- 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.
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Search 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.
- ID:
- ivo://CDS.VizieR/J/MNRAS/386/2311
- Title:
- CT1 photometry of Antlia early-type galaxies
- Short Name:
- J/MNRAS/386/2311
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first colour-magnitude relation (CMR) of early-type galaxies in the central region of the Antlia cluster, obtained from CCD wide-field photometry in the Washington photometric system. Integrated (C-T1) colours, T1 magnitudes, and effective radii have been measured for 93 galaxies (i.e. the largest galaxies sample in the Washington system till now) from the FS90 Antlia Group catalogue. Membership of 37 objects can be confirmed through new radial velocities and data collected from the literature.
- ID:
- ivo://CDS.VizieR/J/MNRAS/425/477
- Title:
- Dark matter annihilation in galaxy clusters
- Short Name:
- J/MNRAS/425/477
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Clusters of galaxies are potentially important targets for indirect searches for dark matter (DM) annihilation. Here we reassess the detection prospects for annihilation in massive haloes, based on a statistical investigation of 1743 clusters in the new Meta-Catalogue of X-ray Clusters (MCXC). We derive a new limit for the extragalactic DM annihilation background of at least 20 per cent of that originating from the Galaxy for an integration angle of 0.1{deg}.
- ID:
- ivo://CDS.VizieR/VII/87A
- Title:
- Data on 1889 Abell's clusters of galaxies
- Short Name:
- VII/87A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A sample of 1889 clusters from Abell's catalogue of Rich Clusters of Galaxies (1958, ApJS 3, 211) have been classified in the Bautz-Morgan system
- ID:
- ivo://CDS.VizieR/J/A+A/546/A79
- Title:
- 400d Cluster Survey Weak Lensing Programme II
- Short Name:
- J/A+A/546/A79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Evolution in the mass function of galaxy clusters sensitively traces both the expansion history of the Universe and cosmological structure formation. Robust cluster mass determinations are a key ingredient for a reliable measurement of this evolution, especially at high redshift. Weak gravitational lensing is a promising tool for, on average, unbiased mass estimates. This weak lensing project aims at measuring reliable weak lensing masses for a complete X-ray selected sample of 36 high redshift (0.35<z<0.9) clusters. The goal of this paper is to demonstrate the robustness of the methodology against commonly encountered problems, including pure instrumental effects, the presence of bright (8-9mag) stars close to the cluster centre, ground based measurements of high-z (z~0.8) clusters, and the presence of massive unrelated structures along the line-sight.
- ID:
- ivo://CDS.VizieR/J/A+A/617/A64
- Title:
- 3D density & temp. profiles of 5 clusters
- Short Name:
- J/A+A/617/A64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed study of the integrated total hydrostatic mass profiles of the five most massive (M_500_^SZ^>5x10^14^M_{sun}_) galaxy 500 clusters selected at z~1 via the Sunyaev-Zel'dovich effect. These objects represent an ideal laboratory to test structure formation models where the primary driver is gravity. Optimally exploiting spatially-resolved spectroscopic information from XMM-Newton and Chandra observations, we used both parametric (forward, backward) and non-parametric methods to recover the mass profiles, finding that the results are extremely robust when density and temperature measurements are both available. Our X-ray masses at R_500_ are higher than the weak lensing masses obtained from the Hubble Space Telescope (HST), with a mean ratio of 1.39^+0.47^_-0.35_. This offset goes in the opposite direction to that expected in a scenario where the hydrostatic method yields a biased, underestimated, mass. We investigated halo shape parameters such as sparsity and concentration, and compared to local X-ray selected clusters, finding hints for evolution in the central regions (or for selection effects). The total baryonic content is in agreement with the cosmic value at R_500_. Comparison with numerical simulations shows that the mass distribution and concentration are in line with expectations. These results illustrate the power of X-ray observations to probe the statistical properties of the gas and total mass profiles in this high-mass, high-redshift regime.
