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1281. Galactic globular clusters SDSS photometry
ID:
ivo://CDS.VizieR/J/MNRAS/437/1725
Title:
Galactic globular clusters SDSS photometry
Short Name:
J/MNRAS/437/1725
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present g' and z' aperture photometry for 96 Galactic globular clusters, making this the largest homogeneous catalogue of photometry for these objects in the Sloan Digital Sky Survey (SDSS) filter system. For a subset of 56 clusters, we also provide photometry in r' and i'. We carry out comparisons with previous photometry as well as with the SDSS data set. The data will be useful for a series of applications in Galactic and extragalactic astrophysics. Future papers will analyse the colour-metallicity relation, colour-magnitude diagrams and structural parameters. The compilation of results based on this data set will be collected in the Galactic Globular Cluster Catalog (G2C2).
1282. Galactic halo as seen by the CFHTLS
ID:
ivo://CDS.VizieR/J/ApJ/731/4
Title:
Galactic halo as seen by the CFHTLS
Short Name:
J/ApJ/731/4
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use Canada-France-Hawaii Telescope Legacy Survey data for 170deg^2^, recalibrated and transformed to the Sloan Digital Sky Survey ugri photometric system, to study the distribution of near-turnoff main-sequence stars in the Galactic halo along four lines of sight to heliocentric distances of ~35kpc. We find that the halo stellar number density profile becomes steeper at Galactocentric distances greater than R_gal_~28kpc, with the power-law index changing from n_inner_=-2.62+/-0.04 to n_outer_=-3.8+/-0.1. In particular, we test a series of single power-law models and find them to be strongly disfavored by the data. The parameters for the best-fit Einasto profile are n=2.2+/-0.2 and R_e_=22.2+/-0.4kpc. We measure the oblateness of the halo to be q=c/a=0.70+/-0.01 and detect no evidence of it changing across the range of probed distances. The Sagittarius stream is detected in the l=173{deg} and b=-62{deg} direction as an overdensity of [Fe/H]~-1.5dex stars at R_gal_~32kpc, providing a new constraint for the Sagittarius stream and dark matter halo models. We also detect the Monoceros stream as an overdensity of [Fe/H]>-1.5dex stars in the l=232{deg} and b=26{deg} direction at R_gal_<~25kpc. In the two sight lines where we do not detect significant substructure, the median metallicity is found to be independent of distance within systematic uncertainties ([Fe/H]~-1.5+/-0.1dex).
1283. Galactic halo RRab stars from CSS
ID:
ivo://CDS.VizieR/J/ApJ/763/32
Title:
Galactic halo RRab stars from CSS
Short Name:
J/ApJ/763/32
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present analysis of 12227 type-ab RR Lyraes (RRLs; ~9400 are newly discovered) found among the 200 million public light curves in Catalina Surveys Data Release 1. These stars span the largest volume of the Milky Way ever surveyed with RRLs, covering ~20000deg^2^ of the sky (0{deg}<{alpha}<360{deg}, -22{deg}<{delta}<65{deg}) to heliocentric distances of up to 60kpc. Each of the RRLs is observed between 60 and 419 times over a six-year period. Using period finding and Fourier fitting techniques we determine periods and apparent magnitudes for each source. We find that the periods are generally accurate to {sigma}=0.002% in comparison to 2842 previously known RRLs and 100 RRLs observed in overlapping survey fields. We photometrically calibrate the light curves using 445 Landolt standard stars and show that the resulting magnitudes are accurate to ~0.05mag using Sloan Digital Sky Survey (SDSS) data for ~1000 blue horizontal branch stars and 7788 RRLs. By combining Catalina photometry with SDSS spectroscopy, we analyze the radial velocity and metallicity distributions for >1500 of the RRLs. Using the accurate distances derived for the RRLs, we show the paths of the Sagittarius tidal streams crossing the sky at heliocentric distances from 20 to 60kpc. By selecting samples of Galactic halo RRLs, we compare their velocity, metallicity, and distance with predictions from a recent detailed N-body model of the Sagittarius system. We find that there are some significant differences between the distances and structures predicted and our observations.
1284. Galactic massive stars with AstraLux
ID:
ivo://CDS.VizieR/J/A+A/518/A1
Title:
Galactic massive stars with AstraLux
Short Name:
J/A+A/518/A1
Date:
21 Oct 2021
Publisher:
CDS
Description:
Massive stars have high-multiplicity fractions, and many of them have still undetected components, thus hampering the study of their properties. I study a sample of massive stars with high angular resolution to better characterize their multiplicity. I observed 138 fields that include at least one massive star with AstraLux, a lucky imaging camera at the 2.2m Calar Alto telescope. I also used observations of 3 of those fields with ACS/HRC on HST to obtain complementary information and to calibrate the AstraLux data. The results were compared with existing information from the Washington Double Star Catalog, Tycho-2, 2MASS, and other literature results.
1285. Galactic O star catalog
ID:
ivo://CDS.VizieR/V/116
Title:
Galactic O star catalog
Short Name:
V/116
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have produced a catalog of 378 Galactic O stars with accurate spectral classifications that is complete for V<8 but includes many fainter stars. The catalog provides cross-identifications with other sources; coordinates (obtained in most cases from Tycho-2 data); astrometric distances for 24 of the nearest stars; optical (Tycho-2, Johnson, and Stroemgren) and NIR photometry; group membership, runaway character, and multiplicity information; and a Web-based version with links to on-line services.
1286. Galactic O-type Stars
ID:
ivo://CDS.VizieR/II/82
Title:
Galactic O-type Stars
Short Name:
II/82
Date:
21 Oct 2021
Publisher:
CDS
Description:
The catalog is a compilation from the literature of all O-type stars for which spectral types, luminosity classes, and UBV photometry exist. The catalog contains 765 stars, for each of which designation (HD, DM, etc.), spectral type, V, B-V, absolute visual magnitude, absolute bolometric magnitude, cluster membership, distance, galactic coordinates, and source references are given. In addition, the authors have included derived values of absolute visual and bolometric magnitudes, and distances. The Catalog of Galactic O-Type Stars (Garmany, Conti and Chiosi 1982) is a compilation from the literature of all O-type stars for which spectral types, luminosity classes and UBV photometry exist. Most of the entries come from Cruz-Gonzalez, et al. (1974) and Humphreys (1978), with additional stars from Garrison and Kormendy (1976), Garrison, Hiltner and Schild (1977), Garrison and Schild (1979), Feinstein, Marraco and Muzzio (1973), Feinstein, Marraco and Forte (1976), and Moffat, FitzGerald and Jackson (1979).
1287. Galactic O-type stars from LAMOST spectra
ID:
ivo://CDS.VizieR/J/ApJS/253/54
Title:
Galactic O-type stars from LAMOST spectra
Short Name:
J/ApJS/253/54
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper reports 209 O-type stars found with LAMOST. All 135 new O-type stars discovered so far with LAMOST are given. Among them, 94 stars are first presented in this sample. There are 1 Iafpe star, 5 Onfp stars, 12 Oe stars, 1 Ofc stars, 3 ON stars, 16 double-lined spectroscopic binaries, and 33 single-lined spectroscopic binaries. All O-type stars are determined based on LAMOST low-resolution spectra (R~1800), with their LAMOST median-resolution spectra (R~7500) as supplements.
1288. Galactic outer disk: a field toward Tombaugh 1
ID:
ivo://CDS.VizieR/J/AJ/153/99
Title:
Galactic outer disk: a field toward Tombaugh 1
Short Name:
J/AJ/153/99
Date:
21 Oct 2021
Publisher:
CDS
Description:
We employ optical photometry and high-resolution spectroscopy to study a field toward the open cluster Tombaugh 1, where we identify a complex population mixture that we describe in terms of young and old Galactic thin disks. Of particular interest is the spatial distribution of the young population, which consists of dwarfs with spectral types as early as B6 and is distributed in a blue plume feature in the color-magnitude diagram. For the first time, we confirm spectroscopically that most of these stars are early-type stars and not blue stragglers or halo/thick-disk subdwarfs. Moreover, they are not evenly distributed along the line of sight but crowd at heliocentric distances between 6.6 and 8.2 kpc. We compare these results with present-day understanding of the spiral structure of the Galaxy and suggest that they trace the outer arm. This range of distances challenges current Galactic models adopting a disk cutoff at 14 kpc from the Galactic center. The young dwarfs overlap in space with an older component, which is identified as an old Galactic thin disk. Both young and old populations are confined in space since the disk is warped at the latitude and longitude of Tombaugh 1. The main effects of the warp are that the line of sight intersects the disk and entirely crosses it at the outer arm distance and that there are no traces of the closer Perseus arm, which would then be either unimportant in this sector or located much closer to the formal Galactic plane. Finally, we analyze a group of giant stars, which turn out to be located at very different distances and to possess very different chemical properties, with no obvious relation to the other populations.
1289. Galactic planetary nebulae with Gaia data
ID:
ivo://CDS.VizieR/J/ApJ/889/21
Title:
Galactic planetary nebulae with Gaia data
Short Name:
J/ApJ/889/21
Date:
21 Oct 2021
Publisher:
CDS
Description:
We matched the astrometry of central stars (CSs) of spectroscopically confirmed Galactic planetary nebulae (PNe) with DR2 Gaia parallaxes (p), finding 430 targets in common with p>0 and |{sigma}_p_/p|<1. A catalog of PNe whose CSs have DR2 Gaia parallaxes is presented in Table 1. We compared DR2 parallaxes with those in the literature, finding good correlation between the two samples. We used PNe parallaxes to calibrate the Galactic PN distance scale. Restricting the sample to objects with 20% parallax accuracy, we derive the distance scale log(R_pc_)=-(0.226+/-0.0155)xlog(S_H{beta}_)-(3.920+/-0.215), which represents a notable improvement with respect to previous ones. We found that the ionized mass versus optical thickness distance scale for Galactic PNe is not as constrained by the Gaia calibrators, but gives important insight into the nature of the PNe, and is essential to define the domain for our distance scale application. We placed the CSs whose distance has been determined directly by parallax on the HR diagram, and found that their location on the post-asymptotic-giant-branch (AGB) H-burning evolutionary tracks is typical for post-AGB stars.
1290. Galactic star clusters in SDSS. II. Colors.
ID:
ivo://CDS.VizieR/J/ApJ/700/523
Title:
Galactic star clusters in SDSS. II. Colors.
Short Name:
J/ApJ/700/523
Date:
21 Oct 2021
Publisher:
CDS
Description:
We perform an extensive test of theoretical stellar models for main-sequence (MS) stars in ugriz, using cluster fiducial sequences obtained in the previous paper of this series. We generate a set of isochrones using the Yale Rotating Evolutionary Code with updated input physics, and derive magnitudes and colors in ugriz from MARCS model atmospheres. These models match cluster MSs over a wide range of metallicity within the errors of the adopted cluster parameters. However, we find a large discrepancy of model colors at the lower MS (T_eff_<~4500K) for clusters at and above solar metallicity. We also reach similar conclusions using the theoretical isochrones of Girardi et al. and Dotter et al., but our new models are generally in better agreement with the data. Using our theoretical isochrones, we also derive MS-fitting distances and turnoff ages for five key globular clusters, and demonstrate the ability to derive these quantities from photometric data in the Sloan Digital Sky Survey. In particular, we exploit multiple color indices (g-r, g-i, and g-z) in the parameter estimation, which allows us to evaluate internal systematic errors. Our distance estimates, with an error of {sigma}_(m-M)_=0.03-0.11mag for individual clusters, are consistent with Hipparcos-based subdwarf-fitting distances derived in the Johnson-Cousins or Stromgren photometric systems.