Search

Start Over Subject galaxies Content Level Research
3511. Star clusters, associations, & candidates in the MW
ID:
ivo://CDS.VizieR/J/AJ/157/12
Title:
Star clusters, associations, & candidates in the MW
Short Name:
J/AJ/157/12
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of Galactic star clusters, associations and candidates with 10978 entries. This multi-band catalog was constructed over 20 years, starting with visual inspections on the Digital Sky Survey and incremented with the 2MASS, WISE, VVV, Spitzer, and Herschel surveys. Large and small catalogs, as well as papers on individual objects have been systematically cross-identified. The catalog provides Galactic and equatorial coordinates, angular diameters, and chronologically ordered designations, making it simple to assign discoveries and verify how often the objects were cataloged by different authors, search methods, and/or surveys. Detection in a single band is the minimum constraint to validate an entry. About 3200 objects have measured parameters in the literature. A fundamental contribution of the present study is to present an additional ~7700 objects for the first analyses of nature, photometry, spectroscopy and structure. The present focus is not to compile or determine fundamental parameters, but to provide a catalog uniformly characterizing the entries. A major result is that now 4234 embedded clusters are cataloged, a factor of ~1.5 larger than open clusters. In addition to cross-identifications in different references and wavelength domains, we also communicate the discovery of 638 star clusters and similar objects. The present general catalog provides previously studied objects and thousands of additional entries in a homogeneous way, a timely contribution to Gaia-related works.
3512. Star clusters in IC 10
ID:
ivo://CDS.VizieR/J/ApJ/804/123
Title:
Star clusters in IC 10
Short Name:
J/ApJ/804/123
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a survey of star clusters in the halo of IC 10, a starburst galaxy in the Local Group, based on Subaru R-band images and NOAO Local Group Survey UBVRI images. We find five new star clusters. All of these star clusters are located far from the center of IC 10, while previously known star clusters are mostly located in the main body. Interestingly, the distribution of these star clusters shows an asymmetrical structure elongated along the east and southwest directions. We derive UBVRI photometry of 66 star clusters, including these new star clusters, as well as previously known star clusters. Ages of the star clusters are estimated from a comparison of their UBVRI spectral energy distribution with the simple stellar population models. We find that the star clusters in the halo are all older than 1Gyr, while those in the main body have various ages, from very young (several Myr) to old (>1Gyr). The young clusters (<10Myr) are mostly located in the H{alpha} emission regions and are concentrated on a small region at 2" in the southeast direction from the galaxy center, while the old clusters are distributed in a wider area than the disk. Intermediate-age clusters (~100 Myr) are found in two groups. One is close to the location of the young clusters and the other is at ~ 4" from the location of the young clusters. The latter may be related to past mergers or tidal interaction.
3513. Star clusters in IC 10
ID:
ivo://CDS.VizieR/J/PAZh/35/829
Title:
Star clusters in IC 10
Short Name:
J/PAZh/35/829
Date:
21 Oct 2021
Publisher:
CDS
Description:
Based on our observations with the 6-m BTA telescope at the Special Astrophysical Observatory, the Russian Academy of Sciences, and archival Hubble Space Telescope images, we have performed stellar photometry for several regions of the irregular galaxy IC 10, a member of the Local Group. Distance moduli with a median value of m-M=24.47, D=780+/-4kpc, have been obtained by the TRGB method for several regions of IC 10. We have revealed 57 star clusters with various masses and ages within the fields used. Comparison of the Hertzsprung-Russell diagrams for star clusters in IC 10 with theoretical isochrones has shown that this galaxy has an enhanced metallicity, which probably explains the high ratio of the numbers of carbon and nitrogen Wolf-Rayet stars (WC/WN). The size of the galaxy's thick disk along its minor axis is 10.5' and a more extended halo is observed outside this disk.
3514. Star Clusters in M33
ID:
ivo://CDS.VizieR/J/ApJS/122/431
Title:
Star Clusters in M33
Short Name:
J/ApJS/122/431
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper we present the discovery of 60 star clusters in 20 multiband Hubble Space Telescope (HST) WFPC2 fields in M33. The fields sample a variety of environments, from outer regions to spiral arms and central regions, as well as a range of galactocentric distances. The HST spatial resolution allowed us to penetrate the crowded, spiral arm regions of M33 yielding the first unbiased, representative sample of star clusters for this galaxy. We discuss the separation of clusters from stellar sources, and from other extended sources such as star-forming regions, H II regions, and supernova remnants. For the clusters we present multiband images and discuss morphology, location, and integrated photometry. Measured cluster colors and magnitudes are presented. The cluster density in our sample as a function of galactocentric distance yields an estimate of 690 total clusters in M33.
3515. Star clusters in M31
ID:
ivo://CDS.VizieR/J/ApJS/177/174
Title:
Star clusters in M31
Short Name:
J/ApJS/177/174
Date:
21 Oct 2021
Publisher:
CDS
Description:
A new survey of star clusters in the southwest field of the M31 disk based on the high-resolution Subaru Suprime-Cam observations is presented. The UBVRI aperture CCD photometry catalog of 285 objects (V<~20.5mag; 169 of them identified for the first time) is provided. Each object is supplemented with multiband color maps presented in the electronic edition of the Astrophysical Journal Supplement. Seventy-seven star cluster candidates from the catalog are located in the Hubble Space Telescope archive frames.
3516. Star clusters in M33
ID:
ivo://CDS.VizieR/J/MNRAS/451/3400
Title:
Star clusters in M33
Short Name:
J/MNRAS/451/3400
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present precision radial velocities and stellar population parameters for 77 star clusters in the Local Group galaxy M33. Our Gran Telescopio de Canarias and William Herschel Telescope observations sample both young, massive clusters and known/candidate globular clusters (GCs), spanning ages ~10^6-10^10yr, and metallicities, [M/H]~-1.7 to solar. The cluster system exhibits an age-metallicity relation; the youngest clusters are the most metal rich. When compared to HI data, clusters with [M/H]~-1.0 and younger than ~4Gyr are clearly identified as a disc population. The clusters show evidence for strong time evolution in the disc radial metallicity gradient (d[M/H]dt/dR=0.03dex/kpc/Gyr). The oldest clusters have stronger, more negative gradients than the youngest clusters in M33. The clusters also show a clear age-velocity dispersion relation. The line-of-sight velocity dispersions of the clusters increases with age similar to Milky Way open clusters and stars. The general shape of the relation is reproduced by disc heating simulations, and the similarity between the relations in M33 and the Milky Way suggests that heating by substructure and cooling of the interstellar medium both play a role in shaping this relation. We identify 12 'classical' GCs, six of which are newly identified GC candidates. The GCs are more metal rich than Milky Way halo clusters, and show weak rotation. The inner (R<4.5kpc) GCs exhibit a steep radial metallicity gradient (d[M/H]/dR=-0.29+/-0.11dex/kpc) and an exponential-like surface density profile. We argue that these inner GCs are thick disc rather than halo objects.
3517. Star clusters in M31
ID:
ivo://CDS.VizieR/J/AJ/137/94
Title:
Star clusters in M31
Short Name:
J/AJ/137/94
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an updated catalog of 1300 objects in the field of M31, including 670 likely star clusters of various types, the rest being stars or background galaxies once thought to be clusters. The coordinates in the catalog are accurate to 0.2", and are based on images from the Local Group Survey (LGS) or from the Digitized Sky Survey (DSS). Archival Hubble Space Telescope (HST) images and the LGS were inspected to confirm cluster classifications where possible, but most of the classifications are based on spectra taken of ~1000 objects with the Hectospec fiber positioner and spectrograph on the 6.5m MMT.
3518. Star clusters in M31. II.
ID:
ivo://CDS.VizieR/J/AJ/141/61
Title:
Star clusters in M31. II.
Short Name:
J/AJ/141/61
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new high signal-to-noise spectroscopic data on the M31 globular cluster (GC) system, obtained with the Hectospec multifiber spectrograph on the 6.5m MMT. More than 300 clusters have been observed at a resolution of 5{AA} and with a median S/N of 75 per{AA}, providing velocities with a median uncertainty of 6km/s. The primary focus of this paper is the determination of mean cluster metallicities, ages, and reddenings. Metallicities were estimated using a calibration of Lick indices with [Fe/H] provided by Galactic GCs.
3519. Star clusters in M31. VII. Globular clusters RVs
ID:
ivo://CDS.VizieR/J/ApJ/824/42
Title:
Star clusters in M31. VII. Globular clusters RVs
Short Name:
J/ApJ/824/42
Date:
21 Oct 2021
Publisher:
CDS
Description:
We carry out a joint spatial-kinematical-metallicity analysis of globular clusters (GCs) around the Andromeda Galaxy (M31), using a homogeneous, high-quality spectroscopic data set. In particular, we remove the contaminating young clusters that have plagued many previous analyses. We find that the clusters can be divided into three major metallicity groups based on their radial distributions: (1) an inner metal-rich group ([Fe/H]>-0.4); (2) a group with intermediate metallicity (with median [Fe/H]=-1); and (3) a metal-poor group, with [Fe/H]. The metal-rich group has kinematics and spatial properties like those of the disk of M31, while the two more metal-poor groups show mild prograde rotation overall, with larger dispersions --in contrast to previous claims of stronger rotation. The metal-poor GCs are the least concentrated group; such clusters occur five times less frequently in the central bulge than do clusters of higher metallicity. Despite some well-known differences between the M31 and Milky Way GC systems, our revised analysis points to remarkable similarities in their chemodynamical properties, which could help elucidate the different formation stages of galaxies and their GCs. In particular, the M31 results motivate further exploration of a metal-rich GC formation mode in situ, within high-redshift, clumpy galactic disks.
3520. Star clusters in NGC 3256
ID:
ivo://CDS.VizieR/J/MNRAS/405/857
Title:
Star clusters in NGC 3256
Short Name:
J/MNRAS/405/857
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper we derive ages and masses for 276 clusters in the merger galaxy NGC 3256. This was achieved by taking accurate photometry in four wavebands from archival Hubble Space Telescope images. Photometric measurements are compared to synthetic stellar population (SSP) models to find the most probable age, mass and extinction. The cluster population of NGC 3256 reveals an increase in the star formation rate (SFR) over the last 100Myr and the initial cluster mass function (ICMF) is best described by a power-law relation with slope alpha=1.85+/-0.12.