- ID:
- ivo://CDS.VizieR/J/MNRAS/470/3937
- Title:
- 1876 open clusters multimembership catalog
- Short Name:
- J/MNRAS/470/3937
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The main objective of this work is to determine the cluster members of 1876 open clusters, using positions and proper motions of the astrometric fourth United States Naval Observatory (USNO) CCD Astrograph Catalog (UCAC4). For this purpose, we apply three different methods, all based on a Bayesian approach, but with different formulations: a purely parametric method, another completely non-parametric algorithm and a third, recently developed by Sampedro & Alfaro (2016MNRAS.457.3949S), using both formulations at different steps of the whole process. The first and second statistical moments of the members' phase-space subspace, obtained after applying the three methods, are compared for every cluster. Although, on average, the three methods yield similar results, there are also specific differences between them, as well as for some particular clusters. The comparison with other published catalogues shows good agreement. We have also estimated, for the first time, the mean proper motion for a sample of 18 clusters. The results are organized in a single catalogue formed by two main files, one with the most relevant information for each cluster, partially including that in UCAC4, and the other showing the individual membership probabilities for each star in the cluster area. The final catalogue, with an interface design that enables an easy interaction with the user, is available in electronic format at the Stellar Systems Group (SSG-IAA) web site (http://ssg.iaa.es/en/content/sampedro-cluster-catalog).
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/640/A9
- Title:
- Open star cluster Coma Berenices multi-photometry
- Short Name:
- J/A+A/640/A9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We mainly aim to search for the lithium depletion boundary (LDB) among the sub-stellar population of the open star cluster Coma Berenices. Since the number of brown dwarf candidates in Coma Ber available in the literature is scarce, we carried out a search for additional candidates photometrically using colour-magnitude diagrams combining optical and infrared photometry from the latest public releases of the following large-scale surveys: the United Kingdom InfraRed Telescope Infrared Deep Sky Survey (UKIRT/UKIDSS), the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS), the Sloan Digital Sky Survey (SDSS), and AllWISE. We checked astrometric consistency with cluster membership using Gaia DR2. A search for Li in three new and five previously known brown dwarf candidate cluster members was performed via spectroscopic observations using the OSIRIS instrument at the 10.4m Gran Telescopio de Canarias (GTC). A couple dozen new photometric candidate brown dwarfs located inside the tidal radius of Coma Ber are reported, but none of these are significantly fainter and cooler than previously known members. No LiI resonance doublet at 6707.8{AA} was detected in any of eight Coma Ber targets in the magnitude range J=15-19 and G=20-23 observed with the GTC. Spectral types and radial velocities were derived from the GTC spectra. These values confirm the cluster membership of four L2-L2.5 dwarfs, two of which are new in the literature. The large Li depletion factors found among the four bona fide sub-stellar members in Coma Ber implies that the LDB must be located at spectral type later than L2.5 in this cluster. Using the latest evolutionary models for brown dwarfs, a lower limit of 550Myr on the cluster age is set. This constraint has been combined with other dating methods to obtain an updated age estimate of 780+/-230Myr for the Coma Ber open cluster. Identification of significantly cooler sub-stellar cluster members in Coma Ber awaits the advent of the Euclid wide survey, which should reach a depth of about J=23; this superb sensitivity will make it possible to determine the precise location of the sub-stellar LDB in this cluster and to carry out a complete census of its sub-stellar population.
- ID:
- ivo://CDS.VizieR/J/AJ/144/16
- Title:
- Optical and HI properties of galaxies in voids
- Short Name:
- J/AJ/144/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carefully selected a sample of 60 galaxies that reside in the deepest underdensities of geometrically identified voids within the Sloan Digital Sky Survey. HI imaging of 55 galaxies with the Westerbork Synthesis Radio Telescope reveals morphological and kinematic signatures of ongoing interactions and gas accretion. We probe a total volume of 485Mpc^3^ within the voids, with an angular resolution of 8kpc at an average distance of 85Mpc. We reach column density sensitivities of 5x10^19^/cm^-2^, corresponding to an HI mass limit of 3x10^8^M_{sun}_. We detect HI in 41 galaxies, with total masses ranging from 1.7x10^8^ to 5.5x10^9^M_{sun}_. The upper limits on the 14 non-detections are not inconsistent with their luminosities, given their expected HI mass-to-light ratios. We find that the void galaxies are generally gas-rich, low-luminosity, blue disk galaxies, with optical and HI properties that are not unusual for their luminosity and morphology. The sample spans a range of absolute magnitudes (-16.1>M_r_>-20.4) and colors (0.06<g-r<0.87), and includes disk and irregular galaxies. We also identify three as early-type galaxies, all of which are not detected in HI. All galaxies have stellar masses less than 3x10^10^M_{sun}_, and many have kinematic and morphological signs of ongoing gas accretion, suggesting that the void galaxy population is still in the process of assembling. The small-scale clustering in the void, within 600kpc and 200km/s, is similar to that in higher density regions, and we identify 18 HI-rich neighboring galaxies in the voids. Most are within 100kpc and 100km/s of the targeted galaxy, and we find no significant population of HI-rich low-luminosity galaxies filling the voids, contrary to what is predicted by simulations.
- ID:
- ivo://CDS.VizieR/J/A+A/564/A29
- Title:
- Optical and near-infrared photometry in Orion A
- Short Name:
- J/A+A/564/A29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Following the recent discovery a large population of young stars in front of the Orion Nebula we carried out an observational campaign with the DECam wide-field camera covering approximately 10 square degrees centered on NGC 1980 to confirm, probe the extent, and characterize this foreground population of pre-main sequence stars. We used multi-wavelength wide field images and catalogs to identify potential foreground pre-main sequence stars using a novel probabilistic technique based on a careful selection of colors and luminosities. We confirmed the presence of a large foreground population towards the Orion A cloud. This population contains several distinct sub-groups including NGC 1980 and NGC 1981 and stretches over several degrees in front of the Orion A cloud. By comparing the location of their sequence in various color-magnitude diagrams to other clusters, we found a distance and an age of 380pc and 5 to 10Myr, in good agreement with previous estimates. Our final sample includes 2123 candidate members and is complete from below the hydrogen burning limit to about 0.3M_{sun}_ where the data starts to be limited by saturation. Extrapolating the mass function to the high masses, we estimated a total number of ~2600 members in the surveyed region.
- ID:
- ivo://CDS.VizieR/J/AJ/131/2426
- Title:
- Optical and radio study of Abell 2111
- Short Name:
- J/AJ/131/2426
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an in-depth analysis of the Butcher-Oemler cluster A2111, including new optical spectroscopy plus a deep Very Large Array (VLA) radio continuum observation. These are combined with optical imaging from the Sloan Digital Sky Survey (SDSS) to assess the activity and properties of member galaxies. Prior X-ray studies have suggested A2111 to be a head-on cluster merger, a dynamical state that might be connected to the high level of activity inferred from its blue fraction. We are able to directly assess this claim, using our spectroscopic data to identify 95 cluster members among 196 total galaxy spectra. We are able to detect 175 optical sources from the SDSS in our VLA radio data, of which 35 have redshift information.
- ID:
- ivo://CDS.VizieR/J/MNRAS/421/2982
- Title:
- Optical and UV colors of Coma galaxies
- Short Name:
- J/MNRAS/421/2982
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present and analyse optical and ultraviolet (UV) colours for passive and optically-red Coma cluster galaxies for which we have spectroscopic age and element abundance estimates. Our sample of 150 objects covers a wide range in mass, from giant ellipticals down to the bright end of the dwarf-galaxy regime. Galaxies with ongoing star formation have been removed using strict H{alpha} emission-line criteria. We focus on the colours FUV-i, NUV-i, FUV-NUV, u*-g and g-i. We find that all of these colours are correlated with both luminosity and velocity dispersion at the >5{sigma} level, with FUV-i and FUV-NUV becoming bluer with increasing 'mass' while the other colours become redder. We perform a purely empirical analysis to assess what fraction of the variation in each colour can be accounted for by variations in the average stellar populations, as traced by the optical spectra.
- ID:
- ivo://CDS.VizieR/J/MNRAS/401/294
- Title:
- Optical identification of XMM-LSS sources
- Short Name:
- J/MNRAS/401/294
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical spectroscopic identifications of X-ray sources in ~3deg^2^ of the XMM-Large Scale Structure survey (XMM-LSS), also covered by the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS), obtained with the AAOmega instrument at the Anglo-Australian Telescope. In a flux-limited sample of 829 point-like sources in the optical band with g'<=22mag and the 0.5-2keV flux (f_0.5-2keV_)>10^-15^erg/cm^2^/s, we observed 693 objects and obtained reliable spectroscopic identification for 487 sources, approximately 59 per cent of the overall sample.
- ID:
- ivo://CDS.VizieR/J/AJ/139/390
- Title:
- Optically selected BL Lac objects from SDSS-DR7
- Short Name:
- J/AJ/139/390
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 723 optically selected BL Lac candidates from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) spectroscopic database encompassing 8250deg^2^ of sky; our sample constitutes one of the largest uniform BL Lac samples yet derived. Each BL Lac candidate has a high-quality SDSS spectrum from which we determine spectroscopic redshifts for ~60% of the objects. Redshift lower limits are estimated for the remaining objects utilizing the lack of host galaxy flux contamination in their optical spectra; we find that objects lacking spectroscopic redshifts are likely at systematically higher redshifts.
- ID:
- ivo://CDS.VizieR/J/ApJ/651/61
- Title:
- Optically thick absorbers near luminous quasars
- Short Name:
- J/ApJ/651/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With close pairs of quasars at different redshifts, a background quasar sight line can be used to study a foreground quasar's environment in absorption. We search 149 moderate-resolution background quasar spectra from Gemini, Keck, the MMT, and the SDSS to survey Lyman limit systems (LLSs) and damped Ly{alpha} systems (DLAs) in the vicinity of 1.8<z<4.0 luminous foreground quasars. A sample of 27 new quasar-absorber pairs is uncovered with column densities 10^17.2^cm^-2^<NH<10^20.9^cm^-2^ and transverse (proper) distances of 22h^-1^kpc<R<1.7h^-1^Mpc from the foreground quasars.
- ID:
- ivo://CDS.VizieR/J/A+A/566/A60
- Title:
- Optical-NIR catalog of AKARI NEP Deep Field
- Short Name:
- J/A+A/566/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an 8-band (u*, g', r', i', z', Y, J, Ks) optical to near-infrared deep photometric catalogue based on the observations made with MegaCam and WIRCam at CFHT, and compute photometric redshifts, zph in the North Ecliptic Pole (NEP) region, where AKARI infrared satellite carried out deep survey at near to mid infrared wavelength. We designed the catalogue to include sources detected in z' band with counterparts in at least one of the other bands, and found 85797 sources in the NEP field. Comparing with galaxy spectroscopic redshifts, photometric redshift dispersion {sigma}({Delta}z/(1+z)) is 0.032 and catastrophic failure rate {Delta}z/(1+z)>0.15 is 5.8% at z<1. Our redshifts are highly accurate with z'<22 at zph<2.5 and for fainter sources with z'<24 at z<1.
