- ID:
- ivo://CDS.VizieR/J/ApJ/653/1004
- Title:
- Galaxies at 1.4<~z<~3.0 in GOODS-North Field
- Short Name:
- J/ApJ/653/1004
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a spectroscopic survey with LRIS-B on Keck of more than 280 star-forming galaxies and AGNs at redshifts 1.4~<z~<3.0 in the GOODS-N field. Candidates are selected by their UnGR colors using the "BM/BX" criteria to target redshift 1.4~<z~<2.5 galaxies and the LBG criteria to target redshift z~3 galaxies; combined these samples account for ~25%-30% of the R and Ks band counts to R=25.5 and Ks(AB)=24.4, respectively. The 212 BM/BX galaxies and 74 LBGs constitute the largest spectroscopic sample of galaxies at z>1.4 in GOODS-N. Extensive multiwavelength data allow us to investigate the stellar populations, stellar masses, bolometric luminosities (Lbol), and extinction z~2 of galaxies. Deep Chandra and Spitzer data indicate that the sample includes galaxies with a wide range in Lbol (~10^10^ to >10^12^L_{sun}_) and 4 orders of magnitude in dust obscuration (Lbol/LUV).
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/835/113
- Title:
- Galaxies >~6 from the Hubble Frontier Fields
- Short Name:
- J/ApJ/835/113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report a new analysis of the Hubble Frontier Fields clusters Abell2744 and MACS 0416 using wavelet decomposition to remove the cluster light, enabling the detection of highly magnified (>50x) galaxies a factor of 10x fainter in luminosity than previous studies. We find 167 galaxies at z>~6, and with this sample we are able to characterize the UV luminosity function to M_UV_=-12.5 at z~6, -14 at z~7, and -15 at z~8. We find a steep faint-end slope ({alpha}< -2), and with our improved statistics at the faint end we reduce the fractional uncertainty on {alpha} to <2% at z~6-7 and 4% at z~8. We also investigate the systematic uncertainty due to the lens modeling by using every available lens model individually and comparing the results; this systematic fractional uncertainty on {alpha} is <4% at all redshifts. We now directly observe galaxies in the luminosity regime where some simulations predict a change in the faint-end slope of the luminosity function, yet our results provide statistically very strong evidence against any turnover in the luminosity range probed, more consistent with simulations in which stars form in lower-mass halos. Thus, we find strong support for the extension of the steep luminosity function to M_UV_=-13 at z>6, consistent with the number of faint galaxies needed to reionize the universe under standard assumptions.
- ID:
- ivo://CDS.VizieR/J/ApJS/78/1
- Title:
- Galaxies in 7 clusters 0.35<z<0.55
- Short Name:
- J/ApJS/78/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry and spectroscopy for seven deep fields containing distant clusters of galaxies with 0.35<z<0.55. Positions and photometric parameters, including r-magnitudes g-r and r-i colors, surface brightnesses, and photometric profile types are given for about 2000 galaxies. Low-resolution spectroscopy is obtained from which redshifts are determined for 289 objects, of which 190 are cluster members.
- ID:
- ivo://CDS.VizieR/J/MNRAS/467/4220
- Title:
- Galaxies inside 120 arcsec of HE 0435-1223
- Short Name:
- J/MNRAS/467/4220
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on spectroscopy and multiband wide-field observations of the gravitationally lensed quasar HE 0435-1223, we determine the probability distribution function of the external convergence {kappa}_ext_ for this system. We measure the under/overdensity of the line of sight towards the lens system and compare it to the average line of sight throughout the Universe, determined by using the CFHTLenS (The Canada France Hawaii Lensing Survey) as a control field. Aiming to constrain {kappa}_ext_ as tightly as possible, we determine under/overdensities using various combinations of relevant informative weighting schemes for the galaxy counts, such as projected distance to the lens, redshift and stellar mass. We then convert the measured under/overdensities into a {kappa}_ext_ distribution, using ray-tracing through the Millennium Simulation. We explore several limiting magnitudes and apertures, and account for systematic and statistical uncertainties relevant to the quality of the observational data, which we further test through simulations. Our most robust estimate of {kappa}_ext_ has a median value {kappa}^med^_ext_=0.004 and a standard deviation {sigma}_{kappa}_=0.025. The measured {sigma}_{kappa}_ corresponds to 2.5 per cent relative uncertainty on the time delay distance, and hence the Hubble constant H_0_ inferred from this system. The median {kappa}^med^_ext_ value varies by ~0.005 with the adopted aperture radius, limiting magnitude and weighting scheme, as long as the latter incorporates galaxy number counts, the projected distance to the main lens and a prior on the external shear obtained from mass modelling. This corresponds to just ~0.5 per cent systematic impact on H_0_. The availability of a well-constrained {kappa}_ext_ makes HE 0435-1223 a valuable system for measuring cosmological parameters using strong gravitational lens time delays.
- ID:
- ivo://CDS.VizieR/J/ApJ/816/98
- Title:
- Galaxies in X-ray clusters with DES. I. Stellar mass
- Short Name:
- J/ApJ/816/98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the science verification data of the Dark Energy Survey for a new sample of 106 X-ray selected clusters and groups, we study the stellar mass growth of bright central galaxies (BCGs) since redshift z~1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into an analysis of a redshift-dependent BCG-cluster mass relation, m_*_{propto}(M_200_/1.5x10^14^M_{sun}_)^0.24+/-0.08^(1+z)^-0.19+/-0.34, and compare the observed relation to the model prediction. We estimate the average growth rate since z=1.0 for BCGs hosted by clusters of M_200,z_=10^13.8^M_{sun}_; at z=1.0: m_*,BCG_ appears to have grown by 0.13+/-0.11dex, in tension at the ~2.5{sigma} significance level with the 0.40 dex growth rate expected from the semi-analytic model. We show that the build-up of extended intracluster light after z=1.0 may alleviate this tension in BCG growth rates.
- ID:
- ivo://CDS.VizieR/J/ApJ/742/125
- Title:
- Galaxies in X-ray groups. I. COSMOS memberships
- Short Name:
- J/ApJ/742/125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Understanding the mechanisms that lead dense environments to host galaxies with redder colors, more spheroidal morphologies, and lower star formation rates than field populations remains an important problem. As most candidate processes ultimately depend on host halo mass, accurate characterizations of the local environment, ideally tied to halo mass estimates and spanning a range in halo mass and redshift, are needed. In this work, we present and test a rigorous, probabilistic method for assigning galaxies to groups based on precise photometric redshifts and X-ray-selected groups drawn from the COSMOS field. The groups have masses in the range 10^13^<~M_200c_/M_{sun}_<~10^14^ and span redshifts 0<z<1. We characterize our selection algorithm via tests on spectroscopic subsamples, including new data obtained at the Very Large Telescope, and by applying our method to detailed mock catalogs. We find that our group member galaxy sample has a purity of 84% and completeness of 92% within 0.5R_200c_. We measure the impact of uncertainties in redshifts and group centering on the quality of the member selection with simulations based on current data as well as future imaging and spectroscopic surveys. As a first application of our new group member catalog which will be made publicly available, we show that member galaxies exhibit a higher quenched fraction compared to the field at fixed stellar mass out to z~1, indicating a significant relationship between star formation and environment at group scales. We also address the suggestion that dusty star-forming galaxies in such groups may impact the high-l power spectrum of the cosmic microwave background and find that such a population cannot explain the low power seen in recent Sunyaev-Zel'dovich measurements.
- ID:
- ivo://CDS.VizieR/J/ApJ/853/95
- Title:
- Galaxies probing galaxies in PRIMUS. I.
- Short Name:
- J/ApJ/853/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The spectroscopy of background QSO sightlines passing close to foreground galaxies is a potent technique for studying the circumgalactic medium (CGM). However, QSOs are effectively point sources, limiting their potential to constrain the size of circumgalactic gaseous structures. Here we present the first large Keck/Low-resolution Imaging Spectrometer (LRIS) and Very Large Telescope (VLT)/Focal Reducer/Low-dispersion Spectrograph 2 (FORS2) spectroscopic survey of bright (B_AB_<22.3) background galaxies whose lines of sight probe MgII{lambda}{lambda}2796,2803 absorption from the CGM around close projected foreground galaxies at transverse distances 10kpc<R_{perp}_<150kpc. Our sample of 72 projected pairs, drawn from the PRIsm MUlti-object Survey, includes 48 background galaxies that do not host bright active galactic nuclei, and both star-forming and quiescent foreground galaxies with stellar masses of 9.0<logM_*_/M_{sun}_<11.2 at redshifts of 0.35<z_f/g_<0.8. We detect MgII absorption associated with these foreground galaxies with equivalent widths of 0.25{AA}<W_2796_<2.6{AA} at >2{sigma} significance in 20 individual background sightlines passing within R_{perp}_<50kpc and place 2{sigma} upper limits on W_2796_ of <~0.5{AA} in an additional 11 close sightlines. Within R_{perp}_<50kpc, W_2796_ is anticorrelated with R_{perp}_, consistent with analyses of Mg ii absorption detected along background QSO sightlines. Subsamples of these foreground hosts divided at logM_*_/M_{sun}_=9.9 exhibit statistically inconsistent W_2796_ distributions at 30kpc<R_{perp}_<50kpc, with the higher-M* galaxies yielding a larger median W_2796_ by 0.9{AA}. Finally, we demonstrate that foreground galaxies with similar stellar masses exhibit the same median W_2796_ at a given R_{perp}_ to within <0.2{AA} toward both background galaxies and toward QSO sightlines drawn from the literature. Analysis of these data sets constraining the spatial coherence scale of circumgalactic MgII absorption is presented in a companion paper.
- ID:
- ivo://CDS.VizieR/J/ApJS/107/521
- Title:
- Galaxies redshifts, 210<l<360, |b|<15
- Short Name:
- J/ApJS/107/521
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a redshift survey of an IRAS flux-limited (f_60_>0.6) galaxy sample behind the southern Milky Way, 210{deg}<l<360{deg} at |b|<15{deg}. The survey includes redshifts for 951 galaxies, ~500 of which are new. Of these 951 galaxies, 462 are in the zone 5{deg}<b<15{deg} and 353 are in the zone -15{deg}<b<-5{deg}. Though the innermost region of the Milky Way (|b|=5{deg}) remains opaque except in the longitude near 240, the detected galaxies show a high degree of completeness (~70%) in the zones 5{deg}<b<15{deg} and -15{deg}<b<-5{deg}. The cone diagrams exhibiting the detailed distribution of IRAS galaxies in the region 210{deg}<l<360{deg}, |b|<15{deg} shows two clusters in the Puppis region (l=240{deg}, b=-7{deg}, v=2400km/s; l=245{deg}, b=-5{deg}, v=7500km/s), the A3627 cluster (l=325{deg}, b=-7{deg}; v=4500km/s), the S4 cluster (l=280{deg}, b=7{deg}; v=5500km/s), and a possible void at l=245{deg}, v=3000km/s. The region 270{deg}<l<350{deg} is dominated by overdensity of galaxies representing the extension of the Hydra-Centaurus complex in the positive latitudes and the Pavo-Indus complex in the negative latitudes. A velocity histogram of galaxies in the GA region 290{deg}<l<350{deg}, |b|<15{deg}. reveals a substantial overdensity of galaxies in the velocity range 2400-5000km/s. The centroid of this overdensity is located at 4000km/s. The broad increased density of galaxies seen in our data corresponds with the distant concentration seen at 4500km/s in the supergalactic plane survey that covers the same longitude range like ours in l, but a larger range in latitude b (-30{deg} to -10{deg} and +10{deg} to +45{deg}). This lends support to the idea that the overdensity extends all the way from the Centaurus-Hydra complex (l=302{deg}, b=+22{deg}) in the north to the major concentration of the Pavo-Indus supercluster (l=332{deg}, b=-24{deg}) in the south, through the Milky Way. We conclude that the peak of the overdensity responsible for the peculiar velocity field in the local region is possibly situated in the Milky Way itself.
- ID:
- ivo://CDS.VizieR/J/AJ/131/2018
- Title:
- Galaxies with large velocity dispersions
- Short Name:
- J/AJ/131/2018
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the results of a search for galaxies with large (350>=km/s) velocity dispersions. The largest systems we have found appear to be the extremes of the early-type galaxy population: compared to other galaxies with similar luminosities, they have the largest velocity dispersions and the smallest sizes.
- ID:
- ivo://CDS.VizieR/J/MNRAS/474/3875
- Title:
- Galaxy And Mass Assembly (GAMA): DR3
- Short Name:
- J/MNRAS/474/3875
- Date:
- 19 Jan 2022 09:03:58
- Publisher:
- CDS
- Description:
- We describe data release 3 (DR3) of the Galaxy And Mass Assembly (GAMA) survey. The GAMA survey is a spectroscopic redshift and multiwavelength photometric survey in three equatorial regions each of 60.0deg^2^ (G09, G12, and G15), and two southern regions of 55.7deg^2^ (G02) and 50.6deg^2^ (G23). DR3 consists of: the first release of data covering the G02 region and of data on H-ATLAS (Herschel - Astrophysical Terahertz Large Area Survey) sources in the equatorial regions; and updates to data on sources released in DR2. DR3 includes 154809 sources with secure redshifts across four regions. A subset of the G02 region is 95.5 per cent redshift complete to r<19.8mag over an area of 19.5deg^2^, with 20086 galaxy redshifts, that overlaps substantially with the XXL survey (X-ray) and VIPERS (redshift survey). In the equatorial regions, the main survey has even higher completeness (98.5 per cent), and spectra for about 75 per cent of H-ATLAS filler targets were also obtained. This filler sample extends spectroscopic redshifts, for probable optical counterparts to H-ATLAS submillimetre sources, to 0.8mag deeper (r<20.6mag) than the GAMA main survey. There are 25814 galaxy redshifts for H-ATLAS sources from the GAMA main or filler surveys. GAMA DR3 is available at the survey website (www.gama-survey.org/dr3/).
