The ESO Slice Project (ESP) is a galaxy redshift survey in a region near the South Galactic Pole (see Vettolani et al., 1997A&A...325..954V; Zucca et al., 1997A&A...326..477Z). It extends over a strip 22(RA)x1(DEC) square degrees, plus a nearby area of 5x1 square degrees, 5 degrees west of the main strip. The right ascension limits are 22h30m and 01h20m, at a mean declination of -40{deg}15' (B1950). We have covered this region with a regular grid of adjacent circular fields, with a diameter of 32arcmin each, corresponding to the field of view of the multifiber spectrograph OPTOPUS at the 3.6m ESO telescope. The total solid angle of the spectroscopic survey is 23.2 square degrees. The galaxy catalogue has been extracted from the Edinburgh-Durham Southern Galaxy catalogue (Heydon-Dumbleton et al., 1989MNRAS.238..379H) which has been obtained from COSMOS (MacGillivray & Stobie, 1984VA.....27..433M) scans of SERC J survey plates. The number of objects in the photometric ESP sample is 4487. The spectroscopic survey is about 85% complete to the limiting magnitude bJ=19.4, and consists of 3342 galaxies + 1 QSO with redshift determination. The ESP survey is intermediate between shallow, wide angle samples and very deep, one--dimensional pencil beams. Table 2 lists the fields observed with OPTOPUS and their properties: the numbers listed in this table can be used to compute the redshift completeness of each fields, following eq.(2) of the paper. Table 3 provides the catalogue, with galaxies sorted in right ascension. The catalogue with additional information and updates can also be found at the following URL: http://boas5.bo.astro.it/~cappi/esokp.html
The survey is a joint project undertaken by the European Southern Observatory (ESO) and the Uppsala Observatory to provide a systematic and homogeneous search of the ESO(B) Atlas (also known as the Quick Blue Survey). The ESO(B) Atlas, taken with the ESO 1-m Schmidt telescope at La Silla, Chile, covers 606 fields from -90 to -20 degrees of declination. The fields are similar in size and scale to those of the Palomar Observatory Sky Survey. Unsensitized IIa-O plates and a 2-mm GG385 filter were used to give a passband similar to the Johnson B color. The actual search was conducted at the Uppsala Observatory and resulted in a list of nonstellar objects including all NGC and IC galaxies between -20 and -30 degrees declination, all galaxies down to a limiting diameter of 1.0 arcmin, all disturbed galaxies as faint as possible, all star clusters in the Catalog of Star Clusters and Associations (Alter et al. 1970) and smaller and fainter clusters if recognizable and all planetary nebulae listed in the available catalogs. The catalog includes coordinates, identifications, diameters, position angles, morphological types, classifications, magnitudes, colors, and radial velocities.
We have used the Plateau De Bure Interferometer to observe multiple CO and neutral carbon transitions in a z=2.2 main sequence disk galaxy, BX610. Our observation of CO(7-6), CO(4-3) and both far infrared [CI] lines complements previous observations of H-alpha and low-J CO, and reveal a galaxy that is vigorously forming stars with UV fields, (Log(G/G_0_)<3.25), less extreme than local ULIRGs or most starbursting submillimeter galaxies in the early universe. Our observations allow new independent estimates of the cold gas mass which indicate M_gas_~2x10^11^M_{sun}_, and suggest a modestly larger alpha_CO value of ~8.2. The corresponding gas depletion timescale is ~1.5Gyr. In addition to gas of modest density (Log(n[cm^-3^])<3) heated by star formation, BX610 shows evidence for a significant second gas component responsible for the strong high-J CO emission. This second component might either be a high density molecular gas component heated by star formation in a typical photodissociation region, or it could be molecular gas excited by low velocity C shocks. The CO(7-6) to far infrared luminosity ratio we observe is significantly higher than typical star forming galaxies and suggests that CO(7-6) is not a reliable star formation tracer in this galaxy.
Estimated distances for ~12000 galaxies with NED-D
Short Name:
J/AJ/160/199
Date:
21 Oct 2021
Publisher:
CDS
Description:
Numerous research topics rely on an improved cosmic distance scale (e.g., cosmology, gravitational waves) and the NASA/IPAC Extragalactic Database of Distances (NED-D) supports those efforts by tabulating multiple redshift-independent distances for 12000 galaxies (e.g., Large Magellanic Cloud (LMC) zero-point). Six methods for securing a mean estimate distance (MED) from the data are presented (e.g., indicator and Decision Tree). All six MEDs yield surprisingly consistent distances for the cases examined, including for the key benchmark LMC and M106 galaxies. The results underscore the utility of the NED-D MEDs in bolstering the cosmic distance scale and facilitating the identification of systematic trends.
We present a method to estimate the total gas column density, dust-to-gas and dust-to-metal ratios of distant galaxies from rest-frame optical spectra. The technique exploits the sensitivity of certain optical lines to changes in depletion of metals on to dust grains and uses photoionization models to constrain these physical ratios along with the metallicity and dust column density. We compare our gas column density estimates with HI and CO gas mass estimates in nearby galaxies to show that we recover their total gas mass surface density to within a factor of 2 up to a total surface gas mass density of ~75M{sun}/pc^2^. Our technique is independent of the conversion factor of CO to H_2_ and we show that a metallicity-dependent X_CO_ is required to achieve good agreement between our measurements and that provided by CO and HI. However, we also show that our method cannot be reliably aperture corrected to total integrated gas mass. We calculate dust-to-gas ratios for all star-forming galaxies in the Sloan Digital Sky Survey Data Release 7 and show that the resulting dependence on metallicity agrees well with the trend inferred from modelling of the dust emission of nearby galaxies using far-IR data. We also present estimates of the variation of the dust-to-metal ratio with metallicity and show that this is poorly constrained at metallicities below 50% solar. We conclude with a study of the inventory of gas in the central regions, defined both in terms of a fixed physical radius and as a fixed fraction of the half-light radius, of ~70000 star-forming galaxies from the Sloan Digital Sky Survey. We show that their central gas content and gas depletion time are not accurately predicted by a single parameter, but in agreement with recent studies we find that a combination of the stellar mass and some measure of central concentration provides a good predictor of gas content in galaxies. We also identify a population of galaxies with low surface densities of stars and very long gas depletion times.
We explore the properties of early-type galaxies (ETGs), including ellipticals (E) and lenticulars (S0), in rich environments, such as clusters of galaxies (Virgo and Coma). The L_24_/L_K_ distribution of ETGs in both Virgo and Coma clusters shows that some S0s have a much larger L_24_/L_K_ ratio (0.5 to ~2 dex) than the bulk of the ETG population. This could be interpreted as an enhanced star formation rate in these lenticulars. We compare the optical colors of galaxies in these two clusters and investigate the nature of these sources with a large L_24_/L_K_ ratio by looking at their spatial distribution within the cluster, analyzing their optical spectra, and looking at their optical colors compared to late-types. We obtain 10 Coma and 3 Virgo early-type sources with larger L_24_/L_K_ ratios than the bulk of their population. We call these sources mid-infrared enhanced galaxies (MIEGs). In Coma, they are mostly located in the southwest part of the cluster where a substructure is falling onto the main cluster. MIEGs present a lower g-r color than the rest of the ETG sample because of a blue continuum. We interpret the excess L_24_/L_K_ ratio as evidence for enhanced star formation induced as a consequence of their infall into the main cluster.
The Complete Calibration of the Color-Redshift Relation (C3R2) survey is obtaining spectroscopic redshifts in order to map the relation between galaxy color and redshift to a depth of i~24.5 (AB). The primary goal is to enable sufficiently accurate photometric redshifts for Stage IV dark energy projects, particularly Euclid and the Nancy Grace Roman Space Telescope (Roman), which are designed to constrain cosmological parameters through weak lensing. We present 676 new high-confidence spectroscopic redshifts obtained by the C3R2 survey in the 2017B-2019B semesters using the DEIMOS, LRIS, and MOSFIRE multiobject spectrographs on the Keck telescopes. Combined with the 4454 redshifts previously published by this project, the C3R2 survey has now obtained and published 5130 high-quality galaxy spectra and redshifts. If we restrict consideration to only the 0.2<z_p_<2.6 range of interest for the Euclid cosmological goals, then with the current data release, C3R2 has increased the spectroscopic redshift coverage of the Euclid color space from 51% (as reported by Masters+ 2017, J/ApJ/841/111) to the current 91%. Once completed and combined with extensive data collected by other spectroscopic surveys, C3R2 should provide the spectroscopic calibration set needed to enable photometric redshifts to meet the cosmology requirements for Euclid, and make significant headway toward solving the problem for Roman.
In this study we present a simple model of elliptical galaxies aimed at interpreting the gradients in colours and narrow band indices observed across these systems. Salient features of the model are the gradients in mass density and star formation and infall of primordial gas aimed at simulating the collapse of a galaxy into the potential well of dark matter. Adopting a multi-zone model we follow in detail the history of star formation, gas consumption, and chemical enrichment of the galaxy and also allow for the occurrence of galactic winds according to the classical supernova (and stellar winds) energy deposit. The outline of the model, the time scale of gas accretion and rate of star formation as a function of the galacto-centric distance in particular, seek to closely mimic the results from Tree-SPH dynamical models. Although some specific ingredients of the model can be questioned from many points of view (of which we are well aware), the model has to be considered as a gross tool for exploring the consequences of different recipes of gas accretion and star formation in which the simple one-zone scheme is abandoned. With the aid of this model we discuss the observational data on the gradients in metallicity, colours, and narrow band indices across elliptical galaxies.
We study the evolution of spectral early-type galaxies in clusters, groups, and the field up to redshift 0.9 using the ESO Distant Cluster Survey (EDisCS) dataset. We measure structural parameters (circularized half-luminosity radii Re, surface brightness Ie, and velocity dispersions sigma) for 154 cluster and 68 field galaxies. On average, we achieve precisions of 10% in Re, 0.1dex in logIe, and 10% in sigma. We sample ~20% of cluster and ~10% of field spectral early-type galaxies to an I band magnitude in a 1arcsec radius aperture as faint as I1=22. We study the evolution of the zero point of the fundamental plane (FP) and confirm results in the literature, but now also for the low cluster velocity dispersion regime.
In the concordance cosmological scenario, the cold collisionless dark matter component dominates the mass budget of galaxies and interacts with baryons only via gravity. However, there is growing evidence that the former, instead, responds to the baryonic (feedback) processes by modifying its density distribution. These processes can be captured by comparing the inner dynamics of galaxies across cosmic time. We present a pilot study of dynamical mass modeling of high redshift galaxy rotation curves, which is capable of constraining the structure of dark matter halos across cosmic time. We investigate the dark matter halos of 256 star-forming disk-like galaxies at z~1 using the KMOS Redshift One Spectroscopic Survey (KROSS). This sample covers the redshifts 0.6<=z<=1.04, effective radii 0.69<=Re[kpc]<=7.76, and total stellar masses 8.7<=log(Mstar [M])<=11.32. We present a mass modeling 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 disk, while for the latter we employ the NFW (cusp) and the Burkert (cored) halo profiles, separately. At the end, we compare the results of both cases with state-of-the-art galaxy simulations (EAGLE, TNG100, and TNG50). We find that the "cored" dark matter halo emerged as the dominant quantity from a radius 1-3 times the effective radius. Its fraction to the total mass is in good agreement with the outcome of hydrodynamical galaxy simulations. Remarkably, we found that the dark matter core of z~1 star-forming galaxies are smaller and denser than their local counterparts. Dark matter halos have gradually expanded over the past 6.5Gyrs. That is, observations are capable of capturing the dark matter response to the baryonic processes, thus giving us the first piece of empirical evidence of "gravitational potential fluctuations" in the inner region of galaxies that can be verified with deep surveys and future missions.