- ID:
- ivo://CDS.VizieR/J/ApJ/890/148
- Title:
- Concentration-mass relation for XXL clusters
- Short Name:
- J/ApJ/890/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a weak-lensing analysis of X-ray galaxy groups and clusters selected from the XMM-XXL survey using the first-year data from the Hyper Suprime-Cam (HSC) Subaru Strategic Program. Our joint weak-lensing and X-ray analysis focuses on 136 spectroscopically confirmed X-ray-selected systems at 0.031<=z<=1.033 detected in the 25deg^2^ XXL-N region, which largely overlaps with the HSC-XMM field. With high-quality HSC weak-lensing data, we characterize the mass distributions of individual clusters and establish the concentration-mass (c-M) relation for the XXL sample, by accounting for selection bias and statistical effects and marginalizing over the remaining mass calibration uncertainty. We find the mass-trend parameter of the c-M relation to be {beta}=-0.07+/-0.28 and the normalization to be c_200_=4.8+/-1.0(stat)+/-0.8(syst) at M_200_=10^14^h^-1^M_{sun}_ and z=0.3. We find no statistical evidence for redshift evolution. Our weak-lensing results are in excellent agreement with dark-matter-only c-M relations calibrated for recent {Lambda}CDM cosmologies. The level of intrinsic scatter in c200 is constrained as {sigma}(lnc_200_)<24% (99.7% CL), which is smaller than predicted for the full population of {Lambda}CDM halos. This is likely caused in part by the X-ray selection bias in terms of the cool-core or relaxation state. We determine the temperature-mass (T_X_-M_500_) relation for a subset of 105 XXL clusters that have both measured HSC lensing masses and X-ray temperatures. The resulting TX-M500 relation is consistent with the self-similar prediction. Our TX-M500 relation agrees with the XXL DR1 results at group scales but has a slightly steeper mass trend, implying a smaller mass scale in the cluster regime. The overall offset in the TX-M500 relation is at the ~1.5{sigma} level, corresponding to a mean mass offset of 34%+/-20%. We also provide bias-corrected, weak-lensing-calibrated M200 and M500 mass estimates of individual XXL clusters based on their measured X-ray temperatures.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/468/1917
- Title:
- Concentration parameter of galaxy clusters
- Short Name:
- J/MNRAS/468/1917
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We characterized the population of galaxy clusters detected with the Sunyaev-Zeldovich (SZ) effect with Planck by measuring the cool-core state of the objects in a well-defined subsample of the Planck SZ catalogue. We used as an indicator the concentration parameter. The fraction of cool-core clusters is 29+/-4 per cent and does not show significant indications of evolution in the redshift range covered by our sample. We compare the distribution of the concentration parameter in the Planck sample with the one of the X-ray selected sample MACS: the distributions are significantly different and the cool-core fraction in MACS is much higher (59+/-5 per cent) than that in Planck. Since X-ray-selected samples are known to be biased towards cool cores due to the presence of their prominent surface brightness peak, we simulated the impact of the 'cool-core bias'. We found that this bias plays a large role in the difference between the fractions of cool cores in the two samples. We examined other selection effects that could in principle bias SZ surveys against cool cores, but we found that their impact is not sufficient to explain the difference between Planck and MACS. The population of X-ray underluminous objects, which are found in SZ surveys but missing in X-ray samples, could possibly contribute to the difference, as we found most of them to be non-cool cores, but this hypothesis deserves further investigation.
- ID:
- ivo://CDS.VizieR/J/ApJ/725/1252
- Title:
- Confirmed members of RX J0152.7-1357
- Short Name:
- J/ApJ/725/1252
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectrophotometric analysis of galaxies belonging to the dynamically young, massive cluster RX J0152.7-1357 at z~0.84, aimed at understanding the effects of the cluster environment on the star formation history (SFH) of cluster galaxies and the assembly of the red sequence (RS). We use VLT/FORS spectroscopy, ACS/WFC optical, and NTT/SofI near-IR data to characterize SFHs as a function of color, luminosity, morphology, stellar mass, and local environment from a sample of 134 spectroscopic members. In order to increase the signal-to-noise ratio, individual galaxy spectra are stacked according to these properties. Moreover, the D4000, Balmer, CN3883, Fe4383, and C4668 indices are also quantified.
- ID:
- ivo://CDS.VizieR/J/A+A/620/A111
- Title:
- Confirmed PN in M87 outer regions
- Short Name:
- J/A+A/620/A111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a kinematic study of a sample of 298 planetary nebulas (PNs) in the outer halo of the central Virgo galaxy M87 (NGC 4486). The line-of-sight velocities of these PNs are used to identify sub-components, to measure the angular momentum content of the main M87 halo, and to constrain the orbital distribution of the stars at these large radii. We use Gaussian mixture modelling to statistically separate distinct velocity components and identify the M87 smooth halo component, its unrelaxed substructures, and the intra-cluster (IC) PNs. We compute probability weighted velocity and velocity dispersion maps for the smooth halo, and its specific angular momentum profile ({lambda}_R_) and velocity dispersion profile. The classification of the PNs into smooth halo and ICPNs is supported by their different PN luminosity functions. Based on a K-S test, we conclude that the ICPN line-of-sight velocity distribution (LOSVD) is consistent with the LOSVD of the galaxies in Virgo subcluster A. The surface density profile of the ICPNS at 100kpc radii has a shallow logarithmic slope, -{alpha}_ICL_~=-0.8, dominating the light at the largest radii. Previous B-V colour and resolved star metallicity data indicate masses for the ICPN progenitor galaxies of a few x10^8^M_{sun}_. The angular momentum-related {lambda}_R_ profile for the smooth halo remains below 0.1, in the slow rotator regime, out to 135kpc average ellipse radius (170kpc major axis distance). Combining the PN velocity dispersion measurements for the M87 halo with literature data in the central 15kpc, we obtain a complete velocity dispersion profile out to R_avg_=135kpc. The {sigma}_halo_ profile decreases from the central 400km/s to about 270km/s at 2-10kpc, then rises again to ~=300+/-50km/s at 50-70kpc to finally decrease sharply to {sigma}_halo_~100km/s at R_avg_=135kpc. The steeply decreasing outer {sigma}_halo_ profile and the surface density profile of the smooth halo can be reconciled with the circular velocity curve inferred from assuming hydrostatic equilibrium for the hot X-ray gas. Because this rises to v_c,X_~700km/s at 200kpc, the orbit distribution of the smooth M87 halo is required to change strongly from approximately isotropic within R_avg_~60kpc to very radially anisotropic at the largest distances probed. The extended LOSVD of the PNs in the M87 halo allows the identification of several subcomponents: the ICPNs, the "crown" accretion event, and the smooth M87 halo. In galaxies likeM87, the presence of these sub-components needs to be taken into account to avoid systematic biases in estimating the total enclosed mass. The dynamical structure inferred from the velocity dispersion profile indicates that the smooth halo of M87 steepens beyond Ravg=60kpc and becomes strongly radially anisotropic, and that the velocity dispersion profile is consistent with the X-ray circular velocity curve at these radii without non-thermal pressure effects.
- ID:
- ivo://CDS.VizieR/J/A+A/558/A60
- Title:
- CO(2-1) observations of central AGN at z=1.4
- Short Name:
- J/A+A/558/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The formation of the first virialized structures in overdensities dates back to ~9Gyr ago, i.e. in the redshift range z~1.4-1.6. Some models of structure formation predict that the star formation activity in clusters was high at that epoch, implying large reservoirs of cold molecular gas. Aiming at finding a trace of this expected high molecular gas content in primeval clusters, we searched for the ^12^CO(2-1) line emission in the most luminous active galactic nucleus (AGN) of the cluster around the radio galaxy 7C 1756+6520 at z~1.4, one of the farthest spectroscopic confirmed clusters. This AGN, called AGN.1317, is located in the neighbourhood of the central radio galaxy at a projected distance of ~780 kpc. The IRAM Plateau de Bure Interferometer was used to investigate the molecular gas quantity in AGN.1317, observing the ^12^CO(2-1) emission line. We detect CO emission in an AGN belonging to a galaxy cluster at z~1.4. We measured a molecular gas mass of 1.1x10^10^M_{sun}_, comparable to that found in submillimeter galaxies. In optical images, AGN.1317 does not seem to be part of a galaxy interaction or merger. We also derived the nearly instantaneous star formation rate (SFR) from Halpha flux obtaining a SFR~65M_{sun}_/yr. This suggests that AGN.1317 is actively forming stars and will exhaust its reservoir of cold gas in ~0.2-1.0Gyr.
- 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.
- 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.
