- ID:
- ivo://CDS.VizieR/J/AJ/147/52
- Title:
- Structures in the Chandra Deep Field-South
- Short Name:
- J/AJ/147/52
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive structure detection analysis of the 0.3deg^2^ area of the MUSYC-ACES field, which covers the Chandra Deep Field-South (CDFS). Using a density-based clustering algorithm on the MUSYC and ACES photometric and spectroscopic catalogs, we find 62 overdense regions up to redshifts of 1, including clusters, groups, and filaments. We also present the detection of a relatively small void of ~10Mpc^2^ at z~0.53. All structures are confirmed using the DBSCAN method, including the detection of nine structures previously reported in the literature. We present a catalog of all structures present, including their central position, mean redshift, velocity dispersions, and classification based on their morphological and spectroscopic distributions. In particular, we find 13 galaxy clusters and 6 large groups/small clusters. Comparison of these massive structures with published XMM-Newton imaging (where available) shows that 80% of these structures are associated with diffuse, soft-band (0.4-1keV) X-ray emission, including 90% of all objects classified as clusters. The presence of soft-band X-ray emission in these massive structures (M_200_{>=}4.9x10^13^M_{sun}_) provides a strong independent confirmation of our methodology and classification scheme. In the closest two clusters identified (z<0.13) high-quality optical ur photometric sample contains 5522 galaxies imaging from the Deep2c field of the Garching-Bonn Deep Survey reveals the cD galaxies and demonstrates that they sit at the center of the detected X-ray emission. Nearly 60% of the clusters, groups, and filaments are detected in the known enhanced density regions of the CDFS at z=~0.13, 0.52, 0.68, and 0.73. Additionally, all of the clusters, bar the most distant, are found in these overdense redshift regions. Many of the clusters and groups exhibit signs of ongoing formation seen in their velocity distributions, position within the detected cosmic web, and in one case through the presence of tidally disrupted central galaxies exhibiting trails of stars. These results all provide strong support for hierarchical structure formation up to redshifts of 1.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/889/80
- Title:
- STUDIES. III. SCUBA-2 450um gal. with MIPS & VLA obs.
- Short Name:
- J/ApJ/889/80
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- We construct a SCUBA-2 450{mu}m map in the COSMOS field that covers an area of 300arcmin^2^ and reaches a 1{sigma} noise level of 0.65mJy in the deepest region. We extract 256 sources detected at 450{mu}m with signal-to-noise ratios >4.0 and analyze the physical properties of their multiwavelength counterparts. We find that most of the sources are at z<~3, with a median of z=1.79_-0.15_^+0.03^%. About 35_-25_^+32^% of our sources are classified as starburst galaxies based on their total star formation rates (SFRs) and stellar masses (M_*_). By fitting the far-infrared spectral energy distributions, we find that our 450{mu}m selected sample has a wide range of dust temperatures (20K<~T_d_<~60K), with a median of T_d_=38.3_-0.9_^+0.4^K. We do not find a redshift evolution in dust temperature for sources with L_IR_>10^12^L_{sun}_ at z<3. However, we find a moderate correlation where the dust temperature increases with the deviation from the SFR-M_*_ relation. The increase in dust temperature also correlates with optical morphology, which is consistent with merger-triggered starbursts in submillimeter galaxies. Our galaxies do not show the tight IRX-{beta}_UV_ correlation that has been observed in the local universe. We construct the infrared luminosity functions of our 450{mu}m sources and measure their comoving SFR densities (SFRDs). The contribution of the L_IR_>10^12^L_{sun}_ population to the SFRD rises dramatically from z=0 to 2 ({propto}(1+z)^3.9+/-1.1^) and dominates the total SFRD at z>~2.
- ID:
- ivo://CDS.VizieR/J/ApJ/865/103
- Title:
- STUDIES. II. NIR morphologies of submm galaxies
- Short Name:
- J/ApJ/865/103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present structural parameters and morphological properties of faint 450{mu}m selected submillimeter galaxies (SMGs) from the JCMT Large Program, STUDIES, in the COSMOS-CANDELS region. Their properties are compared to an 850{mu}m selected and a matched star-forming samples. We investigate stellar structures of 169 faint 450{mu}m sources (S_450_=2.8-29.6mJy; S/N>4) at z<3 using HST near-infrared observations. Based on our spectral energy distribution fitting, half of such faint SMGs (L_IR_=10^11.65^+/-0.98^L_{sun}_) lie above the star formation rate (SFR)/stellar mass plane. The size-mass relation shows that these SMGs are generally similar to less-luminous star-forming galaxies selected by NUV-r versus r-J colors. Because of the intrinsic luminosity of the sample, their rest-frame optical emission is less extended than the 850{mu}m sources (S_850_>2mJy) and more extended than the star-forming galaxies in the same redshift range. For the stellar mass and SFR-matched sample at z~1 and z~2, the size differences are marginal between faint SMGs and the matched galaxies. Moreover, faint SMGs have similar Sersic indices and projected axis ratios as star-forming galaxies with the same stellar mass and SFR. Both SMGs and the matched galaxies show high fractions (~70%) of disturbed features at z~2, and the fractions depend on the SFRs. These suggest that their star formation activity is related to galaxy merging and the stellar structures of SMGs are similar to those of star-forming galaxies. We show that the depths of submillimeter surveys are approaching the lower luminosity end of star-forming galaxies, allowing us to detect galaxies on the main sequence.
1374. Study of Abell 119
- ID:
- ivo://CDS.VizieR/J/AJ/105/788
- Title:
- Study of Abell 119
- Short Name:
- J/AJ/105/788
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report 60 new radial velocities, as well as new photographic and CCD photometry.
- ID:
- ivo://CDS.VizieR/J/ApJ/669/714
- Title:
- Subaru weak-lensing survey. I.
- Short Name:
- J/ApJ/669/714
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an ongoing weak-lensing survey conducted with the Subaru Telescope whose initial goal is to locate and study the distribution of shear-selected structures, or halos. Using a Suprime-Cam imaging survey spanning 21.82deg^2^, we present a catalog of 100 candidate halos located from lensing-convergence maps. Our sample is reliably drawn from that subset of our survey area (totaling 16.72deg^2^) uncontaminated by bright stars and edge effects and is limited at a convergence signal-to-noise ratio of 3.69. To validate the sample, detailed spectroscopic measures have been made for 26 candidates using the Subaru multiobject spectrograph, FOCAS. All are confirmed as clusters of galaxies, but two arise as the superposition of multiple clusters viewed along the line of sight. Including data available in the literature and an ongoing Keck spectroscopic campaign, a total of 41 halos now have reliable redshifts.
- ID:
- ivo://CDS.VizieR/J/ApJS/176/301
- Title:
- Subaru/XMM-Newton deep survey IV. (SXDS)
- Short Name:
- J/ApJS/176/301
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present luminosity functions (LFs) and various properties of Ly{alpha} emitters (LAEs) at z=3.1, 3.7, and 5.7, in a 1deg^2^ sky of the Subaru/XMM-Newton Deep Survey (SXDS) Field. We obtain a photometric sample of 858 LAE candidates based on deep Subaru Suprime-Cam imaging data and a spectroscopic sample of 84 confirmed LAEs from Subaru FOCAS and VLT VIMOS spectroscopy in a survey volume of ~10^6^Mpc^3^ with a limiting Ly{alpha} luminosity of ~3x10^42^ergs/s. We derive the LFs of the Ly{alpha} and UV continuum (~1500{AA}) for each redshift, taking into account the statistical error and the field-to-field variation. We identify six LAEs with AGN activities from our spectra combined with VLA, Spitzer, and XMM-Newton data. Among the photometrically selected LAEs at z=3.1 and 3.7, only ~1% show AGN activities, while the brightest LAEs with logL(Ly{alpha})>~43.4-43.6ergs/s appear to always host AGNs. Our LAEs are bluer in UV-continuum color than dropout galaxies, suggesting lower extinction and/or younger stellar populations.
- ID:
- ivo://CDS.VizieR/J/A+A/584/A62
- Title:
- SUDARE VST-OmegaCAM search supernova rates
- Short Name:
- J/A+A/584/A62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the observing strategy, data reduction tools, and early results of a supernova (SN) search project, named SUDARE, conducted with the ESO VST telescope, which is aimed at measuring the rate of the different types of SNe in the redshift range 0.2<z<0.8. The search was performed in two of the best studied extragalactic fields, CDFS and COSMOS, for which a wealth of ancillary data are available in the literature or in public archives. We developed a pipeline for the data reduction and rapid identification of transients. As a result of the frequent monitoring of the two selected fields, we obtained light curve and colour information for the transients sources that were used to select and classify SNe by means of an especially developed tool. To accurately characterise the surveyed stellar population, we exploit public data and our own observations to measure the galaxy photometric redshifts and rest frame colours. We obtained a final sample of 117 SNe, most of which are SN Ia (57%) with the remaining ones being core collapse events, of which 44% are type II, 22% type IIn and 34% type Ib/c. To link the transients, we built a catalogue of ~1.3x10^5^ galaxies in the redshift range 0<z<=1, with a limiting magnitude K_AB_=23.5mag. We measured the SN rate per unit volume for SN Ia and core collapse SNe in different bins of redshifts. The values are consistent with other measurements from the literature. The dispersion of the rate measurements for SNe-Ia is comparable to the scatter of the theoretical tracks for single degenerate (SD) and double degenerate (DD) binary systems models, therefore it is not possible to disentangle among the two different progenitor scenarios. However, among the three tested models (SD and the two flavours of DD that either have a steep DDC or a wide DDW delay time distribution), the SD appears to give a better fit across the whole redshift range, whereas the DDC better matches the steep rise up to redshift ~1.2. The DDW instead appears to be less favoured. Unlike recent claims, the core collapse SN rate is fully consistent with the prediction that is based on recent estimates of star formation history and standard progenitor mass range.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A148
- Title:
- SuGOHI VI. List up to 2020
- Short Name:
- J/A+A/642/A148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Strong lenses are extremely useful probes of the distribution of matter on galaxy and cluster scales at cosmological distances, but are rare and difficult to find. The number of currently known lenses is on the order of 1000. We wish to use crowdsourcing to carry out a lens search targeting massive galaxies selected from over 442 square degrees of photometric data from the Hyper Suprime-Cam (HSC) survey. We selected from the S16A internal data release of the HSC survey a sample of ~300000 galaxies with photometric redshifts in the range 0.2<zphot<1.2 and photometrically inferred stellar masses logM*>11.2. We crowdsourced lens finding on this sample of galaxies on the Zooniverse platform, as part of the Space Warps project. The sample was complemented by a large set of simulated lenses and visually selected non-lenses, for training purposes. Nearly 6000 citizen volunteers participated in the experiment. In parallel, we used YattaLens an automated lens finding algorithm, to look for lenses in the same sample of galaxies. Based on a statistical analysis of classification data from the volunteers, we selected a sample of the most promising ~1500 candidates which we then visually inspected: half of them turned out to be possible (grade C) lenses or better. Including lenses found by YattaLens or serendipitously noticed in the discussion section of the Space Warps website, we were able to find 14 definite lenses (grade A), 129 probable lenses (grade B) and 581 possible lenses. YattaLens found half the number of lenses discovered via crowdsourcing. Crowdsourcing is able to produce samples of lens candidates with high completeness and purity, compared to currently available automated algorithms. A hybrid approach, in which the visual inspection of samples of lens candidates pre-selected by discovery algorithms and/or coupled to machine learning is crowdsourced, will be a viable option for lens finding in the 2020s with forthcoming wide area surveys such as LSST, Euclid and WFIRST.
- ID:
- ivo://CDS.VizieR/J/AJ/130/896
- Title:
- SUMSS Giant Radio Sources
- Short Name:
- J/AJ/130/896
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a complete sample of megaparsec-sized double radio sources compiled from the Sydney University Molonglo Sky Survey (SUMSS, Cat. <VIII/70>). Almost complete redshift information has been obtained for the sample. The sample has the following defining criteria: Galactic latitude |b|>12.5{deg}, declination {delta}<-50{deg}, and angular size >5'. All the sources have a projected linear size larger than 0.7Mpc (assuming H_0_=71km/s/Mpc). The sample is chosen from a region of the sky covering 2100{deg}^2^. In this paper we present 843MHz radio images of the extended radio morphologies made using the Molonglo Observatory Synthesis Telescope, higher resolution radio observations of any compact radio structures using the Australia Telescope Compact Array, and low-resolution optical spectra of the host galaxies from the 2.3m Australian National University telescope at Siding Spring Observatory. The sample presented here is the first in the southern hemisphere and significantly enhances the database of known giant radio sources. The giant radio sources with linear size exceeding 0.7Mpc have an abundance of (215Mpc)^-3^ at the sensitivity of the survey. In the low-redshift universe, the survey may be suggesting the possibility that giant radio sources with relict lobes are more numerous than giant sources in which beams from the center currently energize the lobes.
- ID:
- ivo://CDS.VizieR/J/ApJS/253/3
- Title:
- Sunyaev-Zel'dovich galaxy clusters surveyed by ACT
- Short Name:
- J/ApJS/253/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 4195 optically confirmed Sunyaev-Zel'dovich (SZ) selected galaxy clusters detected with signal-to-noise ratio >4 in 13211deg^2^ of sky surveyed by the Atacama Cosmology Telescope (ACT). Cluster candidates were selected by applying a multifrequency matched filter to 98 and 150GHz maps constructed from ACT observations obtained from 2008 to 2018 and confirmed using deep, wide-area optical surveys. The clusters span the redshift range 0.04<z<1.91 (median z=0.52). The catalog contains 222 z>1 clusters, and a total of 868 systems are new discoveries. Assuming an SZ signal versus mass-scaling relation calibrated from X-ray observations, the sample has a 90% completeness mass limit of M_500c_>3.8x10^14^M_{sun}_, evaluated at z=0.5, for clusters detected at signal-to-noise ratio >5 in maps filtered at an angular scale of 2.4'. The survey has a large overlap with deep optical weak-lensing surveys that are being used to calibrate the SZ signal mass-scaling relation, such as the Dark Energy Survey (4566deg^2^), the Hyper Suprime-Cam Subaru Strategic Program (469deg^2^), and the Kilo Degree Survey (825deg^2^). We highlight some noteworthy objects in the sample, including potentially projected systems, clusters with strong lensing features, clusters with active central galaxies or star formation, and systems of multiple clusters that may be physically associated. The cluster catalog will be a useful resource for future cosmological analyses and studying the evolution of the intracluster medium and galaxies in massive clusters over the past 10Gyr.
