- ID:
- ivo://CDS.VizieR/J/ApJ/853/108
- Title:
- Clumpy galaxies in CANDELS. II. 0.5<=z<3.0
- Short Name:
- J/ApJ/853/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Studying giant star-forming clumps in distant galaxies is important to understand galaxy formation and evolution. At present, however, observers and theorists have not reached a consensus on whether the observed "clumps" in distant galaxies are the same phenomenon that is seen in simulations. In this paper, as a step to establish a benchmark of direct comparisons between observations and theories, we publish a sample of clumps constructed to represent the commonly observed "clumps" in the literature. This sample contains 3193 clumps detected from 1270 galaxies at 0.5<=z<3.0. The clumps are detected from rest-frame UV images, as described in our previous paper. Their physical properties (e.g., rest-frame color, stellar mass (M*), star formation rate (SFR), age, and dust extinction) are measured by fitting the spectral energy distribution (SED) to synthetic stellar population models. We carefully test the procedures of measuring clump properties, especially the method of subtracting background fluxes from the diffuse component of galaxies. With our fiducial background subtraction, we find a radial clump U-V color variation, where clumps close to galactic centers are redder than those in outskirts. The slope of the color gradient (clump color as a function of their galactocentric distance scaled by the semimajor axis of galaxies) changes with redshift and M* of the host galaxies: at a fixed M*, the slope becomes steeper toward low redshift, and at a fixed redshift, it becomes slightly steeper with M*. Based on our SED fitting, this observed color gradient can be explained by a combination of a negative age gradient, a negative E(B-V) gradient, and a positive specific SFR gradient of the clumps. We also find that the color gradients of clumps are steeper than those of intra-clump regions. Correspondingly, the radial gradients of the derived physical properties of clumps are different from those of the diffuse component or intra-clump regions.
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- ID:
- ivo://CDS.VizieR/J/AJ/126/2152
- Title:
- Cluster And Infall Region Nearby Survey. I
- Short Name:
- J/AJ/126/2152
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CAIRNS (Cluster and Infall Region Nearby Survey) project is a spectroscopic survey of the infall regions surrounding eight nearby, rich, X-ray-luminous clusters of galaxies. We have collected 15654 redshifts (3471 new or remeasured) within ~5-10h^-1^Mpc of the centers of the clusters, making it the largest study of the infall regions of clusters. We determine cluster membership and the mass profiles of the clusters based on the phase-space distribution of the galaxies. All of the clusters display decreasing velocity dispersion profiles. The mass profiles are fitted well by functional forms based on numerical simulations but exclude an isothermal sphere. Specifically, Navarro et al. (1997ApJ...490..493N) and Hernquist (1990ApJ...356..359H) models provide good descriptions of cluster mass profiles to their turnaround radii. Our sample shows that the predicted infall pattern is ubiquitous in rich, X-ray-luminous clusters over a large mass range. The caustic mass estimates are in excellent agreement with independent X-ray estimates at small radii and with virial estimates at intermediate radii. The mean ratio of the caustic mass to the X-ray mass is 1.03+/-0.11, and the mean ratio of the caustic mass to the virial mass (when corrected for the surface pressure term) is 0.93+/-0.07. We further demonstrate that the caustic technique provides reasonable mass estimates even in merging clusters.
- ID:
- ivo://CDS.VizieR/J/AJ/128/1078
- Title:
- Cluster and Infall Region Nearby Survey. II
- Short Name:
- J/AJ/128/1078
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CAIRNS (Cluster and Infall Region Nearby Survey) is a spectroscopic survey of the infall regions surrounding nine nearby rich clusters of galaxies. In our previous paper (Cat. <J/AJ/126/2152>), we used redshifts within ~10h_-1_ Mpc of the centers of the clusters to determine the mass profiles of the clusters based on the phase-space distribution of the galaxies. Here, we use Two Micron All Sky Survey (Cat. <II/246>) photometry and an additional 515 redshifts to investigate the environmental dependence of near-infrared mass-to-light ratios.
- ID:
- ivo://CDS.VizieR/J/AJ/133/2222
- Title:
- Clustering of high-redshift QSOs from SDSS
- Short Name:
- J/AJ/133/2222
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the two-point correlation function of a uniformly selected sample of 4426 luminous optical quasars with redshift 2.9<=z<=5.4 selected over 4041deg^2^ from the Fifth Data Release of the Sloan Digital Sky Survey. We fit a power-law to the projected correlation function w_p_(r_p_) to marginalize over redshift-space distortions and redshift errors.
- ID:
- ivo://CDS.VizieR/J/A+A/637/A31
- Title:
- Cluster in superclusters of galaxies
- Short Name:
- J/A+A/637/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The characterization of the internal structure of the superclusters of galaxies (walls, filaments and knots where the clusters are located) is paramount for understanding the formation of the Large Scale Structure and for outlining the environment where galaxies evolved in the last Gyr. (i) To detect the compact regions of high relative density (clusters and rich groups of galaxies); (ii) to map the elongated structures of low relative density (filaments, bridges and tendrils of galaxies); (iii) to characterize the galaxy populations on filaments and study the environmental effects they are subject to. We employed optical galaxies with spectroscopic redshifts from the SDSS-DR13 inside rectangular boxes encompassing the volumes of a sample of 46 superclusters of galaxies, up to z=0.15. A virial approximation was applied to correct the positions of the galaxies in the redshift space for the "finger of God" projection effect. Our methodology implements different classical pattern recognition and machine learning techniques (Voronoi tessellation, hierarchical clustering, graph-network theory, minimum spanning trees, among others), pipelined in the Galaxy Systems-Finding algorithm and the Galaxy Filaments-Finding algorithm. We detected in total 2705 galaxy systems (clusters and groups, of which 159 are new) and 144 galaxy filaments in the 46 superclusters of galaxies. The filaments we detected have a density contrast above 3, with a mean value around 10, a radius of about 2.5h_70_^-1^Mpc and lengths between 9 and 130h_70_^-1^Mpc. Correlations between the galaxy properties (mass, morphology and activity) and the environment in which they reside (systems, filaments and the dispersed component) suggest that galaxies closer to the skeleton of the filaments are more massive by up to 25% compared to those in the dispersed component; 70% of the galaxies in the filament region present early type morphologies and the fractions of active galaxies (both AGN and SF) seem to decrease as galaxies approach the filament. Our results support thee idea that galaxies in filaments are subject to environmental effects leading them to be more massive (probably due to larger rates of both merging and gas accretion), less active both in star formation and nuclear activity, and prone to the density-morphology relation. These results suggest that preprocessing in large scale filaments could have significant effects on galaxy evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/616/A42
- Title:
- Clusters candidates from PSZ1 catalogue
- Short Name:
- J/A+A/616/A42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified new clusters and characterized previously unknown Planck Sunyaev-Zeldovich (SZ) sources from the first Planck catalogue of SZ sources (PSZ1). The results presented here correspond to an optical follow-up observational programme developed during approximately one year (2014) at Roque de los Muchachos Observatory, using the 2.5m Isaac Newton telescope, the 3.5m Telescopio Nazionale Galileo, the 4.2m William Herschel telescope and the 10.4m Gran Telescopio Canarias. We have characterized 115 new PSZ1 sources using deep optical imaging and spectroscopy. We adopted robust criteria in order to consolidate the SZ counterparts by analysing the optical richness, the 2D galaxy distribution, and velocity dispersions of clusters. Confirmed counterparts are considered to be validated if they are rich structures, well aligned with the Planck PSZ1 coordinate and show relatively high velocity dispersion. Following this classification, we confirm 53 clusters, which means that 46% of this PSZ1 subsample has been validated and characterized with this technique. Sixty-two SZ sources (54% of this PSZ1 subset) remain unconfirmed. In addition, we find that the fraction of unconfirmed clusters close to the galactic plane (at |b|<25{deg}) is greater than that at higher galactic latitudes (|b|>25{deg}), which indicates contamination produced by radio emission of galactic dust and gas clouds on these SZ detections. In fact, in the majority of the cases, we detect important galactic cirrus in the optical images, mainly in the SZ target located at low galactic latitudes, which supports this hypothesis.
- ID:
- ivo://CDS.VizieR/J/ApJS/199/34
- Title:
- Clusters of galaxies in SDSS-III
- Short Name:
- J/ApJS/199/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the photometric redshifts of galaxies from the Sloan Digital Sky Survey III (SDSS-III), we identify 132684 clusters in the redshift range of 0.05<=z<0.8. Monte Carlo simulations show that the false detection rate is less than 6% for the whole sample. The completeness is more than 95% for clusters with a mass of M_200_>1.0x10^14^M_{sun}_ in the redshift range of 0.05<=z<0.42, while clusters of z>0.42 are less complete and have a biased smaller richness than the real one due to incompleteness of member galaxies. We compare our sample with other cluster samples, and find that more than 90% of previously known rich clusters of 0.05<=z<0.42 are matched with clusters in our sample. Richer clusters tend to have more luminous brightest cluster galaxies (BCGs). Correlating with X-ray and the Planck data, we show that the cluster richness is closely related to the X-ray luminosity, temperature, and Sunyaev-Zel'dovich measurements. Comparison of the BCGs with the SDSS luminous red galaxy (LRG) sample shows that 25% of LRGs are BCGs of our clusters and 36% of LRGs are cluster member galaxies. In our cluster sample, 63% of BCGs of r_petro_<19.5 satisfy the SDSS LRG selection criteria.
- ID:
- ivo://CDS.VizieR/J/A+A/628/A28
- Title:
- 3C 294 NIR images and optical spectra
- Short Name:
- J/A+A/628/A28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High redshift radio galaxies are among the most massive galaxies at their redshift, are often found in the centers of proto-clusters of galaxies, and are expected to evolve into the present day massive central cluster galaxies. Thus they are a useful tool to explore structure formation in the young Universe. 3C 294 is a powerful FR II type radio galaxy at z=1.786. Past studies have identified a clumpy structure, possibly indicative of a merging system, as well as tentative evidence that 3C 294 hosts a dual AGN. Due to its proximity to a bright star, it was subject to various adaptive optics imaging studies. In order to distinguish between the various scenarios for 3C 294 we performed deep high-resolution adaptive optics imaging and optical spectroscopy of 3C 294 with the Large Binocular Telescope. We resolve the 3C 294 system into three distinct components separated by a few tenths of an arcsecond on our images. One is compact, the other two are extended, all appear to be non-stellar. The nature of each component is unclear. The latter could be a galaxy with an internal absorption feature, a galaxy merger or two galaxies at different redshifts. We can now uniquely associate the radio source of 3C 294 with one of the extended components. Based on our spectroscopy, we determined a redshift of z=1.784+/-0.001, which is similar to the one previously cited. In addition we found a previously unreported emission line at lambda 6749.4{AA} in our spectra. It is not clear that it originates from 3C 294. It could be the Ne [IV] doublet lambda 2424/2426{AA} at z=1.783, or belong to the compact component at a redshift of z~4.56. We thus can not unambiguously determine whether 3C 294 hosts a dual AGN or a projected pair of AGNs.
- ID:
- ivo://CDS.VizieR/J/ApJS/102/289
- Title:
- CNOC cluster redshift survey catalogs. II.
- Short Name:
- J/ApJS/102/289
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A photometric and redshift catalog of galaxies in the field of the rich galaxy cluster Abell 2390 (z=0.228) is presented as part of the Canadian Network for Observation Cosmology (CNOC) cluster redshift survey carried out at the Canada-France-Hawaii Telescope (CFHT) using the MOS imaging multiobject spectrograph. Using five separate fields, the imaging and spectroscopic observations cover a strip of approximately 7.3'x43.2', centered on the cluster. Redshifts for 327 galaxies, primarily ranging in magnitude from r=17 to 22, were obtained. The data set is also presented graphically in several forms. The magnitude, geometric, and color selection functions for the redshift sample are discussed and presented.
- ID:
- ivo://CDS.VizieR/J/ApJS/113/1
- Title:
- CNOC cluster redshift survey catalogs. III.
- Short Name:
- J/ApJS/113/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A photometric and redshift catalog of galaxies in the field of two rich galaxy clusters, MS 1621.5+2640 (z=0.4275) and MS 0302.7+1658 (z=0.4245), is presented as part of the Canadian Network for Observation Cosmology (CNOC) Cluster Redshift Survey carried out at the Canada-France-Hawaii Telescope (CFHT) using the MOS imaging multiobject spectrograph. The imaging and spectroscopic observations cover strips cantered on each cluster of approximately 23.3'x9.0', and 7.9'x9.0', for MS 1621.5+2640 and MS 0302.7+1658, respectively. Redshifts for 371 galaxies, primarily ranging in magnitude from r=20 to 22, were obtained. The data set is also presented graphically in several forms. The magnitude, color, and geometric selection functions for the redshift sample are presented and discussed.
