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861. Synthetic Stroemgren photometry
ID:
ivo://CDS.VizieR/J/AJ/127/1227
Title:
Synthetic Stroemgren photometry
Short Name:
J/AJ/127/1227
Date:
21 Oct 2021
Publisher:
CDS
Description:
A new grid of theoretical color indices for the Stroemgren uvby photometric system has been derived from MARCS model atmospheres and SSG synthetic spectra for cool dwarf and giant stars having -3.0<=[Fe/H]<=+0.5 and 3000<=T_eff_<=8000K. In the present investigation, we have also analyzed the observed Stroemgren photometry for the classic Population II subdwarfs, compared our "final" (b-y)-Teff relationship with those derived empirically in a number of recent studies and examined in some detail the dependence of the m1 index on [Fe/H].
862. T1C photometry of NGC7507
ID:
ivo://CDS.VizieR/J/A+A/555/A56
Title:
T1C photometry of NGC7507
Short Name:
J/A+A/555/A56
Date:
21 Oct 2021
Publisher:
CDS
Description:
There is strong evidence that globular cluster systems (GCSs) of massive galaxies are largely assembled by infall/accretion processes. Therefore, we expect the GCSs of isolated elliptical galaxies to be poor. Although not completely isolated, NGC 7507 is a massive field elliptical galaxy with an apparently very low dark matter content. We determine the richness, the colour distribution, and the structural properties of the GCS of NGC 7507. We performed wide-field Washington photometry with data obtained with the MOSAIC II camera at the 4m-Blanco telescope (CTIO, Chile).
863. Terzan 5 chemical and kinematical properties
ID:
ivo://CDS.VizieR/J/ApJ/791/101
Title:
Terzan 5 chemical and kinematical properties
Short Name:
J/ApJ/791/101
Date:
21 Oct 2021
Publisher:
CDS
Description:
As part of a study aimed at determining the kinematical and chemical properties of Terzan 5, we present the first characterization of the bulge stars surrounding this puzzling stellar system. We observed 615 targets located well beyond the tidal radius of Terzan 5 and found that their radial velocity distribution is well described by a Gaussian function peaked at <v_rad_> = +21.0+/-4.6 km/s with dispersion {sigma}_v_= 113.0+/-2.7 km/s. This is one of the few high-precision spectroscopic surveys of radial velocities for a large sample of bulge stars in such a low and positive latitude environment (b = +1.7{deg}). We found no evidence of the peak at <v_rad_> ~ +200 km/s found in Nidever et al. (2012ApJ...755L..25N). Strong contamination of many observed spectra by TiO bands prevented us from deriving the iron abundance for the entire spectroscopic sample, introducing a selection bias. The metallicity distribution was finally derived for a subsample of 112 stars in a magnitude range where the effect of the selection bias is negligible. The distribution is quite broad and roughly peaked at solar metallicity ([Fe/H] =~ +0.05 dex) with a similar number of stars in the super-solar and in the sub-solar ranges. The population number ratios in different metallicity ranges agree well with those observed in other low-latitude bulge fields, suggesting (1) the possible presence of a plateau for|b| < 4{deg} in the ratio between stars in the super-solar (0 < [Fe/H] <0.5 dex) and sub-solar (-0.5 < [Fe/H] <0 dex) metallicity ranges; (2) a severe drop in the metal-poor component ([Fe/H] <-0.5) as a function of Galactic latitude.
864. Terzan 10, ESO456-SC38 and UKS 1 VIz photometry
ID:
ivo://CDS.VizieR/J/A+AS/126/319
Title:
Terzan 10, ESO456-SC38 and UKS 1 VIz photometry
Short Name:
J/A+AS/126/319
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present optical colour-magnitude diagrams for the faint bulge globular clusters Terzan 10, ESO456-SC38 and UKS 1. The giant branches are detected but the horizontal branch is near the observational cutoff for the former two clusters and is not detected in UKS 1. We provide estimates of metallicity, reddening and distance for these clusters, some of these values determined for the first time.
865. Terzan 6 NTT VI photometry
ID:
ivo://CDS.VizieR/J/A+AS/122/483
Title:
Terzan 6 NTT VI photometry
Short Name:
J/A+AS/122/483
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present for the first time optical (V, I and Gunn z) colour magnitude diagrams for Terzan 6, which were collected under excellent seeing conditions with the ESO NTT telescope. The horizontal branch morphology is red, nearly superimposed on the red giant branch. The red giant branch morphology presents characteristics intermediate between those of 47 Tuc and NGC 6528/NGC 6553. We derive a reddening of E(B-V)=2.24 and a distance d_{sun}_=7.0kpc (assuming R=3.1). We conclude that Terzan 6 belongs to the metal-rich bulge globular cluster system.
866. Terzan 2 VI photometry
ID:
ivo://CDS.VizieR/J/A+A/326/614
Title:
Terzan 2 VI photometry
Short Name:
J/A+A/326/614
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present for the first time optical colour magnitude diagrams of the globular cluster Terzan 2, in the V, I colours. The horizontal branch is red. The red giant branch morphology can be fitted with that of 47 Tuc, but definitely not th at of NGC 6553. We derive a reddening of E(B-V)=1.54 and a distance d_{sun}_=7.7kpc if R=3.1, or 5.3kpc if R=3.6. Terzan 2 adds to the list of bulge metal-rich clusters now with reliable parameters.
867. The ages of M31 star clusters: SED versus CMD
ID:
ivo://CDS.VizieR/J/AJ/156/191
Title:
The ages of M31 star clusters: SED versus CMD
Short Name:
J/AJ/156/191
Date:
21 Oct 2021
Publisher:
CDS
Description:
It is well-known that fitting Color-Magnitude Diagrams (CMDs) to theoretical isochrones is the main method to determine star cluster ages. However, when CMDs are not available, the Spectral Energy Distribution (SED)-fitting technique is the only other approach, although it suffers the age-metallicity-reddening degeneracy. In this work, we gather the ages, metallicities, and masses of dozens of M31 star clusters from the CMD-fitting with Hubble Space Telescope images from the literature for comparison. We check the reliability of the SED-fitting results with different models, i.e., Bruzual & Charlot (2003MNRAS.344.1000B) model (BC03), Galaxy Evolutionary Synthesis Models (GALEV), and Advanced Stellar Population Synthesis (ASPS) for the simple stellar populations (SSPs) with single stars (ss)-SSP/binary-star (bs)-SSPs models. The photometry bands includes the Galaxy Evolution Explorer GALEX FUV/NUV bands, optical/near-infrared UBVRIJHK bands, as well as the Wide-field Infrared Survey Explorer (WISE) W1/W2 bands. The comparisons show that the SED-fitting ages agree well with the CMD-fitting ages, either with the fixed metallicity or with the free metallicity for both the BC03 and the GALEV model. However, for the ASPS models, it seems that SED-fitting results are systematically older than the CMD ages, especially for the ages log t<9.0 (year). The fitting also shows that the GALEX FUV/NUV-band are more important than the WISE W1/W2 for constraining the ages, which confirms the previous findings. We also derived the masses of our sample star clusters from the BC03 and GALEV models and it is found that the values agree well with those in the literature.
868. The Cluster System of the LMC
ID:
ivo://CDS.VizieR/VII/183
Title:
The Cluster System of the LMC
Short Name:
VII/183
Date:
21 Oct 2021
Publisher:
CDS
Description:
A new catalogue of clusters in the Large Magellanic Cloud has been constructed from searches of the IIIa-J component of the ESO/SERC Southern Sky Atlas. The catalogue contains coordinate and diameter measurements of 1762 clusters in a 25x25{deg} area of sky centred on the LMC, but excluding the very crowded 3.5 square deg. region around the Bar. The distribution of these clusters appears as two superimposed elliptical systems. The higher density inner system extends over about 8d; the lower density outer system can be represented by 13d X 10d disc inclined at 42d to the line of sight. There are suggestions of two weak "arms" in the latter.
869. The Core of NGC 6624
ID:
ivo://CDS.VizieR/J/AJ/109/639
Title:
The Core of NGC 6624
Short Name:
J/AJ/109/639
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used the Faint Object Camera on the Hubble Space Telescope (HST) to observe three fields near the center of the post-collapse globular cluster NGC 6624 in B and V. We use individual stellar positions and a maximum-likelihood technique to measure a position for the cluster center. We then transfer this position and the position of the x-ray source 4U 1820-30 to right ascension and declination, and correct an error of 1.8" in an earlier paper. From star counts, we obtain a density profile, with a power-law cusp of slope -0.84 +/- 0.16. No flat core is evident. We construct color-magnitude diagrams down to the main-sequence turnoff near the cluster center, and more than three magnitudes below the turnoff in the outermost field at r=28". The former diagram reveals a central population of blue stragglers, which has not previously been observed in this cluster. These blue stragglers are quite similar in specific frequency to those recently observed by HST in the core of 47 Tuc, and their presence adds to the growing evidence of stellar interactions in dense globular-cluster cores.
870. The Fornax Deep Survey with the VST. IX.
ID:
ivo://CDS.VizieR/J/A+A/639/A136
Title:
The Fornax Deep Survey with the VST. IX.
Short Name:
J/A+A/639/A136
Date:
21 Oct 2021
Publisher:
CDS
Description:
A possible pathway for understanding the events and the mechanisms involved in galaxy formation and evolution is an in-depth comprehension of the galactic and inter-galactic fossil sub-structures with long dynamical times-scales: stars in the field and in stellar clusters. This paper continues the series of the Fornax Deep Survey (FDS). Following the previous studies dedicated to extended Fornax cluster members, in this paper we present the catalogs of compact stellar systems in the Fornax cluster as well as extended background sources and point-like sources. We derive ugri photometry of ~1.7 million sources over the ~21 square degree area of FDS centered on the bright central galaxy NGC1399. For a wider area, of ~27 square degrees extending in the direction of NGC1316, we provide gri photometry for ~3.1 million sources. To improve the morphological characterization of sources we generate multi-band image stacks by coadding the best seeing gri-band single exposures with a cut at FWHM<=0.9". We use the multi-band stacks as master detection frames, with a FWHM improved by ~15% and a FWHM variability from field to field reduced by a factor of ~2.5 compared to the pass-band with best FWHM, namely the r-band. The identification of compact sources, in particular of globular clusters (GC), is obtained from a combination of photometric (e.g. colors, magnitudes) and morphometric (e.g. concentration index, elongation, effective radius) selection criteria, by also taking as reference the properties of sources with well-defined classification from spectroscopic or high-resolution imaging data. Using the FDS catalogs, we present a preliminary analysis of globular cluster (GC) distributions in the Fornax area. The study confirms and extends further previous results which were limited to a smaller survey area. We observe the inter-galactic population of GCs, a population of mainly blue GCs centered on NGC1399, extends over ~0.9Mpc, with an ellipticity ~0.65 and a small tilt in the direction of NGC1336. Several sub-structures extend over ~0.5Mpc along various directions. Two of these structures do not cross any bright galaxy; one of them appears to be connected to NGC1404, a bright galaxy close to the cluster core and particularly poor of GCs. Using the gri catalogs we analyze the GC distribution over the extended FDS area, and do not find any obvious GC sub-structure bridging the two brightest cluster galaxies, NGC1316 and NGC1399. Although NGC1316 is more than twice brighter of NGC1399 in optical bands, using gri data, we estimate a factor of ~3-4 richer GC population around NGC1399 compared to NGC1316, out to galactocentric distances of ~40' or ~230kpc

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