- 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/AJ/157/144
- Title:
- Protoplanetary disk masses in Taurus
- Short Name:
- J/AJ/157/144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Measuring the masses of protoplanetary disks is crucial for understanding their planet-forming potential. Typically, dust masses are derived from (sub-)millimeter flux density measurements plus assumptions for the opacity, temperature, and optical depth of the dust. Here we use radiative transfer models to quantify the validity of these assumptions with the aim of improving the accuracy of disk dust mass measurements. We first carry out a controlled exploration of disk parameter space. We find that the disk temperature is a strong function of disk size, while the optical depth depends on both disk size and dust mass. The millimeter-wavelength spectral index can be significantly shallower than the naive expectation due to a combination of optical depth and deviations from the Rayleigh-Jeans regime. We fit radiative transfer models to the spectral energy distributions (SEDs) of 132 disks in the Taurus-Auriga region using a Markov chain Monte Carlo approach. We used all available data to produce the most complete SEDs used in any extant modeling study. We perform the fitting twice: first with unconstrained disk sizes and again imposing the disk size-brightness relation inferred for sources in Taurus. This constraint generally forces the disks to be smaller, warmer, and more optically thick. From both sets of fits, we find disks to be ~1-5 times more massive than when derived using (sub-)millimeter measurements and common assumptions. With the uncertainties derived from our model fitting, the previously measured dust mass-stellar mass correlation is present in our study but only significant at the 2{sigma} level.
523. (16) Psyche images
- ID:
- ivo://CDS.VizieR/J/A+A/619/L3
- Title:
- (16) Psyche images
- Short Name:
- J/A+A/619/L3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Asteroid (16) Psyche is the target of the NASA Psyche mission. It is considered one of the few main-belt bodies that could be an exposed proto-planetary metallic core and that would thus be related to iron meteorites. Such an association is however challenged by both its near- and mid-infrared spectral properties and the reported estimates of its density. Here, we aim to refine the density of (16) Psyche to set further constraints on its bulk composition and determine its potential meteoritic analog. We observed (16) Psyche with ESO VLT/SPHERE/ZIMPOL as part of our large program (ID 199.C-0074). We used the high angular resolution of these observations to refine Psyche's three-dimensional (3D) shape model and subsequently its density when combined with the most recent mass estimates. In addition, we searched for potential companions around the asteroid. We derived a bulk density of 3.99+/-0.26g/cm^3^ for Psyche. While such density is incompatible at the 3-sigma level with any iron meteorites (~7.8g/cm^3^), it appears fully consistent with that of stony-iron meteorites such as mesosiderites (density ~4.25g/cm^3^). In addition, we found no satellite in our images and set an upper limit on the diameter of any non-detected satellite of 1460+/-200m at 150km from Psyche (0.2%xR_Hill_, the Hill radius) and 800+/-200m at 2000km (3%xRHill). Considering that the visible and near-infrared spectral properties of mesosiderites are similar to those of Psyche, there is merit to a long-published initial hypothesis that Psyche could be a plausible candidate parent body for mesosiderites.
- ID:
- ivo://CDS.VizieR/J/A+A/638/L15
- Title:
- (16) Psyche. VLT/SPHERE images and shape models
- Short Name:
- J/A+A/638/L15
- Date:
- 23 Mar 2022
- Publisher:
- CDS
- Description:
- Asteroid (16) Psyche is the largest M-type asteroid in the main belt and the target of the NASA Psyche mission. It is also the only asteroid of this size (D>200km) known to be metal rich. Although various hypotheses have been proposed to explain the rather unique physical properties of this asteroid, a perfect understanding of its formation and bulk composition is still missing. We aim to refine the shape and bulk density of (16) Psyche and to perform a thorough analysis of its shape to better constrain possible formation scenarios and the structure of its interior. We obtained disk-resolved VLT/SPHERE/ZIMPOL images acquired within our ESO large program (ID 199.C-0074), which complement similar data obtained in 2018. Both data sets offer a complete coverage of Psyche's surface. These images were used to reconstruct the three-dimensional (3D) shape of Psyche with two independent shape modeling algorithms (MPCD and ADAM). A shape analysis was subsequently performed, including a comparison with equilibrium figures and the identification of mass deficit regions. Our 3D shape along with existing mass estimates imply a density of 4.20+/-0.60g/cm^3, which is so far the highest for a solar system object following the four telluric planets. Furthermore, the shape of Psyche presents small deviations from an ellipsoid, that is, prominently three large depressions along its equator. The flatness and density of Psyche are compatible with a formation at hydrostatic equilibrium as a Jacobi ellipsoid with a shorter rotation period of ~3h. Later impacts may have slowed down Psyche's rotation, which is currently ~4.2h, while also creating the imaged depressions. Our results open the possibility that Psyche acquired its primordial shape either after a giant impact while its interior was already frozen or while its interior was still molten owing to the decay of the short-lived radionuclide ^26^Al.
- ID:
- ivo://CDS.VizieR/J/A+A/478/321
- Title:
- QSO Type1/Type2 dichotomy
- Short Name:
- J/A+A/478/321
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For Seyfert galaxies, the AGN unification model provides a simple and well-established explanation of the type 1/type 2 dichotomy through orientation-based effects. The generalization of this unification model to the higher luminosity AGNs that quasars are remains a key question. The recent detection of type 2 radio-quiet quasars seems to support such an extension. We propose a further test of this scenario. On the basis of a compilation of quasar host-galaxy position angles consisting of previously published data and of new measurements performed using HST Archive images, we investigate the possible existence of a correlation between the linear polarization position angle and the host-galaxy/extended emission position angle of quasars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/2437
- Title:
- Quantified H I morphology of WHISP sample
- Short Name:
- J/MNRAS/416/2437
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The morphology of the atomic hydrogen (HI) disc of a spiral galaxy is the first component to be disturbed by a gravitational interaction such as a merger between two galaxies. We use a simple parametrization of the morphology of HI column density maps of the Westerbork observations of neutral Hydrogen in Irregular and SPiral galaxies (WHISP) project to select those galaxies that are likely undergoing a significant interaction. Merging galaxies occupy a particular part of parameter space defined by Asymmetry (A), the relative contribution of the 20 per cent brightest pixels to the second-order moment of the column density map (M20) and the distribution of the second-order moment over all the pixels (GM). Based on their HI morphology, we find that 13 per cent of the WHISP galaxies are in an interaction (Concentration-M20) and only 7 per cent are based on close companions in the data cube. This apparent discrepancy can be attributed to the difference in visibility time-scales: mergers are identifiable as close pairs for 0.5 Gyr but are identifiable for ~1Gyr by their disturbed HI morphology. Expressed as volume merger rates, the two estimates agree very well: 7 and 6.8x10^-3^mergers/Gyr/Mpc^3^ for paired and morphologically disturbed HI discs, respectively.
- ID:
- ivo://CDS.VizieR/J/MNRAS/427/3159
- Title:
- Quantified HI morphology. VI. NUV/FUV
- Short Name:
- J/MNRAS/427/3159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extended ultraviolet (XUV) discs have been found in a substantial fraction of late-type - S0, spiral and irregular - galaxies. Similarly, most late-type spirals have an extended gas disc, observable in the 21-cm radio line (HI). The morphology of galaxies can be quantified well using a series of scale-invariant parameters; concentration-asymmetry-smoothness (CAS), Gini, M_20_, and G_M_ parameters. In this series of papers, we apply these to HI column density maps to identify mergers and interactions, lopsidedness and now XUV discs. In this paper, we compare the quantified morphology and effective radius (R_50_) of the Westerbork observations of neutral Hydrogen in Irregular and SPiral galaxies Project (WHISP) HI maps to those of far- and near-ultraviolet images obtained with GALEX, to explore how close the morphology and scales of HI and UV in these discs correlate. We find that XUV discs do not stand out by their effective radii in UV or HI. However, the concentration index in far-ultraviolet (FUV) appears to select some XUV discs. And known XUV discs can be identified via a criterion using asymmetry and M_20_; 80 per cent of XUV discs are included but with 55 per cent contamination. This translates into 61 candidate XUV disc out of our 266 galaxies, 23 per cent consistent with previous findings. Otherwise, the UV and HI morphology parameters do not appear closely related.
- ID:
- ivo://CDS.VizieR/J/ApJ/703/1569
- Title:
- Radial distribution in SINGS galaxies. I.
- Short Name:
- J/ApJ/703/1569
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ultraviolet through far-infrared (FIR) surface brightness profiles for the 75 galaxies in the Spitzer Infrared Nearby Galaxies Survey (SINGS). The imagery used to measure the profiles includes Galaxy Evolution Explorer UV data, optical images from Kitt Peak National Observatory, Cerro Tololo Inter-American Observatory, and Sloan Digital Sky Survey, near-IR data from Two Micron All Sky Survey, and mid- and FIR images from Spitzer. Along with the radial profiles, we also provide multi-wavelength asymptotic magnitudes and several nonparametric indicators of galaxy morphology: the concentration index (C42), the asymmetry (A), the Gini coefficient (G), and the normalized second-order moment of the brightest 20% of the galaxy's flux ({overline}M_20_). In this paper, the first of a series, we describe the technical aspects regarding the surface photometry, and present a basic analysis of the global and structural properties of the SINGS galaxies at different wavelengths.
- ID:
- ivo://CDS.VizieR/J/A+A/515/A57
- Title:
- Radial velocities in clusters of galaxies. V.
- Short Name:
- J/A+A/515/A57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a part of our galaxy-cluster redshift survey, we present a set of 79 new velocities in the 4 clusters Abell 376, Abell 970, Abell 1356, and Abell 2244, obtained at Haute-Provence observatory. This set now completes our previous analyses, especially for the first two clusters. Data on individual galaxies are presented, and we discuss some cluster properties.
- ID:
- ivo://CDS.VizieR/J/AJ/141/182
- Title:
- Radio and optical properties of QSOs
- Short Name:
- J/AJ/141/182
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the largest homogeneous quasar sample with high-quality optical spectra and robust radio morphology classifications assembled to date, we investigate relationships between radio and optical properties with unprecedented statistical power. The sample consists of 4714 radio quasars from FIRST with S_20_>=2mJy and with spectra from the Sloan Digital Sky Survey (SDSS). Radio morphology classes include core-only (core), core-lobe (lobe), core-jet (jet), lobe-core-lobe (triple), and double-lobe.
