaptation of the BzK technique to select our z~1.6 galaxy catalog and then study the quiescent galaxy stellar mass function with good statistics over M_stars ~ 10^10.2 …
Using stellar population synthesis models to infer star formation histories (SFHs), we analyse photometry and spectroscopy of a large sample of quiescent galaxies which are members of Sunyaev-Zel'dovich (SZ)-selected galaxy clusters across a wide range of redshifts. We calculate stellar masses and mass-weighted ages for 837 quiescent cluster members at 0.3 < z < 1.4 using rest-frame optical spectra and the Python-based Prospector framework, from 61 clusters in the SPT-GMOS Spectroscopic Survey (0.3 < z < 0.9) and 3 clusters in the SPT Hi-z cluster sample (1.25 < z < 1.4). We analyse spectra of…
COSMOS2025: A Machine Learning Census of Massive Quiescent Galaxies at $2.5 < \text{z} < 5$
Institute for Advanced Studies in Basic Sciences (IASBS)（基础科学高等研究所）；Universität Bonn（波恩大学）；Institute for Research in Fundamental Sciences (IPM)（伊朗基本科学研究中心）
Massive galaxies at higher redshifts ($\emph{z}$ $>$ 2) show different characteristics from their local counterparts: They are compact and most likely have a disk. In this study, we trace the evolution of local massive galaxies by performing a detailed morphological analysis, namely, fitting single Sérsic profiles and performing bulge+disk decompositions. We analyze $\sim$ 250 massive galaxies selected from all CANDELS fields (COSMOS, UDS, EGS, GOODS-South and GOODS-North). We confirm that both star-forming and quiescent galaxies increase their sizes significantly from $\emph{z}$ $\approx$ 2.5…
The LEGA-C galaxy survey: multiple quenching channels for quiescent galaxies at $z\sim1$
Université de Liège（列日大学）；Universiteit Gent（根特大学）；University of Pittsburgh（匹兹堡大学）；Max-Planck Institut für Astronomie（马克斯·普朗克天体物理研究所）；National Taiwan University（台湾大学）；National Center for Theoretical Sciences（国家理论科学中心）；University of Michigan（密歇根大学）；University of Cambridge（剑桥大学）
We study structural properties of spectroscopically confirmed massive quiescent galaxies at $z\approx 3$ with one of the first sizeable samples of such sources, made of ten $10.8<\log(M_{\star}/M_{\odot})<11.3$ galaxies at $2.4 < z < 3.2$ in the COSMOS field whose redshifts and quiescence are confirmed by HST grism spectroscopy. Although affected by a weak bias toward younger stellar populations, this sample is deemed to be largely representative of the majority of the most massive and thus intrinsically rarest quiescent sources at this cosmic time. We rely on targeted HST/WFC3 observations an…
In the early Universe finding massive galaxies that have stopped forming stars present an observational challenge as their rest-frame ultraviolet emission is negligible and they can only be reliably identified by extremely deep near-infrared surveys. These have revealed the presence of massive, quiescent early-type galaxies appearing in the universe as early as z$\sim$2, an epoch 3 Gyr after the Big Bang. Their age and formation processes have now been explained by an improved generation of galaxy formation models where they form rapidly at z$\sim$3-4, consistent with the typical masses and ag…
We explore the buildup of quiescent galaxies using a sample of 28,469 massive ($M_\star \ge 10^{11}$M$_\odot$) galaxies at redshifts $1.5<z<3.0$, drawn from a 17.5 deg$^2$ area (0.33 Gpc$^3$ comoving volume at these redshifts). This allows for a robust study of the quiescent fraction as a function of mass at $1.5<z<3.0$ with a sample $\sim$40 times larger at log($M_{\star}$/$\rm M_{\odot}$)$\ge11.5$ than previous studies. We derive the quiescent fraction using three methods: specific star-formation rate, distance from the main sequence, and UVJ color-color selection. All three methods give sim…
Winding Back the Clock: Recent Star Formation Histories of Massive Quiescent Galaxies Are Consistent With Their Rapid Number Density Evolution Since $\mathbf{z\sim7}$
University of Pittsburgh（匹兹堡大学）；Steward Observatory, University of Arizona（亚利桑那大学斯图尔德天文台）；NSF National Optical-Infrared Astronomy Research Laboratory（美国国家光学红外天文研究实验室）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；University of Massachusetts, Amherst（马萨诸塞大学阿默斯特分校）；Center for Astrophysics, Harvard & Smithsonian（哈佛-史密森天体物理中心）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）
PANORAMIC: The Dawn of Massive Quiescent Galaxies I. Number Density and Cosmic Variance from 1000 arcmin$^2$ NIRCam Imaging
University of Arizona（亚利桑那大学）；NSF–DOE Vera C. Rubin Observatory/NSF NOIRLab（美国国家科学基金会-能源部维拉·C·鲁宾天文台/美国国家光学红外天文研究实验室）；University of Geneva（日内瓦大学）；Princeton University（普林斯顿大学）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；University of Pittsburgh（匹兹堡大学）；University of Massachusetts, Amherst（马萨诸塞大学阿默斯特分校）；Cosmic DAWN Center, Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所宇宙黎明中心）
REQUIEM-2D (REsolving QUIEscent Magnified galaxies with 2D grism spectroscopy) is comprised of a sample of 8 massive ($\log M_*/M_\odot > 10.6$) strongly lensed quiescent galaxies at $z\sim2$. REQUIEM-2D combines the natural magnification from strong gravitational lensing with the high spatial-resolution grism spectroscopy of \emph{Hubble Space Telescope} through a spectrophotometric fit to study spatially resolved stellar populations. We show that quiescent galaxies in the REQUIEM-2D survey have diverse formation histories manifesting as a gradient in stellar ages, including examples of (1) a…
We present the first direct spectroscopic measurement of the stellar velocity dispersion function (VDF) for massive quiescent and star-forming galaxies at $0.6 < z \leq 1.0$. For this analysis we use individual measurements of stellar velocity dispersion from high-S/N spectra from the public Large Early Galaxy Astrophysics Census (LEGA-C) survey. We report a remarkable stability of the VDF for both quiescent and star-forming galaxies within this redshift range, though we note the presence of weak evolution in the number densities of star-forming galaxies. We compare both VDFs with previous dir…
We explore the H-alpha emission in the massive quiescent galaxies observed by the KMOS-3D survey at 0.7 < z < 2.7. The H-alpha line is robustly detected in 20 out of 120 UVJ-selected quiescent galaxies, and we classify the emission mechanism using the H-alpha line width and the [NII]/H-alpha line ratio. We find that AGN are likely to be responsible for the line emission in more than half of the cases. We also find robust evidence for star formation activity in nine quiescent galaxies, which we explore in detail. The H-alpha kinematics reveal rotating disks in five of the nine galaxies. The dus…
