- ID:
- ivo://CDS.VizieR/J/AJ/132/1669
- Title:
- Wide-field CCD phot. around nine open clusters
- Short Name:
- J/AJ/132/1669
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we study the evolution of the core and corona of nine open clusters using the projected radial density profiles derived from homogeneous CCD photometric data obtained with the 105cm Kiso Schmidt telescope. The age and galactocentric distance of the target clusters vary from 16 to 2000Myr and 9 to 10.8kpc, respectively. Barring Be 62, which is a young open cluster, other clusters show a uniform reddening across the cluster region.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/563/A80
- Title:
- Wide field imagers ground-based astrometry. V.
- Short Name:
- J/A+A/563/A80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-precision astrometry requires accurate point-spread function modeling and accurate geometric-distortion corrections. This paper demonstrates that it is possible to achieve both requirements with data collected at the High Acuity Wide-field K-band Imager (HAWK-I); a wide-field imager installed at the Nasmyth focus of UT4/VLT ESO 8m telescope. Our final astrometric precision reaches ~3mas per coordinate for a well exposed star in a single image, with a systematic error less than 0.1mas. We constructed calibrated astro-photometric catalogs and atlases of 7 fields: the Baade's window, NGC 6656, NGC 6121, NGC 6822, NGC 6388, NGC 104, and the James Webb Space Telescope calibration field (in the LMC). We make these catalogs and images electronically available to the community. Furthermore, as a demonstration of the efficacy of our approach, combining archival material taken with the optical wide-field imager at the MPI/ESO 2.2m with HAWK-I observations, we are able to achieve an excellent separation between cluster members and field objects for NGC 6656 and NGC 6121 with a time base-line of about 8 years. Using both HST and HAWK-I data, we also study the radial distribution of the SGB populations in NGC 6656 and conclude that the radial trend is flat, within our uncertains. We also provide membership probabilities for most of the stars in NGC 6656 and NGC 6121 catalogs and estimate membership for the published variable stars in these two fields.
- ID:
- ivo://CDS.VizieR/J/ApJS/220/17
- Title:
- Wide-field NIR polarimetry of {rho} Oph cloud
- Short Name:
- J/ApJS/220/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We conducted wide and deep simultaneous JHK_s_-band imaging polarimetry of the {rho} Ophiuchi cloud complex. Aperture polarimetry in the JHK_s_ band was conducted for 2136 sources in all three bands, of which 322 sources have significant polarizations in all the JHK_s_ bands and have been used for a discussion of the core magnetic fields. There is a positive correlation between degrees of polarization and H-K_s_ color up to H-K_s_~3.5. The magnetic field structures in the core region are revealed up to at least A_V_~47mag and are unambiguously defined in each sub-region (core) of Oph-A, Oph-B, Oph-C, Oph-E, Oph-F, and Oph-AC. Their directions, degrees of polarization, and polarization efficiencies differ but their changes are gradual; thus, the magnetic fields appear to be connected from core to core, rather than as a simple overlap of the different cloud core components. Comparing our results with the large-scale field structures obtained from previous optical polarimetric studies, we suggest that the magnetic field structures in the core were distorted by the cluster formation in this region, which may have been induced by shock compression due to wind/radiation from the Scorpius-Centaurus association.
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/927
- Title:
- Wide-field optical imaging of 4 fields
- Short Name:
- J/MNRAS/416/927
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present u-, g-, r-, i- and z-band optical images and associated catalogues taken primarily with the Isaac Newton Telescope Wide Field Camera on the European Large Area ISO Survey (ELAIS) N1 and N2, First Look Survey and Lockman Hole fields comprising a total of 1000h of integration time over 80deg^2^ and approximately 4.3 million objects. In this paper we outline the observations and data processing and characterize the completeness, reliability, photometric and astrometric accuracy of this data set. All images have been photometrically calibrated using the Sloan Digital Sky Survey and a uniform and homogeneous data set is composed over all the observed fields. Magnitude limits are u, g, r, i, z of 23.9, 24.5, 24.0, 23.3, 22.0 (AB, 5{sigma}). These data have been used for optical identification of past and ongoing projects including the surveys ELAIS, Spitzer Wide-Area Infrared Extragalactic Survey, Spitzer Extragalactic Representative Volume Survey and Herschel Multi-tiered Extragalactic Survey.
- ID:
- ivo://CDS.VizieR/J/ApJ/819/1
- Title:
- Wide-field photometry of the GC Palomar 5
- Short Name:
- J/ApJ/819/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of wide-field photometric surveys of the Palomar 5 globular cluster and its stellar stream, based on g- and r-band measures together with narrow-band DDO 51 photometry. In this first study, we use the deep (g, r) data to measure the incidence of gaps and peaks along the stream. Examining the star-counts profile of the stream plus contaminating populations, we find no evidence for significant underdensities, and find only a single significant overdensity. This is at odds with earlier studies based on matched-filter maps derived from shallower SDSS data if the contaminating population possesses plausible spatial properties. The lack of substantial substructure along the stream may be used in future dynamical simulations to examine the incidence of dark matter sub-halos in the Galactic halo. We also present a measurement of the relative distances along the stream, which we use to create the deepest wide-field map of this system to date. Universe}
21406. Wide-Field Plate Database
- ID:
- ivo://CDS.VizieR/VI/90
- Title:
- Wide-Field Plate Database
- Short Name:
- VI/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Wide-Field Plate Database (WFPDB) contains the descriptive information for the astronomical wide-field (~>1deg.) photographic observations stored in numerous archives all over the world. When finished it will provide an on-line access to the information for about 2 million observations from nearly 300 archives, obtained since the end of last century. Presently the WFPDB includes data for about 330 000 observations from 57 plate catalogues. About 120 000 observations more from 32 plate catalogs are in preparation to be included in the database. The WFPDB provides for each observation information for the corresponding archive, the parameters of the observational instrument, the observation parameters (position on sky, observation time, object name, method, exposure time, emulsion type, filter type, spectral band, plate size), as well as data on the plate quality, comments, and observers. Data on the plate availability and digitization will be supplemented in the WFPDB in the future.
- ID:
- ivo://CDS.VizieR/J/ApJ/835/212
- Title:
- Wide-field spectrosc. survey of GCs in Virgo cluster
- Short Name:
- J/ApJ/835/212
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a wide-field spectroscopic survey of globular clusters (GCs) in the Virgo cluster. We obtain spectra for 201 GCs and 55 ultracompact dwarfs (UCDs) using Hectospec on the Multiple-Mirror Telescope and derive their radial velocities. We identify 46 genuine intracluster GCs (IGCs), not associated with any Virgo galaxies, using the 3D GMM test on the spatial and radial velocity distribution. They are located at a projected distance 200kpc<~R<~500kpc from the center of M87. The radial velocity distribution of these IGCs shows two peaks, one at v_r_=1023km/s, associated with the Virgo main body, and another at v_r_=36km/s, associated with the infalling structure. The velocity dispersion of the IGCs in the Virgo main body is {sigma}_GC_~314km/s, which is smoothly connected to the velocity dispersion profile of M87 GCs but is much lower than that of dwarf galaxies in the same survey field, {sigma}_dwarf_~608km/s. The UCDs are more centrally concentrated on massive galaxies-M87, M86, and M84. The radial velocity dispersion of the UCD system is much smaller than that of dwarf galaxies. Our results confirm the large-scale distribution of Virgo IGCs indicated by previous photometric surveys. The color distribution of the confirmed IGCs shows a bimodality similar to that of M87 GCs. This indicates that most IGCs are stripped off dwarf galaxies and some off massive galaxies in the Virgo.
- ID:
- ivo://CDS.VizieR/J/ApJ/800/93
- Title:
- Wide field ugriz photometry of 0.06<z<0.4 AGNs
- Short Name:
- J/ApJ/800/93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry of the large-scale environments of a sample of 12 broad line active galactic nuclei (AGNs) with 0.06<z<0.37 from deep images in the Sloan Digital Sky Survey u, g, r, and i filters taken with the 90Prime prime focus camera on the Steward Observatory Bok Telescope. We measure galaxy clustering around these AGNs using two standard techniques: correlation amplitude (B_gq_) and the two point correlation function. We find average correlation amplitudes for the 10 radio-quiet objects in the sample equal to (9+/-18, 144+/-114, -39+/-56, 295+/-260)Mpc^1.77^ in (u, g, r, i), all consistent with the expectation from galaxy clustering. Using a ratio of the galaxy-quasar cross-correlation function to the galaxy autocorrelation function, we calculate the relative bias of galaxies and AGNs, b_gq_. The bias in the u band, b_gq_=3.08+/-0.51 is larger compared to that calculated in the other bands, but it does not correlate with AGN luminosity, black hole mass, or AGN activity via the luminosity of the [OIII] emission line. Thus ongoing nuclear accretion activity is not reflected in the large scale environments from ~10h^-1^kpc to ~0.5h^-1^Mpc and may indicate a non-merger mode of AGN activity and/or a significant delay between galaxy mergers and nuclear activity in this sample of mostly radio-quiet quasars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/2983
- Title:
- Wide low very low-mass binary systems
- Short Name:
- J/MNRAS/466/2983
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The frequency of multiple systems and their properties are key constraints of stellar formation and evolution. Formation mechanisms of very low-mass (VLM) objects are still under considerable debate, and an accurate assessment of their multiplicity and orbital properties is essential for constraining current theoretical models. Taking advantage of the virtual observatory capabilities, we looked for comoving low and VLM binary (or multiple) systems using the Large Area Survey of the UKIDSS LAS DR10, SDSS DR9 and the 2MASS Catalogues. Other catalogues (WISE, GLIMPSE, SuperCosmos, etc.) were used to derive the physical parameters of the systems. We report the identification of 36 low and VLM (~M0-L0 spectral types) candidates to binary/multiple system (separations between 200 and 92000au), whose physical association is confirmed through common proper motion, distance and low probability of chance alignment. This new system list notably increases the previous sampling in their mass-separation parameter space (~100). We have also found 50 low-mass objects that we can classify as ~L0-T2 according to their photometric information. Only one of these objects presents a common proper motion high-mass companion. Although we could not constrain the age of the majority of the candidates, probably most of them are still bound except four that may be under disruption processes. We suggest that our sample could be divided in two populations: one tightly bound wide VLM systems that are expected to last more than 10 Gyr, and other formed by weak bound wide VLM systems that will dissipate within a few Gyr.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A53
- Title:
- Wide-orbit companions to K-type stars in Sco-Cen
- Short Name:
- J/A+A/657/A53
- Date:
- 17 Mar 2022 14:41:58
- Publisher:
- CDS
- Description:
- The detection of low-mass companions to stellar hosts is important for testing the formation scenarios of these systems. Companions at wide separations are particularly intriguing objects as they are easily accessible for variability studies of the rotational dynamics and cloud coverage of these brown dwarfs or planetary-mass objects. We aim to identify new low-mass companions to young stars using the astrometric measurements provided by the Gaia space mission. When possible, we use high-contrast imaging data collected with VLT/SPHERE. We identified companion candidates from a sample of K-type, pre-main-sequence stars in the Scorpius Centaurus association using the early version of the third data release of the Gaia space mission. Based on the provided positions, proper motions, and magnitudes, we identified all objects within a predefined radius, whose differential proper motions are consistent with a gravitationally bound system. As the ages of our systems are known, we derived companion masses through comparison with evolutionary tracks. For seven identified companion candidates we used additional data collected with VLT/SPHERE and VLT/NACO to assess the accuracy of the properties of the companions based on Gaia photometry alone. We identify 110 comoving companions that have a companionship likelihood of more than 95%. Further color-magnitude analysis confirms their Sco-Cen membership. We identify ten especially intriguing companions that have masses in the brown dwarf regime down to 20M_{Jup}_. Our high-contrast imaging data confirm both astrometry and photometric masses derived from Gaia alone. We discovered a new brown dwarf companion, TYC 8252-533-1 B, with a projected separation of approximately 570au from its Sun-like primary. It is likely to be located outside the debris disk around its primary star and SED modeling of Gaia, SPHERE, and NACO photometry provides a companion mass of 52^+17^_-11_M_{Jup}_. We show that the Gaia database can identify low-mass companions at wide separations from their host stars. For K-type Sco-Cen members, Gaia can detect sub-stellar objects at projected separations larger than 300au and with a sensitivity limit beyond 1000 and a lower mass limit down to 20M_{Jup}_. A similar analysis of other star-forming regions could significantly enlarge the sample size of such objects and facilitate testing of the formation and evolution theories of planetary systems.
