- ID:
- ivo://CDS.VizieR/J/A+A/647/A152
- Title:
- Tully-Fisher relation in MAGIC groups
- Short Name:
- J/A+A/647/A152
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galaxies in dense environments are subject to interactions and mechanisms that directly affect their evolution by lowering their gas fractions and consequently reducing their star-forming capacity earlier than their isolated counterparts. The aim of our project is to get new insights into the role of environment in the stellar and baryonic content of galaxies using a kinematic approach, through the study of the Tully-Fisher relation (TFR). We study a sample of galaxies in eight groups, over-dense by a factor larger than 25 with respect to the average projected density, spanning a redshift range of 0.5<z<0.8 and located in ten pointings of the MAGIC MUSE Guaranteed Time Observations program. We perform a morpho-kinematics analysis of this sample and set up a selection based on galaxy size, [OII]{lambda}{lambda}3727,3729 emission line doublet signal-to-noise ratio, bulge-to-disk ratio, and nuclear activity to construct a robust kinematic sample of 67 star-forming galaxies. We show that this selection considerably reduces the number of outliers in the TFR, which are predominantly dispersion-dominated galaxies. Similar to other studies, we find that including the velocity dispersion in the velocity budget mainly affects galaxies with low rotation velocities, reduces the scatter in the relation, increases its slope, and decreases its zero-point. Including gas masses is more significant for low-mass galaxies due to a larger gas fraction, and thus decreases the slope and increases the zero-point of the relation. Our results suggest a significant offset of the TFR zero-point between galaxies in low- and high-density environments, regardless of the kinematics estimator used. This can be interpreted as a decrease in either stellar mass by ~0.05-0.3dex or an increase in rotation velocity by ~0.02-0.06dex for galaxies in groups, depending on the samples used for comparison. We also studied the stellar and baryon mass fractions within stellar disks and found they both increase with stellar mass, the trend being more pronounced for the stellar component alone. These fractions do not exceed 50%. We show that this evolution of the TFR is consistent either with a decrease in star formation or with a contraction of the mass distribution due to the environment. These two effects probably act together, with their relative contribution depending on the mass regime.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/445/4073
- Title:
- Two catalogues of superclusters
- Short Name:
- J/MNRAS/445/4073
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present two new catalogues of superclusters of galaxies out to a redshift of z=0.15, based on the Abell/ACO cluster redshift compilation maintained by one of us (HA). The first of these catalogues, the all-sky Main SuperCluster Catalogue (MSCC), is based on only the rich (A-) Abell clusters, and the second one, the Southern SuperCluster Catalogue (SSCC), covers declinations {delta}<-17{deg} and includes the supplementary Abell S-clusters. A tunable Friends-of-Friends algorithm was used to account for the cluster density decreasing with redshift and for different selection functions in distinct areas of the sky. We present the full list of Abell clusters used, together with their redshifts and supercluster memberships and including the isolated clusters. The SSCC contains about twice the number of superclusters than MSCC for {delta}<-17{deg}, which we found to be due to (1) new superclusters formed by A-clusters in their cores and surrounded by S-clusters (50%), (2) new superclusters formed by S-clusters only (40%), (3) redistribution of member clusters by fragmentation of rich (multiplicity m>15) superclusters (8%), and (4) new superclusters formed by the connection of A-clusters through bridges of S-clusters (2%). Power-law fits to the cumulative supercluster multiplicity function yield slopes of {alpha}=-2.0 and {alpha}=-1.9 for MSCC and SSCC, respectively. This power-law behaviour is in agreement with the findings for other observational samples of superclusters, but not with that of catalogues based on cosmological simulations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/339/913
- Title:
- Two distant massive clusters of galaxies
- Short Name:
- J/MNRAS/339/913
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss the radio, optical, and X-ray properties of two newly discovered, very X-ray luminous, distant clusters of galaxies. Both systems were noted as cluster candidates in a cross-correlation of data from the WENSS (<VIII/162>) radio survey and the ROSAT All-Sky Survey (<IX/10>). Follow-up observations performed by us and the Massive Cluster Survey (MACS) team confirmed both sources as distant galaxy clusters. The first cluster, MACS J0717.5+3745 at a redshift of z=0.5548, contains a very extended, steep-spectrum radio source offset from the cluster core, making it the most distant radio relic known. The second cluster, MACS J1621.3+3810 at z=0.465, is a strong cooling flow with a relatively weak central radio source. We present results from ROSAT High-Resolution Imager (HRI, Cat. <IX/28>) observations of both clusters as well as from optical imaging and VLA radio interferometry observations. Our discoveries demonstrate that distant clusters can be efficiently identified in a relatively shallow X-ray survey, that radio/X-ray selection is efficient, and that both cooling flow and non-cooling flow clusters are selected.
- ID:
- ivo://CDS.VizieR/J/A+A/561/A111
- Title:
- U-band photometry of 17 WINGS clusters
- Short Name:
- J/A+A/561/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper belongs to a series presenting the WIde Field Nearby Galaxy-cluster Survey (WINGS). The WINGS project has collected wide-field, optical (B,V), and near-infrared (J,K) imaging as well as medium resolution spectroscopy of galaxies in a sample of 76 X-ray selected nearby clusters (0.04<z<0.07) with the aim of establishing a reference sample for evolutionary studies of galaxies and galaxy clusters. We present the U-band photometry of galaxies and stars in the fields of 17 clusters of the WINGS sample. We also extend the original B- and V-band photometry (WINGS-OPT) for 9 and 6 WINGS clusters to a larger field of view. We used both the new and already existing B-band photometry to obtain reliable (U-B) colors of galaxies within three fixed apertures in kpc. To this aim, we particular care the astrometric precision in the reduction procedure. Since not all the observations were taken in good transparency conditions, the photometric calibration was partly obtained by relying on the SDSS and WINGS-OPT photometry for the U- and optical bands, respectively. We provide U-band (also B- and V-band, where possible) total magnitudes of stars and galaxies in the fields of clusters. For galaxies only, the catalogs also provide geometrical parameters and carefully centered aperture magnitudes. The internal consistency of magnitudes was checked for clusters imaged with different cameras, while the external photometric consistency was obtained by comparison with the WINGS-OPT and SDSS surveys. The photometric catalogs presented here add the U-band information to the WINGS database for extending the spectral energy distribution (SED) of the galaxies, in particular in the ultraviolet (UV) wavelengths which are fundamental for deriving the star formation rate (SFR) properties.
- ID:
- ivo://CDS.VizieR/J/MNRAS/358/233
- Title:
- UBIc photometry of ACO2390 early-type galaxies
- Short Name:
- J/MNRAS/358/233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate a spectroscopic sample of 48 early-type galaxies in the rich cluster Abell 2390 at z=0.23 and 48 early-type galaxies from a previously published survey of Abell 2218 at z=0.18. The spectroscopic data of A2390 are based on multi-object spectroscopy using the multi-object spectrograph for Calar Alto at the 3.5-m telescope on Calar Alto Observatory and are complemented by ground-based imaging using the 5.1-m Hale telescope and Hubble Space Telescope (HST) observations in the F555W and F814W filters.
- ID:
- ivo://CDS.VizieR/J/A+A/592/A149
- Title:
- UBVI CCD photometry of Carina region stars
- Short Name:
- J/A+A/592/A149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Previous studies of the Carina region have revealed its complexity and richness as well as a significant number of early-type stars. However, in many cases, these studies only concentrated on the central region (Trumpler 14/16) or were not homogeneous. This latter aspect, in particular is crucial because very different ages and distances for key clusters have been claimed in recent years. The aim of this work is to study in detail an area of the Galactic plane in Carina, east ward Carina. We analyze the properties of different stellar populations and focus on a sample of open clusters and their population of young stellar objects and highly reddened early stars. We also studied the stellar mass distribution in these clusters and the possible scenario of their formation. Finally, we outline the Galactic spiral structure in this direction. We obtained deep and homogeneous photometric data (UBVIKC) for six young open clusters: NGC 3752, Trumpler 18, NGC 3590, Hogg 10, 11, and 12, located in Carina at l~291, and their adjacent stellar fields, which we complemented with spectroscopic observations of a few selected targets. We also culled additional information from the literature, which includes stellar spectral classifications and near-infrared photometry from 2MASS. We finally developed a numerical code that allowed us to perform a homogeneous and systematic analysis of the data. Our results provide more reliable estimates of distances, color excesses, masses, and ages of the stellar populations in this direction. We estimate the basic parameters of the studied clusters and find that they identify two overdensities of young stellar populations located at about 1.8kpc and 2.8kpc, with E_(B-V)_~0.1-0.6. We find evidence of pre-main-sequence populations inside them, with an apparent coeval stellar formation in the most conspicuous clusters. We also discuss apparent age and distance gradients in the direction NW-SE. We study the mass distributions of the covered clusters and several others in the region (which we took form the literature). They consistently show a canonical IMF slope (the Salpeter one). We discover and characterise an abnormally reddened massive stellar population, scattered between 6.6 and 11kpc. Spectroscopic observations of ten stars of this latter population show that all selected targets were massive OB stars. Their location is consistent with the position of the Carina-Sagittarius spiral arm.
- ID:
- ivo://CDS.VizieR/J/AJ/137/498
- Title:
- UCD and bright GC in Fornax
- Short Name:
- J/AJ/137/498
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- All the previously cataloged ultracompact dwarf (UCD) galaxies in the Fornax and Virgo clusters have 17.5<b_J_<20. Using the 2dF spectrograph on the Anglo-Australian Telescope, we have carried out a search for fainter UCDs in the Fornax Cluster. In the magnitude interval 19.5<b_J_<21.5, we have found 54 additional compact cluster members within a projected radius of 0.9{deg} (320kpc) of the cluster center, all of which meet our selection and observational criteria to be UCDs.
- ID:
- ivo://CDS.VizieR/J/ApJ/737/86
- Title:
- UCD galaxies in the Coma cluster
- Short Name:
- J/ApJ/737/86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have undertaken a spectroscopic search for ultra-compact dwarf galaxies (UCDs) in the dense core of the dynamically evolved, massive Coma cluster as part of the Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) Coma Cluster Treasury Survey. UCD candidates were initially chosen based on color, magnitude, degree of resolution within the ACS images, and the known properties of Fornax and Virgo UCDs. Follow-up spectroscopy with Keck/Low-Resolution Imaging Spectrometer confirmed 27 candidates as members of the Coma cluster, a success rate >60% for targeted objects brighter than M_R_=-12. Another 14 candidates may also prove to be Coma members, but low signal-to-noise spectra prevent definitive conclusions.
- ID:
- ivo://CDS.VizieR/J/A+A/528/A36
- Title:
- u*g'r'i' photometry of A496 faint LSB galaxies
- Short Name:
- J/A+A/528/A36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cluster faint low surface brightness galaxies (fLSBs) are difficult to observe. Consequently, their origin, physical properties and number density are not well known. After a first search for fLSBs in the highly substructured Coma cluster, we present here a search for fLSBs in the nearly relaxed Abell 496 cluster. Abell 496 appears to be a much more relaxed cluster than Coma, but still embedded in a large scale filament of galaxies. Our aim is to compare the properties of fLSBs in these two very different clusters, to search for environmental effects.
- ID:
- ivo://CDS.VizieR/J/MNRAS/475/4148
- Title:
- UKIDSS UDS field spectroscopic redshifts
- Short Name:
- J/MNRAS/475/4148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a large-scale galaxy structure Cl J021734-0513 at z~0.65 discovered in the UKIDSS UDS field, made of ~20 galaxy groups and clusters, spreading over 10Mpc. We report on a VLT/VIMOS spectroscopic follow-up program that, combined with past spectroscopy, allowed us to confirm four galaxy clusters (M_200_~10^14^M_{sun}_) and a dozen associated groups and star-forming galaxy overdensities. Two additional filamentary structures at z~0.62 and 0.69 and foreground and background clusters at 0.6<z<0.7 were also confirmed along the line of sight. The structure subcomponents are at different formation stages. The clusters have a core dominated by passive galaxies and an established red sequence. The remaining structures are a mix of star-forming galaxy overdensities and forming groups. The presence of quiescent galaxies in the core of the latter shows that 'pre-processing' has already happened before the groups fall into their more massive neighbours. Our spectroscopy allows us to derive spectral index measurements e.g. emission/absorption line equivalent widths, strength of the 4000{AA} break, valuable to investigate the star formation history of structure members. Based on these line measurements, we select a population of 'post-starburst' galaxies. These galaxies are preferentially found within the virial radius of clusters, supporting a scenario in which their recent quenching could be prompted by gas stripping by the dense intracluster medium. We derive stellar age estimates using Markov Chain Monte Carlo-based spectral fitting for quiescent galaxies and find a correlation between ages and colours/stellar masses which favours a top-down formation scenario of the red sequence. A catalogue of ~650 redshifts in UDS is released alongside the paper (via MNRAS online data).
