- ID:
- ivo://CDS.VizieR/III/244
- Title:
- Catalog of Stellar Rotational Velocities
- Short Name:
- III/244
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a compilation of the observed projected rotational velocities, V_rot_*sin(i), for 28179 stars from 166 open clusters, globular clusters and associations. The catalog.dat file contains 39351 individual V_rot_*sin(i) data, together with the error and the method of determination. Because of the possible confusion with the use of different names for stars belonging to clusters we have included alternative names using SIMBAD nomenclature. Rotational velocities from CDS catalogue III/226 (Glebocki+ 2000) are included. Information about the number of stars in each cluster as well as other cluster names can be found in the "clusters.dat" file. The bibliographical references are provided in the "refs.dat" file. The file "mean.dat" contains mean V*sin(i) values for each star. The individual v*sin(i) measurements were reduced to a uniform standard (to remove the systematic errors) and a weighted average of V*sin(i) was calculated. The V*sin(i) values used as standards are presented in the "standards.dat" file.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/389/678
- Title:
- Catalogue of extended objects in Magellanic Clouds
- Short Name:
- J/MNRAS/389/678
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We update the Small Magellanic Cloud (SMC), Bridge and Large Magellanic Cloud (LMC) catalogues of extended objects that were constructed by members of our group from 1995 to 2000. In addition to the rich subsequent literature for the previous classes, we now also include HI shells and supershells. A total of 9305 objects were cross-identified, while our previous catalogues amounted to 7900 entries, an increase of ~12 per cent. We present the results in subcatalogues containing 1445 emission nebulae, 3740 star clusters, 3326 associations and 794 HI shells and supershells. Angular and apparent size distributions of the extended objects are analysed. We conclude that the objects, in general, appear to respond to tidal effects arising from the LMC, SMC and Bridge. Number-density profiles extracted along directions parallel and perpendicular to the LMC bar, can be described by two exponential-discs. A single exponential-disc fits the equivalent SMC profiles. Interestingly, when angular-averaged number-densities of most of the extended objects are considered, the profiles of both Clouds do not follow an exponential-disc. Rather, they are best described by a tidally truncated, core/halo profile, despite the fact that the Clouds are clearly disturbed discs. On the other hand, the older star clusters taken isolately, distribute as an exponential disc. The present catalogue is an important tool for the unambiguous identification of previous objects in current CCD surveys and to establish new findings.
- ID:
- ivo://CDS.VizieR/J/MNRAS/425/3085
- Title:
- CCD CT1 data of stars in the field of B119
- Short Name:
- J/MNRAS/425/3085
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present for the first time Washington CT_1_ photometry for 11 unstudied or poorly studied candidate star clusters. The selected objects are of small angular size, contain a handful of stars, and are projected towards the innermost regions of the Small Magellanic Cloud (SMC). The respective colour-magnitude diagrams (CMDs) were cleaned of the unavoidable star field contamination by taking advantage of a procedure which makes use of variable size CMD cells. This method has shown to be able to eliminate stochastic effects in the cluster CMDs caused by the presence of isolated bright stars, as well as to make a finer cleaning in the most populous CMD regions. Our results suggest that nearly one-third of the studied candidate star clusters would appear to be genuine physical systems.
- ID:
- ivo://CDS.VizieR/J/AJ/144/100
- Title:
- CCD Washington CT1T2 photometry of stars in LMC
- Short Name:
- J/AJ/144/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry for an unprecedented database of some 5.5million stars distributed throughout the Large Magellanic Cloud main body, from 21 fields covering a total area of 7.6deg^2^, obtained from Washington CT_1_T_2_ CTIO 4m MOSAIC data. Extensive artificial star tests over the whole mosaic image data set and the observed behavior of the photometric errors with magnitude demonstrate the accuracy of the morphology and clearly delineate the position of the main features in the color-magnitude diagrams (CMDs). The representative T_1_(MS TO) mags are on average ~0.5mag brighter than the T_1_ mags for the 100% completeness level of the respective field, allowing us to derive an accurate age estimate. We have analyzed the CMD Hess diagrams and used the peaks in star counts at the main sequence turnoff and red clump (RC) locations to age date the most dominant sub-population (or "representative" population) in the stellar population mix. The metallicity of this representative population is estimated from the locus of the most populous red giant branch track. We use these results to derive age and metallicity estimates for all of our fields. The analyzed fields span age and metallicity ranges covering most of the galaxy's lifetime and chemical enrichment, i.e., ages and metallicities between ~1 and 13Gyr and ~-0.2 and -1.2dex, respectively. We show that the dispersions associated with the mean ages and metallicities represent in general a satisfactory estimate of the age/metallicity spread (~1-3 Gyr/0.2-0.3 dex), although a few subfields have a slightly larger age/metallicity spread. Finally, we revisit the study of the vertical structure (VS) phenomenon, a striking feature composed of stars that extend from the bottom, bluest end of the RC to ~0.45mag fainter. We confirm that the VS phenomenon is not clearly seen in most of the studied fields and suggest that its occurrence is linked to some other condition(s) in addition to the appropriate age, metallicity, and the necessary red giant star density.
- ID:
- ivo://CDS.VizieR/J/ApJ/720/1674
- Title:
- CFHT M33 extended sources catalog
- Short Name:
- J/ApJ/720/1674
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 2990 extended sources in a 1x1{deg} area centered on M33 using the MegaCam camera on the 3.6m Canada-France-Hawaii Telescope. The catalog includes 599 new candidate stellar clusters, 204 previously confirmed clusters, 1969 likely background galaxies, and 218 unknown extended objects. We present ugriz integrated magnitudes of the candidates and confirmed star clusters (SCs) as well as the full width at half maximum, ellipticity, and stellarity. Based on the properties of the confirmed SCs, we select a sub-sample of highly probable clusters composed of 246 objects. The integrated photometry of the complete cluster catalog reveals a wide range of colors of -0.4<(g-r)<1.5 and -1.0<(r-i)<1.0 with no obvious cluster subpopulations. Comparisons with models of simple stellar populations suggest a large range of ages some as old as ~10Gyr.
- ID:
- ivo://CDS.VizieR/J/A+A/646/A46
- Title:
- Chamaeleon DANCe. Stellar population with Gaia-DR2
- Short Name:
- J/A+A/646/A46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Kinematic properties and stellar parameters of the Chamaeleon stars selected in our membership analysis using Gaia-DR2 data. We provide for each star its identifier, position, proper motion, parallax, radial velocity, distance, spatial velocity, SED classification, age and membership probability. We also provide the membership probabilities for all sources in the fields surveyed by our study and the empirical isochrone of the Cha I and Cha II subgroups.
- ID:
- ivo://CDS.VizieR/J/ApJ/602/816
- Title:
- Chamaeleon I star-forming region census
- Short Name:
- J/ApJ/602/816
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I present a new census of the members of the Chamaeleon I star-forming region. Optical spectroscopy has been obtained for 179 objects that have been previously identified as possible members of the cluster, that lack either accurate spectral types or clear evidence of membership, and that are optically visible (I<~18). I have used these spectroscopic data and all other available constraints to evaluate the spectral classifications and membership status of a total sample of 288 candidate members of Chamaeleon I that have appeared in published studies of the cluster. The latest census of Chamaeleon I now contains 158 members, eight of which are later than M6 and thus are likely to be brown dwarfs. I find that many of the objects identified as members of Chamaeleon I in recent surveys are actually field stars. Meanwhile, seven of nine candidates discovered by Carpenter and coworkers are confirmed as members, one of which is the coolest known member of Chamaeleon I at a spectral type of M8 (~0.03M_{sun}_). I have estimated extinctions, luminosities, and effective temperatures for the members and used these data to construct an H-R diagram for the cluster. Chamaeleon I has a median age of ~2Myr according to evolutionary models and hence is similar in age to IC 348 and is slightly older than Taurus (~1Myr). The measurement of an initial mass function for Chamaeleon I from this census is not possible because of the disparate methods with which the known members were originally selected and must await an unbiased, magnitude-limited survey of the cluster.
- ID:
- ivo://CDS.VizieR/J/A+A/464/211
- Title:
- Chandra and near-IR obs. of Cyg OB2
- Short Name:
- J/A+A/464/211
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this work is to identify the so far unknown low mass stellar population of the ~2Myr old Cygnus OB2 star forming region, and to investigate the X-ray and near-IR stellar properties of its members. We analyzed a 97.7ks Chandra ACIS-I observation pointed at the core of the Cygnus OB2 region. Sources were detected using the PWDETECT code and were positionally correlated with optical and near- IR catalogs from the literature. Source events were extracted with the Acis E XTRACT package. X-ray variability was characterized through the Kolmogorov-Smirnov test and spectra were fitted using absorbed thermal plasma models. We detected 1003 X-ray sources. Of these, 775 have near-IR counterparts and are expected to be almost all associated with Cygnus OB2 members.
- ID:
- ivo://CDS.VizieR/J/A+A/463/275
- Title:
- Chandra obs. of Serpens star-forming region
- Short Name:
- J/A+A/463/275
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To study the properties of X-ray emission from young stellar objects (YSOs) through their evolution from Class I to Class III and determine whether Class 0 protostars emit X-rays. A deep Chandra X-ray observation of the Serpens star-forming region was obtained. The Serpens Cloud Core is ideally suited for this type of investigation, being populated by a dense and extremely young cluster whose members are found in all evolutionary stages, including six well-studied Class 0 sources.
- ID:
- ivo://CDS.VizieR/J/ApJS/194/11
- Title:
- Chandra study of Trumpler 15 in Carina
- Short Name:
- J/ApJS/194/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the highest-resolution X-ray observation of the Trumpler 15 star cluster taken by the Chandra X-ray Observatory, we estimate the total size of its stellar population by comparing the X-ray luminosity function (XLF) of the detected sources to a calibrator cluster and identify for the first time a significant fraction (~14%) of its individual members. The highest-resolution near-IR observation of Trumpler 15 (taken by the HAWK-I instrument on the Very Large Telescope) was found to detect most of our X-ray selected sample of cluster members, with a K-excess disk frequency of 3.8%+/-0.7%. The near-IR data, XLF, and published spectral types of the brightest members support a cluster age estimate (5-10Myr) that is older than those for the nearby Trumpler 14 and Trumpler 16 clusters, and suggest that high-mass members may have already exploded as supernovae. The morphology of the inner ~0.7pc core of the cluster is found to be spherical. However, the outer regions (beyond ~2pc) are elongated, forming an "envelope" of stars that, in projection, appears to connect Trumpler 15 to Trumpler 14; this morphology supports the view that these clusters are physically associated. Clear evidence of mass segregation is seen. This study appears in this special issue devoted to the Chandra Carina Complex Project, a 1.42deg^2^ Chandra X-ray survey of the Great Nebula in Carina.
