- ID:
- ivo://CDS.VizieR/J/ApJ/843/76
- Title:
- Cool-core clusters with Chandra obs.
- Short Name:
- J/ApJ/843/76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive and compare the fractions of cool-core clusters in the Planck Early Sunyaev-Zel'dovich sample of 164 clusters with z<=0.35 and in a flux- limited X-ray sample of 100 clusters with z<=0.30, using Chandra observations. We use four metrics to identify cool-core clusters: (1) the concentration parameter, which is the ratio of the integrated emissivity profile within 0.15 r_500_ to that within r_500_; (2) the ratio of the integrated emissivity profile within 40kpc to that within 400kpc; (3) the cuspiness of the gas density profile, which is the negative of the logarithmic derivative of the gas density with respect to the radius, measured at 0.04 r_500_; and (4) the central gas density, measured at 0.01 r_500_. We find that the sample of X-ray-selected clusters, as characterized by each of these metrics, contains a significantly larger fraction of cool-core clusters compared to the sample of SZ-selected clusters (44%+/-7% versus 28%+/-4% using the concentration parameter in the 0.15-1.0 r_500_ range, 61%+/-8% versus 36%+/-5% using the concentration parameter in the 40-400 kpc range, 64%+/-8% versus 38%+/-5% using the cuspiness, and 53%+/-7% versus 39+/-5% using the central gas density). Qualitatively, cool-core clusters are more X-ray luminous at fixed mass. Hence, our X-ray, flux-limited sample, compared to the approximately mass-limited SZ sample, is overrepresented with cool-core clusters. We describe a simple quantitative model that uses the excess luminosity of cool-core clusters compared to non-cool-core clusters at fixed mass to successfully predict the observed fraction of cool-core clusters in X-ray-selected samples.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/292/419
- Title:
- Cooling flows in 207 clusters of galaxies
- Short Name:
- J/MNRAS/292/419
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present an X-ray image deprojection analysis of Einstein Observatory imaging data on 207 clusters of galaxies. The resulting radial profiles for luminosity, temperature and electron density variations are determined from the cluster surface-brightness profiles according to gravitational potential constraints from average X-ray temperatures and optical velocity dispersions. This enables us to determine cooling flow and other cluster properties, such as baryon fractions, Sunyaev-Zel'dovich microwave decrements and Thomson depths. From the results we have compiled a catalogue of the detected cooling flows, and investigated their effects on general cluster properties.
- ID:
- ivo://CDS.VizieR/J/AJ/130/2541
- Title:
- Core of the Shapley supercluster at 1.4GHz
- Short Name:
- J/AJ/130/2541
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The core of the Shapley supercluster (A3556, A3558, SC 1327-312, SC 1329-313, and A3562) is an ideal region in which to study the effects of cluster mergers on the activity of individual galaxies. This paper presents the most comprehensive radio continuum investigation of the region, relying on a 63 pointing mosaic obtained with the Very Large Array yielding an areal coverage of nearly 7{deg}^2^.
- ID:
- ivo://CDS.VizieR/J/AJ/152/50
- Title:
- Cosmicflows-3 catalog (CF3)
- Short Name:
- J/AJ/152/50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Cosmicflows database of galaxy distances that in the second edition contained 8188 entries is now expanded to 17669 entries. The major additions are 2257 distances that we have derived from the correlation between galaxy rotation and luminosity with photometry at 3.6{mu}m obtained with the Spitzer Space Telescope and 8885 distances based on the Fundamental Plane methodology from the Six Degree Field Galaxy Survey collaboration. There are minor augmentations to the Tip of the Red Giant Branch and Type Ia supernova compilations. A zero-point calibration of the supernova luminosities gives a value for the Hubble Constant of 76.2+/-3.4+/-2.7 (+/-rand.+/-sys.)km/s/Mpc. Alternatively, a restriction on the peculiar velocity monopole term representing global infall/outflow implies H_0_=75+/-2km/s/Mpc.
- ID:
- ivo://CDS.VizieR/J/ApJ/896/3
- Title:
- Cosmicflows-4: Tully-Fisher relation calibrations
- Short Name:
- J/ApJ/896/3
- Date:
- 07 Mar 2022 07:21:25
- Publisher:
- CDS
- Description:
- This study is a part of the Cosmicflows-4 project with the aim of measuring the distances of more than ~10000 spiral galaxies in the local universe up to ~15000km/s. New HI line width information has come primarily from the Arecibo Legacy Fast ALFA Survey. Photometry of our sample galaxies has been carried out in optical (SDSS u, g, r, i, and z) and infrared (WISE W1 and W2) bands. Inclinations have been determined using an online graphical interface accessible to a collaboration of citizen scientists. Galaxy distances are measured based on the correlation between the rotation rate of spirals and their absolute luminosity, known as the Tully-Fisher relation (TFR). In this study, we present the calibration of the TFR using a subsample of ~600 spirals located in 20 galaxy clusters. Correlations among such observables as color, surface brightness, and relative HI content are explored in an attempt to reduce the scatter about the TFR with the goal of obtaining more accurate distances. A preliminary determination of the Hubble constant from the distances and velocities of the calibrator clusters is H0=76.0+/-1.1(stat.)+/-2.3(sys.)km/s/Mpc.
- ID:
- ivo://CDS.VizieR/J/MNRAS/438/3465
- Title:
- Cosmic web filaments in the SDSS
- Short Name:
- J/MNRAS/438/3465
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The main feature of the spatial large-scale galaxy distribution is its intricate network of galaxy filaments. This network is spanned by the galaxy locations that can be interpreted as a three-dimensional point distribution. The global properties of the point process can be measured by different statistical methods, which, however, do not describe directly the structure elements. The morphology of the large scale structure, on the other hand, is an important property of the galaxy distribution. Here we apply an object point process with interactions (the Bisous model) to trace and extract the filamentary network in the presently largest galaxy redshift survey, the Sloan Digital Sky Survey (SDSS). We search for filaments in the galaxy distribution that have a radius of about 0.5Mpc/h. We divide the detected network into single filaments and present a public catalogue of filaments. We study the filament length distribution and show that the longest filaments reach the length of 60Mpc/h. The filaments contain 35-40% of the total galaxy luminosity and they cover roughly 5-8% of the total volume, in good agreement with N-body simulations and previous observational results.
- ID:
- ivo://CDS.VizieR/J/A+A/590/A27
- Title:
- CO spectra of Virgo cluster galaxies
- Short Name:
- J/A+A/590/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ^12^CO(1-0) and ^12^CO(2-1) observations of a sample of 20 star-forming dwarfs selected from the Herschel Virgo Cluster Survey, with oxygen abundances ranging from 12+log(O/H)~8.1 to 8.8. CO emission is observed in ten galaxies and marginally detected in another one. CO fluxes correlate with the FIR 250um emission, and the dwarfs follow the same linear relation that holds for more massive spiral galaxies extended to a wider dynamical range. We compare different methods to estimate H_2_ molecular masses, namely a metallicity-dependent CO-to-H_2_ conversion factor and one dependent on H-band luminosity. The molecular-to-stellar mass ratio remains nearly constant at stellar masses <=10^9^M_{sun}_, contrary to the atomic hydrogen fraction, M_HI_/M*, which increases inversely with M*. The flattening of the M_H2_/M* ratio at low stellar masses does not seem to be related to the effects of the cluster environment because it occurs for both HI-deficient and HI-normal dwarfs. The molecular-to-atomic ratio is more tightly correlated with stellar surface density than metallicity, confirming that the interstellar gas pressure plays a key role in determining the balance between the two gaseous components of the interstellar medium. Virgo dwarfs follow the same linear trend between molecular gas mass and star formation rate as more massive spirals, but gas depletion timescales, tau_dep, are not constant and range between 100Myr and 6Gyr. The interaction with the Virgo cluster environment is removing the atomic gas and dust components of the dwarfs, but the molecular gas appears to be less affected at the current stage of evolution within the cluster. However, the correlation between HI deficiency and the molecular gas depletion time suggests that the lack of gas replenishment from the outer regions of the disc is lowering the star formation activity.
- ID:
- ivo://CDS.VizieR/VII/201
- Title:
- Cross-Identifications in Abell and Zwicky clusters
- Short Name:
- VII/201
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new identification between Abell and Zwicky clusters of galaxies and vice versa is completed. Two convenient files are generated with necessary data for comparing both catalogs; remarks on the cluster matching are also included.
- ID:
- ivo://CDS.VizieR/J/A+AS/127/463
- Title:
- Crux region redshifts
- Short Name:
- J/A+AS/127/463
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In our systematic optical galaxy search behind the southern Milky Way, 3760 (mostly unknown) galaxies with diameters D>0.2' were identified in the Crux region (287{deg}<~l<~318{deg}, |b|<~10{deg}, Woudt & Kraan-Korteweg 1998, in press). Prior to this investigation, only 65 of these galaxies had known redshifts. In order to map the galaxy distribution in redshift space we obtained spectra for 226 bright (B_J_<~18.0mag) objects with the 1.9m telescope of the South African Astronomical Observatory (SAAO). Redshifts could be determined for 209 objects, of which 173 have good signal-to-noise ratios. Of the 36 tentative redshifts, four are confirmed through independent values in the literature. The redshifts of three objects indicate them to be galactic in origin. One of these confirms a suspected Planetary Nebula. For 17 of the galaxies, no redshift could be determined due to poor signal-to-noise ratios. In addition, 26 redshifts have have been measured in the Hydra-Antlia region investigated earlier (Kraan-Korteweg et al., 1995, Cat. <J/A+A/297/617>), of which one is a tentative estimate. Two main structures crossing the Galactic Plane in the Crux region have now become clear. A narrow, nearby filament from (l, b)=(340{deg}, -25{deg}) to the Centaurus cluster can be traced. This filament runs almost parallel to the extension of the Hydra-Antlia clusters found earlier and is part of what we have earlier termed the ``Centaurus Wall'' extending in redshift-space between 0<=v<=6000km/s (Fairall & Paverd 1995, in Wide-Field Spedctroscopy and the Distant Universe, p. 121). The main outcome of this survey however, is the recognition of another massive extended structure between 4000<=v<=8000km/s. This broad structure, dubbed the Norma Supercluster (Woudt et al. 1997, in press), runs nearly parallel to the Galactic Plane from Vela to ACO 3627 (its centre) from where it continues to the Pavo cluster. This massive structure is believed to be associated with the Great Attractor. The survey has furthermore revealed a set of cellular structures, similar to those seen in redshift space at higher galactic latitudes, but never before seen so clearly behind the Milky Way.
- ID:
- ivo://CDS.VizieR/J/MNRAS/367/156
- Title:
- C-T1 photometry in NGC 1374, 1379 and 1387
- Short Name:
- J/MNRAS/367/156
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric study of the globular cluster systems (GCSs) of the Fornax cluster galaxies NGC 1374, NGC 1379 and NGC 1387. The data consist of images from the wide-field MOSAIC imager of the Cerro Tololo Inter-American Observatory (CTIO) 4-m telescope, obtained with Washington C and Kron-Cousins R filters. The images cover a field of 36x36arcmin^2^, corresponding to 200x200kpc^2^ at the Fornax distance. Two of the galaxies, NGC 1374 and NGC 1379, are low-luminosity ellipticals while NGC 1387 is a low-luminosity lenticular. Their cluster systems are still embedded in the cluster system of NGC 1399. Therefore, the use of a large field is crucial and some differences to previous work can be explained by this. The colour distributions of all GCSs are bimodal. NGC 1387 presents a particularly distinct separation between red and blue clusters and an over-proportionally large population of red clusters. The radial distribution is different for blue and red clusters, red clusters being more concentrated towards the respective galaxies. The different colour and radial distributions point to the existence of two globular cluster subpopulations in these galaxies. Specific frequencies are in the range S_N_=1.4-2.4, smaller than the typical values for elliptical galaxies. These galaxies might have suffered tidal stripping of blue globular clusters by NGC 1399.
