- ID:
- ivo://CDS.VizieR/J/A+A/561/A94
- Title:
- Velocities and photometry in Trumpler 20
- Short Name:
- J/A+A/561/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Trumpler 20 is an old open cluster (OC) located toward the Galactic centre, at about 3kpc from the Sun and ~7kpc from the Galactic centre. Its position makes this cluster particularly interesting in the framework of the chemical properties of the Galactic disc because very few old OCs reside in the inner part of the disc. For this reason it has been selected as a cluster target of the Gaia-ESO Survey, and spectra of many stars in the main sequence and red clump phases are now available. Moreover, although it has been studied by several authors in the past, no consensus on the evolutionary status of Tr 20 has been reached. The heavy contamination of field stars (the line of sight of Tr 20 crosses the Carina spiral arm) complicates the correct interpretation. Another interesting aspect of the cluster is that it shows a broadened main sequence turn-off and a prominent and extended red clump, characteristics that are not easily explained by classical evolutionary models. Exploiting both spectroscopic information from the Gaia-ESO Survey (and the ESO archive) and literature photometry, we obtain a detailed and accurate analysis of the properties of the cluster. We make use of the first accurate metallicity measurement ever obtained from several spectra of red clump stars, and of cluster membership determination using radial velocities. According to the evolutionary models adopted, we find that Tr 20 has an age in the range 1.35-1.66Gyr, an average reddening E(B-V) in the range 0.31-0.35mag, a distance modulus (m-M)_0_ between 12.64 and 12.72mag. The spectroscopic metallicity is [Fe/H]=+0.17dex. We discuss the structural properties of the object and constrain possible hypotheses for its broadened upper main sequence, by estimating the effect of differential reddening, and its extended red clump.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AN/336/70
- Title:
- Velocities and proper motions of Galactic Cepheids
- Short Name:
- J/AN/336/70
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The kinematics and distribution of classical Cepheids within ~3 kpc from the Sun suggest the existence of the outer ring R1R2' in the Galaxy. The optimum value of the solar position angle with respect to the major axis of the bar, theta_b, providing the best agreement between the distribution of Cepheids and model particles is theta_b_=37+/-13{deg}. The kinematical features obtained for Cepheids with negative Galactocentric radial velocity V_R_ are consistent with the solar location near the descending segment of the outer ring R2. The sharp rise of extinction toward of the Galactic center can be explained by the presence of the outer ring R1 near the Sun.
- ID:
- ivo://CDS.VizieR/J/ApJ/649/201
- Title:
- Velocities and Washington photometry in Carina dSph
- Short Name:
- J/ApJ/649/201
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new large-area Washington M, T2+DDO51 filter survey of more than 10deg^2^ around the Carina dSph galaxy reveals a spectroscopically confirmed power-law radial density break population of Carina giant stars extending several degrees beyond the central King profile. Magellan telescope MIKE spectroscopy establishes the existence of Carina stars to at least 4.5 times its central King limiting radius, rlim, and primarily along Carina's major axis. To keep these stars bound to the dSph would require a global Carina mass-to-light ratio of M/L>=6300(M/L)_{sun}}. The MIKE velocities, supplemented with ~950 additional Carina field velocities from archived VLT+GIRAFFE spectra with r<~rlim, demonstrate a nearly constant Carina velocity dispersion (sigma_v_) to just beyond r=rlim and both a rising and a velocity shear at still larger radii. Together, the observational evidence suggests that the discovered extended Carina population represents tidal debris from the dSph.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/739
- Title:
- Velocities for seven transiting hot Jupiters
- Short Name:
- J/MNRAS/426/739
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present seven new transiting hot Jupiters from the WASP-South survey. The planets are all typical hot Jupiters orbiting stars from F4 to K0 with magnitudes of V=10.3-12.5. The orbital periods are all in the range of 3.9-4.6d, the planetary masses range from 0.4 to 2.3-M_Jup_ and the radii from 1.1 to 1.4R_Jup_. In line with known hot Jupiters, the planetary densities range from Jupiter-like to inflated ({rho}=0.13-1.07{rho}_Jup_). We use the increasing numbers of known hot Jupiters to investigate the distribution of their orbital periods and the 3-4d 'pile-up'.
- ID:
- ivo://CDS.VizieR/J/ApJ/562/254
- Title:
- Velocities in A1750, A3395 and A3528
- Short Name:
- J/ApJ/562/254
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study three prominent bimodal X-ray clusters: A3528, A1750, and A3395. Using observations taken with ROSAT and ASCA, we analyze the temperature and surface brightness distributions. We also analyze the velocity distributions of the three clusters using new measurements supplemented with previously published data. We examine both the overall cluster properties, as well as the two subcluster elements in each. These results are then applied to the determination of the overall cluster masses; they demonstrate excellent consistency between the various methods used. While the characteristic parameters of the subclusters are typical of isolated objects, our temperature results for the regions between the two subclusters clearly confirm the presence of merger activity. These three clusters represent a progression of equal-sized subcluster mergers, starting from initial contact to immediately before first core passage.
16756. Velocities in Abell 3266
- ID:
- ivo://CDS.VizieR/J/AJ/112/36
- Title:
- Velocities in Abell 3266
- Short Name:
- J/AJ/112/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 387 velocities covering an area 1.8x1.8{deg}^2^, including 229 new galaxy velocities obtained from 309 spectra, of which 317 appear to be cluster members according to our analysis. Based on this extended velocity sample we reanalyzed the velocity structure of the cluster. We found a strongly decreasing velocity dispersion profile that, as well as the mean velocity, shows significant radial scatter. Inside the 2.5h_50_^-1^Mpc radius, the velocity dispersion has a value of 1306+/-73km/s, while further out than 3h_50_^-1^Mpc it falls below 800km/s. The global dispersion is 1085+/-51km/s. We found a remarkable velocity substructure, which we interpret as a tidal outgoing arm reaching from the center to the northernmost extensions surveyed. The arm could be produced by a recent merger with another cluster, that moved from the front and SW direction and scattered from the main cluster core into the arm. This model allows us to derive an epoch for the collision between the more massive core and the front edge of the incoming cluster of 4x10^9^h_50_^-1^yr ago and of ~2x10^9^h_50_^-1^yr for the merging of both cores. Formation of the dumb-bell is a later merger process of the two BCMs, consistent with theoretical estimates. The collision picture is also consistent with the distorted X-ray image. The very northernmost parts of the arm could, alternatively, be interpreted as ongoing infall of a few outlying loose groups. The suggestion of a faint galaxy system within 400h_50_^-1^kpc, satellite to the central dumb-bell, is maintained in spite of the large central velocity dispersion value; however, confirmation requires data for further compact faint members. From several mass estimators we derived a cluster dynamical mass value of 5x10^15^h_50_^-1^M_{sun}_, but this value should be seen in the merger context described.
- ID:
- ivo://CDS.VizieR/J/ApJ/665/1067
- Title:
- Velocities in Cl 0024+16 and MS 0451-03
- Short Name:
- J/ApJ/665/1067
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine resolved spectroscopic data obtained with the Keck II telescope for 44 spheroidal galaxies in the fields of two rich clusters, Cl 0024+16 (z=0.40) and MS 0451-03 (z=0.54) and contrast this with similar data for 23 galaxies within the redshift interval 0.3<z<0.65 in the GOODS northern field. For each galaxy we examine the case for systemic rotation, derive central stellar velocity dispersions sigma and photometric ellipticities epsilon. Using morphological classifications obtained via Hubble Space Telescope imaging as the basis, we explore the utility of our kinematic quantities in distinguishing between pressure-supported ellipticals and rotationally supported lenticulars (S0s).
- ID:
- ivo://CDS.VizieR/J/AJ/105/1251
- Title:
- Velocities in Pisces-Perseus supercluster.
- Short Name:
- J/AJ/105/1251
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Measurements of 544 radial velocities, 229 optical and 315 in the 21cm HI line, are presented for galaxies, mostly in the declination strip +33.5 deg<Dec<+39.5deg in the region of the Pisces-Perseus supercluster. These are combined with other available data to investigate the linear structure identified as the main supercluster ridge. The main ridge of the supercluster extends at least 50h^-1Mpc before it disappears into the zone of avoidance east of Perseus. Confinement both on the plane of the sky and in the velocity dimension imply an axial ratio of greater than ten to one and an inclination with respect to the plane of the sky of less than about 12 degrees. The smoothed volume density contrast over the whole ridge averages more than a factor of 6 relative to the average density derived for the whole sample. The relative proximity, low inclination to the plane of the sky, and high contrast relative to the foreground and background, help to make the Pisces-Perseus filament one of the most prominent features in the extragalactic sky on large scales.
- ID:
- ivo://CDS.VizieR/J/A+A/462/683
- Title:
- Velocities in SMC field of NGC 330
- Short Name:
- J/A+A/462/683
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We search for the effects of metallicity on B and Be stars in the Small and Large Magellanic Clouds (SMC and LMC) and in the Milky Way (MW), by extending our previous analysis of B and Be star populations in the LMC to the SMC. The rotational velocities of massive stars and the evolutionary status of Be stars are examined with respect to their environments. Spectroscopic observations of hot stars belonging to the young cluster SMC-NGC 330 and its surrounding region were obtained with the VLT-GIRAFFE facilities in MEDUSA mode. We determined fundamental parameters for B and Be stars with the GIRFIT code, taking the effect of fast rotation and the age of observed clusters into account. We compared the mean vsini obtained by spectral type- and mass-selection for field and cluster B and Be stars in the SMC with the one in the LMC and MW.
- ID:
- ivo://CDS.VizieR/J/A+A/521/A78
- Title:
- Velocities in the A2345 cluster
- Short Name:
- J/A+A/521/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The connection of cluster mergers with the presence of extended, diffuse radio sources in galaxy clusters is still debated. We aim to obtain new insights into the internal dynamics of the cluster Abell 2345. This cluster exhibits two non-symmetric radio relics well studied through recent, deep radio data. Our analysis is based on redshift data for 125 galaxies acquired at the Telescopio Nazionale Galileo and on new photometric data acquired at the Isaac Newton Telescope. We also use ROSAT/HRI archival X-ray data. We combine galaxy velocities and positions to select 98 cluster galaxies and analyze the internal dynamics of the cluster.