- ID:
- ivo://CDS.VizieR/J/A+A/607/A81
- Title:
- Properties of the sample of clusters
- Short Name:
- J/A+A/607/A81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The relation between a cosmological halo concentration and its mass (cMr) is a powerful tool to constrain cosmological models of halo formation and evolution. On the scale of galaxy clusters the cMr has so far been determined mostly with X-ray and gravitational lensing data. The use of independent techniques is helpful in assessing possible systematics. Here we provide one of the few determinations of the cMr by the dynamical analysis of the projected-phase-space distribution of cluster members. Based on the WINGS and OmegaWINGS data sets, we used the Jeans analysis with the MAMPOSSt technique to determine masses and concentrations for 49 nearby clusters, each of which has >~60 spectroscopic members within the virial region, after removal of substructures. Our cMr is in statistical agreement with theoretical predictions based on {LAMBDA}CDM cosmological simulations. Our cMr is different from most previous observational determinations because of its flatter slope and lower normalization. It is however in agreement with two recent cMr obtained using the lensing technique on the CLASH and LoCuSS cluster data sets. The dynamical study of the projected-phase-space of cluster members is an independent and valid technique to determine the cMr of galaxy clusters. Our cMr shows no tension with theoretical predictions from {LAMBDA}CDM cosmological simulations for low-redshift, massive galaxy clusters. In the future we will extend our analysis to galaxy systems of lower mass and at higher redshifts.
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- ID:
- ivo://CDS.VizieR/J/A+A/655/A115
- Title:
- PSZ1 galaxy clusters {sigma} and Mdyn
- Short Name:
- J/A+A/655/A115
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present the velocity dispersion and dynamical mass estimates for 270 galaxy clusters included in the first Planck Sunyaev-Zeldovich (SZ) source catalogue, the PSZ1. Part of the results presented here were achieved during a two-year observational program, the ITP, developed at the Roque de los Muchachos Observatory (La Palma, Spain). In the ITP we carried out a systematic optical follow-up campaign of all the 212 unidentified PSZ1 sources in the northern sky that have a declination above -15{deg} and are without known counterparts at the time of the publication of the catalogue. We present for the first time the velocity dispersion and dynamical mass of 58 of these ITP PSZ1 clusters, plus 35 newly discovered clusters that are not associated with the PSZ1 catalogue. Using Sloan Digital Sky Survey archival data, we extend this sample, including 212 already confirmed PSZ1 clusters in the northern sky. Using a subset of 207 of these galaxy clusters, we constrained the M_SZ_-M_dyn_ scaling relation, finding a mass bias of (1-B)=0/83+/-0.07(stat)+/-0.02(sys). We show that this value is consistent with other results in the literature that were obtained with different methods (X-ray, dynamical masses, or weak-lensing mass proxies). This result cannot dissolve the tension between primordial cosmic microwave background anisotropies and cluster number counts in the {OMEGA}_M_-{sigma}8 plane.
- ID:
- ivo://CDS.VizieR/J/MNRAS/391/1009
- Title:
- Radial kinematics in bright cluster galaxies
- Short Name:
- J/MNRAS/391/1009
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the first of a series of papers devoted to the investigation of a large sample of brightest cluster galaxies (BCGs), their kinematic and stellar population properties, and the relationships between those and the properties of the cluster. We have obtained high signal-to-noise ratio, long-slit spectra of these galaxies with Gemini and William Herschel Telescope with the primary purpose of investigating their stellar population properties. This paper describes the selection methods and criteria used to compile a new sample of galaxies, concentrating on BCGs previously classified as containing a halo (cD galaxies), together with the observations and data reduction. Here, we present the full sample of galaxies, and the measurement and interpretation of the radial velocity and velocity dispersion profiles of 41 BCGs.
- ID:
- ivo://CDS.VizieR/J/ApJ/838/83
- Title:
- Radial velocities, abundances & membership in TriII
- Short Name:
- J/ApJ/838/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Among the Milky Way satellites discovered in the past three years, Triangulum II has presented the most difficulty in revealing its dynamical status. Kirby+ (2015ApJ...814L...7K) identified it as the most dark-matter-dominated galaxy known, with a mass-to-light ratio within the half-light radius of 3600_-2100_^+3500^M_{sun}_/L_{sun}_. On the other hand, Martin+ (2016ApJ...818...40M) measured an outer velocity dispersion that is 3.5+/-2.1 times larger than the central velocity dispersion, suggesting that the system might not be in equilibrium. From new multi-epoch Keck/DEIMOS measurements of 13 member stars in Triangulum II, we constrain the velocity dispersion to be {sigma}_v_<3.4km/s (90%C.L.). Our previous measurement of {sigma}_v_, based on six stars, was inflated by the presence of a binary star with variable radial velocity. We find no evidence that the velocity dispersion increases with radius. The stars display a wide range of metallicities, indicating that Triangulum II retained supernova ejecta and therefore possesses, or once possessed, a massive dark matter halo. However, the detection of a metallicity dispersion hinges on the membership of the two most metal-rich stars. The stellar mass is lower than galaxies of similar mean stellar metallicity, which might indicate that Triangulum II is either a star cluster or a tidally stripped dwarf galaxy. Detailed abundances of one star show heavily depressed neutron-capture abundances, similar to stars in most other ultra-faint dwarf galaxies but unlike stars in globular clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/399/353
- Title:
- Radial velocities in Hickson compact groups
- Short Name:
- J/ApJ/399/353
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial velocities have been observed for 457 galaxies in the 100 Hickson compact groups (Hickson =1982ApJ...255..382H; catalog <VII/85>). Brighter galaxies were observed over the period 1984-1986, using the 1.5m telescope of the F.L. Whipple Observatory on Mt. Hopkins, Arizona, in wavelength range 470-710nm; the remaining fainter galaxies were observed with the Canada-France-Hawaii Telescope (CFHT). These velocities are listed in table2. Dynamical parameters were derived for 92 of the 100 groups, which are listed in table3; Hubble constant was assumed to be Ho=100km/s/Mpc.
- ID:
- ivo://CDS.VizieR/J/A+A/482/53
- Title:
- Radial velocities of four LSB galaxies
- Short Name:
- J/A+A/482/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present integral-field spectroscopy of the ionized gas in the central regions of four galaxies with a low surface brightness disk taken with the Visible Multi Object Spectrograph at the Very Large Telescope and aimed at testing the accuracy in the determination of the central logarithmic slope alpha of the mass density radial profile rho(r){prop.to}r^alpha^ in this class of objects. For all the sample galaxies we subtracted the best-fit model of gas in circular motions from the observed velocity field and derived the residuals. Only ESO-LV5340200 is characterized by a regular velocity field. We extracted the velocity curves of this galaxy along several position angles, in order to estimate the uncertainty in deriving the central gradient of the total mass density from long-slit spectroscopy.
- ID:
- ivo://CDS.VizieR/J/A+A/448/155
- Title:
- Radial velocities of Leo I globular clusters
- Short Name:
- J/A+A/448/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- VLT/FLAMES radial velocities for 50 Globular Clusters (GCs), 37 field stars and 21 unclassified objects around the Leo I group galaxies NGC 3379 and NGC 3384 are presented. Object Id and BVR photometry are from Rhode & Zepf (2004AJ....127..302R). Positions (J2000.0) should be accurate to ~0"2 or better w.r.t. the GSC2.1 catalogue. Heliocentric radial velocities and their errors were estimated by fitting the peak (see the width, heigh, and Tonry & Davies (1979AJ.....84.1511T) coefficient) of the cross-correlation function (CCF) with the IRAF/RV package task FXCOR, using simulatenous and ELODIE library stellar templates. Objects have been assigned three quality class, class A being the most secure velocity determination, and class C the least secure; the latter objects require confirmation, and such GCs were not considered for the dynamical analysis presented in the paper.
- ID:
- ivo://CDS.VizieR/J/A+A/535/A39
- Title:
- Radial velocity survey toward NGC 6253
- Short Name:
- J/A+A/535/A39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- One of the most metal-rich open cluster of the Galaxy, NGC 6253 is a target of special interest in the search for extrasolar planets, the study of stellar populations, and the chemical/dynamical evolution of the Galactic disk. We present the results of two photometric campaigns and a VLT multi-epoch radial velocity survey toward the open cluster NGC 6253. We complement our analysis with photometric, proper motion, and radial velocity data available from previous studies of this cluster, and analyze three planetary candidates found in the field of NGC 6253.
- ID:
- ivo://CDS.VizieR/J/ApJ/534/114
- Title:
- RASSCALS: X-ray and optical study
- Short Name:
- J/ApJ/534/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the ROSAT All-Sky Survey Center for Astrophysics Loose Systems (RASSCALS), the largest X-ray and optical survey of low-mass galaxy groups to date. We draw 260 groups from the combined Center for Astrophysics and Southern Sky Redshift Surveys, covering one-quarter of the sky to a limiting Zwicky magnitude of m_z_=15.5.
- ID:
- ivo://CDS.VizieR/J/A+A/461/397
- Title:
- RASS-SDSS galaxy cluster survey. V.
- Short Name:
- J/A+A/461/397
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we consider a large sample of optically selected clusters, in order to elucidate the physical reasons for the existence of X-ray underluminous clusters. For this purpose we analyzed the correlations of the X-ray and optical properties of a sample of 137 spectroscopically confirmed Abell clusters in the SDSS database. We searched for the X-ray counterpart of each cluster in the ROSAT All Sky Survey. We find that 40% of our clusters have a marginal X-ray detection or remain undetected in X-rays. These clusters appear too X-ray faint on average for their mass as determined by velocity dispersion; i.e. they do not follow the scaling relation between X-ray luminosity and virial mass traced by the other clusters. On the other hand, they do follow the general scaling relation between optical luminosity and virial mass. We refer to these clusters as the X-ray-underluminous Abell clusters (AXU clusters, for short) and designate as "normal" the X-ray detected Abell systems. We separately examined the distributions and properties of the galaxy populations of the normal and the AXU clusters.
