- ID:
- ivo://CDS.VizieR/J/A+A/399/813
- Title:
- Multiple merging events in Abell 521
- Short Name:
- J/A+A/399/813
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed spatial and dynamical analysis of the central ~2.2Mpc(Ho=75km/s/Mpc) region of the galaxy cluster Abell 521 (z=0.247), based on 238 spectra (of which 191 new measurements) obtained at the 3.6m Telescope of the European Southern Observatory and at the Canada-France-Hawaii Telescope. From the analysis of the 125 galaxies that are confirmed members of the cluster, we derive a location ("mean" velocity) of C_BI_=74019^{+112}^_{-125}_km/s and detect a complex velocity distribution with high velocity scale ("dispersion", S_BI_=1325^{+145}^_{-100}_km/s), but clear departure from a single Gaussian component. When excluding a possible background group of four galaxies, the velocity dispersion remains still large (~1200 km/s).
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- ID:
- ivo://CDS.VizieR/J/ApJ/668/643
- Title:
- Multiply imaged gravitational lens systems
- Short Name:
- J/ApJ/668/643
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a reconstruction of the mass distribution of galaxy cluster Abell 1689 at z=0.18 using detected strong lensing features from deep ACS observations and extensive ground based spectroscopy. Earlier analyses have reported up to 32 multiply imaged systems in this cluster, of which only 3 were spectroscopically confirmed. In this work, we present a parametric strong lensing mass reconstruction using 34 multiply imaged systems of which 24 have newly determined spectroscopic redshifts, which is a major step forward in building a robust mass model. In turn, the new spectroscopic data allows a more secure identification of multiply imaged systems.
- ID:
- ivo://CDS.VizieR/J/ApJ/817/60
- Title:
- Multiply imaged supernova Refsdal
- Short Name:
- J/ApJ/817/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Supernova "Refsdal", multiply imaged by cluster MACS1149.5+2223, represents a rare opportunity to make a true blind test of model predictions in extragalactic astronomy, on a timescale that is short compared to a human lifetime. In order to take advantage of this event, we produced seven gravitational lens models with five independent methods, based on Hubble Space Telescope (HST) Hubble Frontier Field images, along with extensive spectroscopic follow-up observations by HST, the Very Large and the Keck Telescopes. We compare the model predictions and show that they agree reasonably well with the measured time delays and magnification ratios between the known images, even though these quantities were not used as input. This agreement is encouraging, considering that the models only provide statistical uncertainties, and do not include additional sources of uncertainties such as structure along the line of sight, cosmology, and the mass sheet degeneracy. We then present the model predictions for the other appearances of supernova "Refsdal". A future image will reach its peak in the first half of 2016, while another image appeared between 1994 and 2004. The past image would have been too faint to be detected in existing archival images. The future image should be approximately one-third as bright as the brightest known image (i.e., H_AB_~25.7mag at peak and H_AB_~26.7mag six months before peak), and thus detectable in single-orbit HST images. We will find out soon whether our predictions are correct.
- ID:
- ivo://CDS.VizieR/J/ApJ/851/33
- Title:
- Multi-wavelength analysis of CGRaBS blazars
- Short Name:
- J/ApJ/851/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a multi-frequency, time-averaged analysis of blazars included in the Candidate Gamma-ray Blazar Survey catalog. Our sample consists of 324 {gamma}-ray detected ({gamma}-ray loud) and 191 {gamma}-ray undetected ({gamma}-ray quiet) blazars; we consider all the data up to 2016 April 1. We find that both the {gamma}-ray loud and {gamma}-ray quiet blazar populations occupy similar regions in the WISE color-color diagram, and {gamma}-ray loud sources are brighter in the radio and X-ray bands. A simple one-zone synchrotron inverse-Compton emission model is applied to derive the physical properties of both populations. We find that the central black hole mass and accretion disk luminosity (L_disk_) computed from the modeling of the optical-UV emission with a Shakura-Sunyaev disk reasonably matches that estimated from the optical spectroscopic emission-line information. A significantly larger Doppler boosting in the {gamma}-ray loud blazars is noted, and their jets are more radiatively efficient. On the other hand, the {gamma}-ray quiet objects are more MeV-peaked and thus could be potential targets for next-generation MeV missions. Our results confirm earlier findings about the accretion-jet connection in blazars; however, many of the {gamma}-ray quiet blazars tend to deviate from the recent claim that the jet power exceeds L_disk_ in blazars. A broadband study, considering a larger set of {gamma}-ray quiet objects and also including BL Lacs, will be needed to confirm/reject this hypothesis as well as to verify the evolution of the powerful high-redshift blazars into their low-power nearby counterparts.
- ID:
- ivo://CDS.VizieR/J/A+A/507/1277
- Title:
- Multiwavelength photometry of CDFS X-ray sources
- Short Name:
- J/A+A/507/1277
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The co-evolution of host galaxies and the active black holes which reside in their centre is one of the most important topics in modern observational cosmology. Here we present a study of the properties of obscured active galactic nuclei (AGN) detected in the CDFS 1 Ms observation and their host galaxies. We limited the analysis to the MUSIC area, for which deep K-band observations obtained with ISAAC@VLT are available, ensuring accurate identifications of the counterparts of the X-ray sources as well as reliable determination of photometric redshifts and galaxy parameters, such as stellar masses and star formation rates. In particular, we: 1) refined the X-ray/infrared/optical association of 179 sources in the MUSIC area detected in the Chandra observation; 2) studied the host galaxies observed and rest frame colors and properties.
- ID:
- ivo://CDS.VizieR/J/ApJ/761/114
- Title:
- Multi-wavelength study of clusters of galaxies. II.
- Short Name:
- J/ApJ/761/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galaxy clusters provide powerful laboratories for the study of galaxy evolution, particularly the origin of correlations of morphology and star formation rate (SFR) with density. We construct visible to MIR spectral energy distributions of galaxies in eight low-redshift (z<0.3) clusters and use them to measure stellar masses and SFRs as a function of environment. A partial correlation analysis indicates that the SFRs of star-forming galaxies (SFGs) depend strongly on M_*_ (>99% confidence) with no dependence on R/R_200_ or projected local density at fixed mass. A merged sample of galaxies from the five best measured clusters shows <SFR>{prop.to}(R/R_200_)^1.1+/-0.3^ for galaxies with R/R_200_<=0.4. A decline in the fraction of SFGs toward the cluster center contributes most of this effect, but it is accompanied by a reduction in <SFR> for SFGs with R<=0.1R_200_. The increase in the fraction of SFGs toward larger R/R_200_ and the isolation of SFGs with reduced SFRs near the cluster center are consistent with the truncation of star formation by ram-pressure stripping, as is the tendency for more massive SFGs to have higher SFRs. We conclude that stripping is more likely than slower processes to drive the properties of SFGs with R<0.4R_200_ in clusters. We also find that galaxies near the cluster center are more massive than galaxies farther out in the cluster at ~3.5{sigma}, which suggests that dynamical relaxation significantly impacts the distribution of cluster galaxies as the clusters evolve.
- ID:
- ivo://CDS.VizieR/J/A+A/392/795
- Title:
- Multi-wavelength study of 2 galaxy clusters
- Short Name:
- J/A+A/392/795
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from optical, X-ray and radio observations of two X-ray bright (L_X_~10^45^erg/s) galaxy clusters. Abell 1451 is at redshift z=0.1989 and has line-of-sight velocity dispersion {sigma}_V_=1330km/s as measured from 57 cluster galaxies. It has regular X-ray emission without signs of substructure, a Gaussian velocity distribution, lack of a cooling flow region and significant deviations from the observed scaling laws between luminosity, temperature and velocity dispersion, indicating a possible merging shock. There is only one spectroscopically confirmed cluster radio galaxy, which is close to the X-ray peak. 1RXS J131423.6-251521 (for short RXJ1314-25) has z=0.2474 and {sigma}_V_=1100km/s from 37 galaxies. There are two distinct galaxy groups with a projected separation of ~700kpc. The velocity histogram is bi-modal with a redshift-space separation of ~1700km/s, and the X-ray emission is double peaked. Although there are no spectroscopically confirmed cluster radio galaxies, we have identified a plausible relic source candidate.
- ID:
- ivo://CDS.VizieR/J/A+A/575/A75
- Title:
- MUSE 3D view of HDF-S
- Short Name:
- J/A+A/575/A75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We observed Hubble Deep Field South with the new panoramic integral-field spectrograph MUSE that we built and have just commissioned at the VLT. The data cube resulting from 27h of integration covers one arcmin^2^ field of view at an unprecedented depth with a 1{sigma} emission-line surface brightness limit of 1x10^-19^erg/s/cm2/arcsec2, and contains ~90000 spectra. We present the combined and calibrated data cube, and we performed a first-pass analysis of the sources detected in the Hubble Deep Field South imaging. We measured the redshifts of 189 sources up to a magnitude I_814_=29.5, increasing the number of known spectroscopic redshifts in this field by more than an order of magnitude. We also discovered 26 Ly{alpha} emitting galaxies that are not detected in the HST WFPC2 deep broad-band images. The intermediate spectral resolution of 2.3{AA} allows us to separate resolved asymmetric Ly{alpha} emitters, [OII]3727 emitters, and [CIII]1908 emitters, and the broad instantaneous wavelength range of 4500{AA} helps to identify single emission lines, such as [OIII]5007, H{beta}, and H{alpha}, over a very wide redshift range. We also show how the three-dimensional information of MUSE helps to resolve sources that are confused at ground-based image quality. Overall, secure identifications are provided for 83% of the 227 emission line sources detected in the MUSE data cube and for 32% of the 586 sources identified in the HST catalogue. The overall redshift distribution is fairly flat to z=6.3, with a reduction between z=1.5 to 2.9, in the well-known redshift desert. The field of view of MUSE also allowed us to detect 17 groups within the field. We checked that the number counts of [OII]3727 and Ly{alpha} emitters are roughly consistent with predictions from the literature. Using two examples, we demonstrate that MUSE is able to provide exquisite spatially resolved spectroscopic information on the intermediate-redshift galaxies present in the field. This unique data set can be used for a wide range of follow-up studies. We release the data cube, the associated products, and the source catalogue with redshifts, spectra, and emission-line fluxes.
- ID:
- ivo://CDS.VizieR/J/A+A/608/A2
- Title:
- MUSE Hubble Ultra Deep Field Survey. II.
- Short Name:
- J/A+A/608/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a two-layered spectroscopic survey (1'x1' ultra deep and 3'x3'deep regions) in the Hubble Ultra Deep Field (HUDF) with the Multi Unit Spectroscopic Explorer (MUSE). The combination of a large field of view, high sensitivity, and wide wavelength coverage provides an order of magnitude improvement in spectroscopically confirmed redshifts in the HUDF; i.e., 1206 secure spectroscopic redshifts for Hubble Space Telescope (HST) continuum selected objects, which corresponds to 15% of the total (7904). The redshift distribution extends well beyond z>3 and to HST/F775W magnitudes as faint as ~=30mag (AB, 1{sigma}). In addition, 132 secure redshifts were obtained for sources with no HST counterparts that were discovered in the MUSE data cubes by a blind search for emission-line features. In total, we present 1338 high quality redshifts, which is a factor of eight increase compared with the previously known spectroscopic redshifts in the same field. We assessed redshifts mainly with the spectral features [OII] at z<1.5 (473 objects) and Ly{alpha} at 2.9<z<6.7 (692 objects). With respect to F775W magnitude, a 50% completeness is reached at 26.5mag for ultra deep and 25.5mag for deep fields, and the completeness remains >=20% up to 28-29mag and ~=27mag, respectively. We used the determined redshifts to test continuum color selection (dropout) diagrams of high-z galaxies. The selection condition for F336W dropouts successfully captures ~=80% of the targeted z~2.7 galaxies. However, for higher redshift selections (F435W, F606W, and F775W dropouts), the success rates decrease to ~=20-40%. We empirically redefine the selection boundaries to make an attempt to improve them to ~=60%. The revised boundaries allow bluer colors that capture Ly{alpha} emitters with high Ly{alpha} equivalent widths falling in the broadbands used for the color-color selection. Along with this paper, we release the redshift and line flux catalog.
- ID:
- ivo://CDS.VizieR/J/A+A/624/A141
- Title:
- MUSE-Wide Survey DR1 catalog
- Short Name:
- J/A+A/624/A141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the MUSE-Wide survey, a blind, 3D spectroscopic survey in the CANDELS/GOODS-S and CANDELS/COSMOS regions. The final survey will cover 100x1arcmin^2^ MUSE fields. Each MUSE-Wide pointing has a depth of one hour and hence targets more extreme and more luminous objects over ten times the area of the MUSE-Deep fields (Bacon et al., 2017A&A...608A...1B). The legacy value of MUSE-Wide lies in providing "spectroscopy of everything" without photometric pre-selection. We describe the data reduction, post-processing and PSF characterization of the first 44 CANDELS/GOODS-S MUSE-Wide pointings released with this publication. Using a 3D matched filtering approach we detect 1602 emission line sources, including 479 Lyman-{alpha} (Lya) emitting galaxies with redshifts 2.9<~z<~6.3. We cross-matched the emission line sources to existing photometric catalogs, finding almost complete agreement in redshifts (photometric and spectroscopic) and stellar masses for our low redshift (z<1.5) emitters. At high redshift, we only find ~55% matches to photometric catalogs. We encounter a higher outlier rate and a systematic offset of {Delta}z~=0.2 when comparing our MUSE redshifts with photometric redshifts from the literature. Cross-matching the emission line sources with X-ray catalogs from the Chandra Deep Field South, we find 127 matches, mostly in agreement with the literature redshifts, including ten objects with no prior spectroscopic identification. Stacking X-ray images centered on our Lya emitters yields no signal; the Lya population is not dominated by even low luminosity AGN. Other cross-matches of our emission-line catalog to radio and submm data, yielded far lower numbers of matches, most of which already were covered by the X-ray catalog. A total of 9205 photometrically selected objects from the CANDELS survey lie in the MUSE-Wide footprint, of which we provide optimally extracted 1D spectra. We are able to determine the spectroscopic redshift of 98% of 772 photometrically selected galaxies brighter than 24th F775W magnitude. All the data in the first data release - datacubes, catalogs, extracted spectra, maps - are available on the website https://musewide.aip.de.