The KMOS Redshift One Spectroscopic Survey (KROSS): Dynamical properties, gas and dark matter fractions of typical z~1 star-forming galaxies
John P. Stott, A. M. Swinbank, Helen L. Johnson, Alfie Tiley, Georgios Magdis, Richard Bower, Andrew J. Bunker, Martin Bureau, Chris M. Harrison, Matt J. Jarvis… 展开作者
John P. Stott, A. M. Swinbank, Helen L. Johnson, Alfie Tiley, Georgios Magdis, Richard Bower, Andrew J. Bunker, Martin Bureau, Chris M. Harrison, Matt J. Jarvis, Ray Sharples, Ian Smail, David Sobral, Philip Best, Michele Cirasuolo
备注：
Accepted for publication in MNRAS. This version has been updated to include additional references. The paper includes details of novel sky-subtraction techniques for KMOS, appropriate for high-z emission line galaxies
The KMOS Redshift One Spectroscopic Survey (KROSS) is an ESO guaranteed time survey of 795 typical star-forming galaxies in the redshift range z=0.8-1.0 with the KMOS instrument on the VLT. In this paper we present resolved kinematics and star formation rates for 584 z~1 galaxies. This constitutes the largest near-infrared Integral Field Unit survey of galaxies at z~1 to date. We demonstrate the success of our selection criteria with 90% of our targets found to be Halpha emitters, of which 81% are spatially resolved. The fraction of the resolved KROSS sample with dynamics dominated by ordered rotation is found to be 83$\pm$5%. However, when compared with local samples these are turbulent discs with high gas to baryonic mass fractions, ~35%, and the majority are consistent with being marginally unstable (Toomre Q~1). There is no strong correlation between galaxy averaged velocity dispersion and the total star formation rate, suggesting that feedback from star formation is not the origin of the elevated turbulence. We postulate that it is the ubiquity of high (likely molecular) gas fractions and the associated gravitational instabilities that drive the elevated star-formation rates in these typical z~1 galaxies, leading to the ten-fold enhanced star-formation rate density. Finally, by comparing the gas masses obtained from inverting the star-formation law with the dynamical and stellar masses, we infer an average dark matter to total mass fraction within 2.2$r_e$ (9.5kpc) of 65$\pm$12%, in agreement with the results from hydrodynamic simulations of galaxy formation.
We analyse the velocity dispersion properties of 472 z~0.9 star-forming galaxies observed as part of the KMOS Redshift One Spectroscopic Survey (KROSS). The majority of this sample is rotationally dominated (83 +/- 5% with v_C/sigma_0 > 1) but also dynamically hot and highly turbulent. After correcting for beam smearing effects, the median intrinsic velocity dispersion for the final sample is sigma_0 = 43.2 +/- 0.8 km/s with a rotational velocity to dispersion ratio of v_C/sigma_0 = 2.6 +/- 0.1. To explore the relationship between velocity dispersion, stellar mass, star formation rate and reds…
We construct Tully-Fisher relations (TFRs), from large samples of galaxies with spatially-resolved H$α$ emission maps from the K-band Multi-Object Spectrograph (KMOS) Redshift One Spectroscopic Survey (KROSS) at $z\approx1$. We compare these to data from the Sydney-Australian-Astronomical-Observatory Multi-object Integral-Field Spectrograph (SAMI) Galaxy Survey at $z\approx0$. We stringently match the data quality of the latter to the former, and apply identical analysis methods and sub-sample selection criteria to both to conduct a direct comparison of the absolute $K$-band magnitude and stel…
We present the KMOS Galaxy Evolution Survey (KGES), a $K$-band Multi-Object Spectrograph (KMOS) study of the H$α$ and [NII] emission from 288 $K$ band-selected galaxies at $1.2 \lesssim z \lesssim 1.8$, with stellar masses in the range $\log_{10}(M_{*}/\rm{M}_{\odot})\approx$9-11.5. In this paper, we describe the survey design, present the sample, and discuss the key properties of the KGES galaxies. We combine KGES with appropriately matched samples at lower redshifts from the KMOS Redshift One Spectroscopic Survey (KROSS) and the SAMI Galaxy Survey. Accounting for the effects of sample select…
We present results from the KMOS Lens-Amplified Spectroscopic Survey (KLASS), an ESO Very Large Telescope (VLT) large program using gravitational lensing to study the spatially resolved kinematics of 44 star-forming galaxies at 0.6<z<2.3 with a stellar mass of 8.1<log(M$_\star$/M$_{\odot}$)<11.0. These galaxies are located behind six galaxy clusters selected from the HST Grism Lens-Amplified Survey from Space (GLASS). We find that the majority of the galaxies show a rotating disk, but most of the rotation-dominated galaxies only have a low $\upsilon_{rot}/σ_0$ ratio (median of $\upsilon_{rot}/…
Detections and non-detections of Lyman alpha (Ly$α$) emission from $z>6$ galaxies ($<1$ Gyr after the Big Bang) can be used to measure the timeline of cosmic reionization. Of key interest to measuring reionization's mid-stages, but also increasing observational challenge, are observations at z > 7, where Ly$α$ redshifts to near infra-red wavelengths. Here we present a search for z > 7.2 Ly$α$ emission in 53 intrinsically faint Lyman Break Galaxy candidates, gravitationally lensed by massive galaxy clusters, in the KMOS Lens-Amplified Spectroscopic Survey (KLASS). With integration times of ~7-1…
We present the completed KMOS$^\mathrm{3D}$ survey $-$ an integral field spectroscopic survey of 739, $\log(M_{\star}/M_{\odot})>9$, galaxies at $0.6<z<2.7$ using the K-band Multi Object Spectrograph (KMOS) at the Very Large Telescope (VLT). KMOS$^\mathrm{3D}$ provides a population-wide census of kinematics, star formation, outflows, and nebular gas conditions both on and off the star-forming galaxy main sequence through the spatially resolved and integrated properties of H$α$, [N II], and [S II] emission lines. We detect H$α$ emission for 91% of galaxies on the main sequence of star-formation…
Supernovae and their remnants provide energetic feedback to the ambient interstellar medium (ISM), which is often distributed in multiple gas phases. Among them, warm molecular hydrogen (H$_2$) often dominates the cooling of the shocked molecular ISM, which has been observed with the H$_2$ emission lines at near-infrared wavelengths. Such studies, however, were either limited in narrow filter imaging or sparsely sampled mid-infrared spectroscopic observations with relatively poor angular resolutions. Here we present near-infrared ($H$- and $K$-band) spectroscopic mosaic observations towards th…
The Carina Nebula harbors a large population of high-mass stars, including at least 75 O-type and Wolf-Rayet stars, but the current census is not complete since further high-mass stars may be hidden in or behind the dense dark clouds that pervade the association. With the aim of identifying optically obscured O- and early B-type stars in the Carina Nebula, we performed the first infrared spectroscopic study of stars in the optically obscured stellar cluster Tr 16-SE, located behind a dark dust lane south of eta Car. We used the integral-field spectrograph KMOS at the ESO VLT to obtain H- and K…
We present the $0.6<z<2.6$ evolution of the ionized gas velocity dispersion in 175 star-forming disk galaxies based on data from the full KMOS$^{\rm 3D}$ integral field spectroscopic survey. In a forward-modelling Bayesian framework including instrumental effects and beam-smearing, we fit simultaneously the observed galaxy velocity and velocity dispersion along the kinematic major axis to derive the intrinsic velocity dispersion $σ_0$. We find a reduction of the average intrinsic velocity dispersion of disk galaxies as a function of cosmic time, from $σ_0\sim45$ km s$^{-1}$ at $z\sim2.3$ to $σ…
We present a rest-frame UV-optical stacked spectrum representative of massive quiescent galaxies at $1.0<z<1.3$ with log$(M_*/\rm{M_\odot})>10.8$. The stack is constructed using VANDELS survey data, combined with new KMOS observations. We apply two independent full-spectral-fitting approaches, measuring a total metallicity, [Z/H]=$-0.13\pm0.08$ with Bagpipes, and [Z/H]=$0.04\pm0.14$ with Alf, a fall of $\sim0.2-0.3$ dex compared with the local Universe. We also measure an iron abundance, [Fe/H] =$-0.18\pm0.08$, a fall of $\sim0.15$ dex compared with the the local Universe. We measure the alpha…
We investigate the dark matter halos of 256 star-forming disc-like galaxies at $z\sim 1$ using the KMOS redshift one spectroscopic survey (KROSS). This sample covers the redshifts $0.6 \leq z \leq 1.04$, effective radii $0.69 \leq R_e [\mathrm{kpc}] \leq 7.76$, and total stellar masses $8.7 \leq log(M_{\mathrm{star}} \ [\mathrm{M_\odot}]) \leq 11.32$. We present a mass modelling approach to study the rotation curves of these galaxies, which allow us to dynamically calculate the physical properties associated with the baryons and the dark matter halo. For the former we assume a Freeman disc, wh…
We present a observational study of the dark matter fraction in 225 rotation supported star-forming galaxies at $z\approx 0.9$ having stellar mass range: $ 9.0 \leq log(M_* \ \mathrm{M_\odot}) \leq 11.0$ and star formation rate: $0.49 \leq log \left(SFR \ \mathrm{[M_{\odot}\ yr^{-1}]} \right) \leq 1.77$. This is a sub sample of KMOS redshift one spectroscopic survey (KROSS) previously studied by \citet{GS20}. The stellar masses ($M_*$) of these objects were previously estimated using mass-to-light ratios derived from fitting the spectral energy distribution of the galaxies. Star formation rate…
The Complete Calibration of the Colour-Redshift Relation survey (C3R2) is a spectroscopic effort involving ESO and Keck facilities designed to empirically calibrate the galaxy colour-redshift relation - P(z|C) to the Euclid depth (i_AB=24.5) and is intimately linked to upcoming Stage IV dark energy missions based on weak lensing cosmology. The aim is to build a spectroscopic calibration sample that is as representative as possible of the galaxies of the Euclid weak lensing sample. In order to minimise the number of spectroscopic observations to fill the gaps in current knowledge of the P(z|C),…
Context: The identification and characterisation of populations of young massive stars in (giant) HII regions provides important constraints on i) the formation process of massive stars and their early feedback on the environment, and ii) the initial conditions for population synthesis models predicting the evolution of ensembles of stars. Aims: We identify and characterise the stellar populations of the following young giant HII regions: M8, G333.6-0.2, and NGC6357. Methods: We acquired H- and K-band spectra of around 200 stars using The K-band KMOS on the ESO Very Large Telescope. The target…
A Newly Discovered VVVX Star Cluster Surfing the Galactic Disk
ESO - European Southern Observatory（欧洲南方天文台）；Universidad Bernardo O’Higgins（贝尔纳多·奥希金斯大学）；Universidad Andres Bello（安德烈斯·贝略大学）；Vatican Observatory（梵蒂冈天文台）；Universidade Federal de Santa Catarina（圣卡塔琳娜联邦大学）；Universidad de Antofagasta（安托法加斯塔大学）；Universidade de Sao Paulo, IAG（圣保罗大学天体物理学和地球物理学院）
We investigate the shape of the Rotation Curves (RCs) of $z\sim 1$ star-forming galaxies and compare them with the local star-forming galaxies. For this purpose, we have used $409$ galaxies from the K-band Multi-Object Spectrograph (KMOS) for Redshift One Spectroscopic Survey (KROSS). This sample covers the redshift range $0.57\leq z \leq 1.04$, effective radii $0.69 \leq R_e \left[kpc \right] \leq 7.73$, absolute H-band magnitude $-24.46 \leq M_H \leq -18.85$ with median stellar mass $log\left(M_* \ \left[M_\odot \right]\right)=9.95$ and median total star-formation rate $log\left(SFR_{tot} \ …
In the central few degrees of the bulge of the Milky Way there is a flattened structure of gas, dust and stars (the central molecular zone) similar to nuclear disks in other galaxies. Due to extreme foreground extinction we possess only sparse information about the (mostly old) stellar population of the nuclear disc. Here we present our KMOS spectroscopic survey of the stars in the nuclear disk reaching the old populations. In order to obtain an unbiased data set, we sample stars in the full extinction range along each line-of-sight. We also observe reference fields in neighboring regions of t…
The EPS Research Astro-RAG Platform: A Unified Open-Science Infrastructure for Cross-Epoch Astrophysical Kinematic Analysis, LLM-Assisted Research Workflows, and Educational Outreach
As part of our KMOS AGN Survey at High-redshift (KASHz), we present spatially-resolved VLT/KMOS and VLT/SINFONI spectroscopic data and ALMA 870$μ$m continuum imaging of eight $z$=1.4--2.6 moderate AGN ($L_{\rm 2-10 \rm kev}$ = $10^{42} - 10^{45}$ ergs s$^{-1}$). We map [OIII], H$α$ and rest-frame FIR emission to search for any spatial anti-correlation between ionised outflows (traced by the [OIII] line) and star formation (SF; traced by H$α$ and FIR), that has previously been claimed for some high-z AGN and used as evidence for negative and/or positive AGN feedback. Firstly, we conclude that H…
First spectroscopic identification of the main sequence in Westerlund 1
Centro de Astrobiología (CSIC-INTA)（天体生物学中心）；Universidad Autónoma de Madrid（马德里自治大学）；Facultad de Ciencias, Universidad de Alicante（阿利坎特大学理学院）；The Open University（开放大学）；Tel Aviv University（特拉维夫大学）；University College London（伦敦大学学院）；Square Kilometre Array Observatory（平方公里阵列射电望远镜）
We present detailed stellar specific angular momentum ($j_*$) measurements of ten star-forming galaxies at $z\sim1.5-2$ using both high and low spatial resolution integral field spectroscopic data. We developed a code that simultaneously models the adaptive optics (AO) assisted observations from OSIRIS/SINFONI along with their natural seeing (NS) counterparts from KMOS at spatial resolutions of [$0.1-0.4$] arcsec and [$0.6-1.0$] arcsec respectively. The AO data reveals 2/10 systems to be mergers and for the remaining eight the mean uncertainties $\bar Δj_*$ decrease from 49% (NS), and 26.5% (A…
We use multi-object near-infrared (NIR) spectroscopy with VLT/KMOS to investigate the role of the environment in the evolution of the ionized gas properties of narrow-band selected H$α$ emitters (HAEs) in the Spiderweb protocluster at $z=2.16$. Based on rest-frame optical emission lines, H$α$ and [NII]$λ$6584, we confirm the cluster membership of 39 of our targets (i.e. 93% success rate), and measure their star-formation rates (SFR), gas-phase oxygen abundances and effective radius. We parametrize the environment where our targets reside by using local and global density indicators based on pr…
Rest-frame Optical Emission Lines in Far-Infrared Selected Galaxies at z<1.7 from the FMOS-COSMOS Survey
我们利用Subaru上的FMOS获得了COSMOS中123个远红外选定星系的近红外光谱，并获得了关键的静止标架光发射谱线。这是在这些红移下具有近红外光谱的红外星系的最大样本。远红外选择的结果是在一个大规模的系统，跨越一系列的金属丰度与以前的光学选择的调查相比，星系的样本，因此有一个更高的活动星系核分数和更好的样本活动星系核分支。我们在两个红移仓（z~0.7和z~1.5）中确定了（U）LIRGs中是否存在活动星系核和星暴，并测试了用于分离活动星系核和以恒星形成为主的星系的诊断方法的红移依赖性。此外，我们构建了一个红外选择星系的低红移（z~0.1）比较样本，发现从z~1.5到今天的演化与Kewley et al.（2013 b）模型中不断演化的AGN选择线和一系列ISM条件和金属丰度一致。我们发现，很大一部分的（U）LIRGs的BPT选择AGN使用他们的新的，红移依赖的分类线。我们比较了已知的X射线探测到的活动星系核（共67个）的位置与BPT选择，发现新的分类线准确地选择了大多数这些对象（> 70%）。此外，我们确定了35个新的（可能被遮蔽）活动星系核没有选择这样的X射线发射。我们的研究结果有直接的影响活动星系核的选择在较高的红移与当前（MOSFIRE，KMOS）或未来（PFS，MOONS）的光谱努力与近红外光谱覆盖。
We study the molecular gas content of 24 star-forming galaxies at $z=3-4$, with a median stellar mass of $10^{9.1}$ M$_{\odot}$, from the MUSE Hubble Ultra Deep Field (HUDF) Survey. Selected by their Lyman-alpha-emission and H-band magnitude, the galaxies show an average EW $\approx 20$ angstrom, below the typical selection threshold for Lyman Alpha Emitters (EW $> 25$ angstrom), and a rest-frame UV spectrum similar to Lyman Break Galaxies. We use rest-frame optical spectroscopy from KMOS and MOSFIRE, and the UV features observed with MUSE, to determine the systemic redshifts, which are offset…
We present medium-resolution (R $\sim$ 4000) YJ, H \& K band spectroscopy of candidate young stellar objects (YSOs) in NGC~346, the most active star-formation region in the metal-poor (Z = 1/5 Z$_{\sun}$) Small Magellanic Cloud. The spectra were obtained with the KMOS (K-Band Multi Object Spectrograph) integral field instrument on the Very Large Telescope. From our initial sample of 18 candidate high-mass YSOs previously identified from mid-IR photometry and radiative transfer model fits to their spectral energy distributions, approximately half were resolved into multiple components by our in…
Unresolved triple systems in the aged open cluster Trumpler 19: Discovery, confirmation, and implications
Universidad Andres Bello（安德斯贝洛大学）；Vatican Observatory（梵蒂冈天文台）；Universidade Federal de Santa Catarina（圣卡塔琳娜联邦大学）；European Southern Observatory（欧洲南方天文台）；University of Hertfordshire（赫特福德大学）；Universidad Bernardo O’Higgins（贝尔纳多·奥希金斯大学）；Universidad de Antofagasta（安托法加斯塔大学）
