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1001. Globular clusters in NGC 5128
ID:
ivo://CDS.VizieR/J/ApJS/150/367
Title:
Globular clusters in NGC 5128
Short Name:
J/ApJS/150/367
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a photometric and spectroscopic survey of the globular cluster (GC) system of NGC 5128 (Centaurus A), a galaxy whose proximity makes it an important target for early-type galaxy studies. We imaged three fields in UBVRI that extend 50 and 30kpc along the major and minor axes, respectively. We used both color and size information to develop efficient selection criteria for differentiating between star clusters and foreground stars. In total, we obtained new velocities for 138 globular clusters, nearly tripling the number of known clusters, and bringing the confirmed total in NGC 5128 to 215. We present a full catalog of all known GCs, with their positions, photometry, and velocities. In addition, we present catalogs of other objects observed, such as foreground stars, background galaxies, three Galactic white dwarfs, seven background QSOs, and 52 optical counterparts to known X-ray point sources. We also report an observation of the cluster [HGH92] G169, in which we confirm the existence of a bright emission line object. This object, however, is unlikely to be a planetary nebula, but may be a supernova remnant.
1002. Globular clusters in NGC 474 from CFHT obs.
ID:
ivo://CDS.VizieR/J/ApJ/835/123
Title:
Globular clusters in NGC 474 from CFHT obs.
Short Name:
J/ApJ/835/123
Date:
21 Oct 2021
Publisher:
CDS
Description:
Globular clusters (GCs) are some of the most visible tracers of the merging and accretion histories of galaxy halos. Metal-poor GCs, in particular, are thought to arrive in massive galaxies largely through dry, minor merging events, but it is rare to see a direct connection between GCs and visible stellar streams. NGC 474 is a post-merger early-type galaxy with dramatic fine structures made of concentric shells and radial streams that have been more clearly revealed by deep imaging. We present a study of GCs in NGC 474 to better establish the relationship between merger-induced fine structure and the GC system. We find that many GCs are superimposed on visible streams and shells, and about 35% of GCs outside 3R_e,galaxy_ are located in regions of fine structure. The spatial correlation between GCs and fine structure is significant at the 99.9% level, which shows that this correlation is not coincidental. The colors of GCs on fine structures are mostly blue, and we also find an intermediate-color population that is dominant in the central region and that will likely passively evolve to have colors consistent with a traditional metal-rich GC population. The association of the blue GCs with fine structures is direct confirmation that many metal-poor GCs are accreted onto massive galaxy halos through merging events and that the progenitors of these mergers are sub-L^*^ galaxies.
1003. Globular clusters in Sculptor group
ID:
ivo://CDS.VizieR/J/AJ/127/2674
Title:
Globular clusters in Sculptor group
Short Name:
J/AJ/127/2674
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use CTIO 4m Mosaic II images taken with the Washington CM and Harris R filters to identify candidate globular clusters in the six major galaxies of the Sculptor group: NGC 45, 55, 247, 254, 300, and 7793. From follow-up spectroscopy with Hydra-CTIO, we find 19 new globular clusters in NGC 55, 247, 253, and 300, bringing the total number of known Sculptor group globular clusters to 36. The newly discovered clusters have spectroscopic ages consistent with those of old Milky Way globular clusters, and the majority are metal-poor.
1004. 4 globular clusters RGB and AGB stars
ID:
ivo://CDS.VizieR/J/A+A/603/A37
Title:
4 globular clusters RGB and AGB stars
Short Name:
J/A+A/603/A37
Date:
21 Oct 2021
Publisher:
CDS
Description:
Spectroscopic studies have demonstrated that nearly all Galactic globular clusters (GCs) harbour multiple stellar populations with different chemical compositions. Moreover, colour-magnitude diagrams based exclusively on Stroemgrem photometry have allowed us to identify and characterise multiple populations along the RGB of a large number of clusters. In this paper we show for the first time that Stroemgren photometry is also very efficient at identifying multiple populations along the AGB, and demonstrate that the AGB of M3, M92, NGC362, NGC1851, and NGC6752 are not consistent with a single stellar population. We also provide a catalogue of RGB and AGB stars photometrically identified in these clusters for further spectroscopic follow-up studies. We combined photometry and elemental abundances from the literature for RGB and AGB stars in NGC6752 where the presence of multiple populations along the AGB has been widely debated. We find that, while the MS, SGB, and RGB host three stellar populations with different helium and light element abundances, only two populations of AGB stars are present in the cluster. These results are consistent with standard evolutionary theory.
1005. Globular cluster system in M87
ID:
ivo://CDS.VizieR/J/ApJ/559/812
Title:
Globular cluster system in M87
Short Name:
J/ApJ/559/812
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a comprehensive database of kinematic, photometric, and positional information for 352 objects in the field of M87 (NGC 4486), the central giant elliptical galaxy in the Virgo Cluster; the majority of the tracers are globular clusters associated with that galaxy. New kinematic information comes from multislit observations with the Multi-Object Spectrograph (MOS) of the Canada-France-Hawaii Telescope (CFHT), an investigation that has added 96 new velocities to and confirmed many of the earlier values in a preexisting data set of 256 velocities published elsewhere. The photometry, consisting of magnitudes and colors in the Washington (T_1_, C-T_1_) system, is based on CCD observations made at the Cerro Tololo Inter-American Observatory (CTIO) and the Kitt Peak National Observatory (KPNO).
1006. Globulars of M81
ID:
ivo://CDS.VizieR/J/AJ/109/1055
Title:
Globulars of M81
Short Name:
J/AJ/109/1055
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have obtained photometric BVR, morphological, and astrometric information on 3774 objects located within a 25' radius of M81. This catalogue is complete for 15 <= V <= 21; it is used here to identify globular cluster candidates in M81 and as a database for a statistical analysis of the system as a whole. The M81 globular cluster system is revealed as a strong surface density excess of ~70 objects within an 11 kpc galactocentric radius. The total population is estimated at N_T = 210 +/- 30 globulars. The spatial, (B-V), and (V-R) distributions are very similar to those of the Milky Way and of M31. Small but significant systematic errors in Madore et al.'s [AJ, 106, 2243 (1993)] photometry could be responsible for an overestimate of the Cepheid distance to M81 [(m-M)0 = 27.8] and we propose a revised modulus of (m-M)0 = 27.5 +/- 0.3. The globular cluster luminosity function then reaches its maximum at M_V* = -7.5 +/- 0.4, as it does in the galaxy and in M31. There is suggestive evidence that 13 +/- 5 objects are globulars seen through the disk of M81; spectroscopy or high-resolution imaging will resolve this issue. Using the (B-R)0 index to trace [Fe/H], we notice a weak dependence of mean metallicity on galactocentric distance, as observed in the galaxy and in M31. This result argues in favour of in situ globular formation during the continuous collapse and self-enrichment of an early-type spiral host.
1007. GMBCG galaxy cluster catalog from SDSS DR7
ID:
ivo://CDS.VizieR/J/ApJS/191/254
Title:
GMBCG galaxy cluster catalog from SDSS DR7
Short Name:
J/ApJS/191/254
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a large catalog of optically selected galaxy clusters from the application of a new Gaussian Mixture Brightest Cluster Galaxy (GMBCG) algorithm to SDSS Data Release 7 data. The algorithm detects clusters by identifying the red-sequence plus brightest cluster galaxy (BCG) feature, which is unique for galaxy clusters and does not exist among field galaxies. Red-sequence clustering in color space is detected using an Error Corrected Gaussian Mixture Model. We run GMBCG on 8240 deg^2^ of photometric data from SDSS DR7 to assemble the largest ever optical galaxy cluster catalog, consisting of over 55,000 rich clusters across the redshift range from 0.1<z<0.55. We present Monte Carlo tests of completeness and purity and perform cross-matching with X-ray clusters and with the maxBCG sample at low redshift. These tests indicate high completeness and purity across the full redshift range for clusters with 15 or more members.
1008. GMOS/WIYN spectroscopic catalogue
ID:
ivo://CDS.VizieR/J/MNRAS/405/2243
Title:
GMOS/WIYN spectroscopic catalogue
Short Name:
J/MNRAS/405/2243
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the largest spectroscopic follow-up performed in SWIRE ELAIS-N1. We were able to determine redshifts for 289 extragalactic sources. The values of spectroscopic redshifts of the latter have been compared with the estimated values from our photometric redshift code with very good agreement between the two for both galaxies and quasars.
1009. GOBELINS. IV. VLBA obs. of Taurus
ID:
ivo://CDS.VizieR/J/ApJ/859/33
Title:
GOBELINS. IV. VLBA obs. of Taurus
Short Name:
J/ApJ/859/33
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new trigonometric parallaxes and proper motions of young stellar objects in the Taurus molecular cloud complex from observations collected with the Very Long Baseline Array as part of the Gould's Belt Distances Survey. We detected 26 young stellar objects and derived trigonometric parallaxes for 18 stars with an accuracy of 0.3% to a few percent. We modeled the orbits of six binaries and determined the dynamical masses of the individual components in four of these systems (V1023 Tau, T Tau S, V807 Tau, and V1000 Tau). Our results are consistent with the first trigonometric parallaxes delivered by the Gaia satellite and reveal the existence of significant depth effects. We find that the central portion of the dark cloud Lynds 1495 is located at d=129.5+/-0.3pc, while the B216 clump in the filamentary structure connected to it is at d=158.1+/-1.2pc. The closest and remotest stars in our sample are located at d=126.6+/-1.7pc and d=162.7+/-0.8pc, yielding a distance difference of about 36pc. We also provide a new distance estimate for HL Tau that was recently imaged. Finally, we compute the spatial velocity of the stars with published radial velocity and investigate the kinematic properties of the various clouds and gas structures in this region.
1010. GOBELINS. V. Kinematics of Perseus
ID:
ivo://CDS.VizieR/J/ApJ/865/73
Title:
GOBELINS. V. Kinematics of Perseus
Short Name:
J/ApJ/865/73
Date:
21 Oct 2021
Publisher:
CDS
Description:
We derive the distance and structure of the Perseus molecular cloud by combining trigonometric parallaxes from Very Long Baseline Array (VLBA) observations, taken as part of the GOBELINS survey and Gaia Data Release 2. Based on our VLBA astrometry, we obtain a distance of 321+/-10pc for IC 348. This is fully consistent with the mean distance of 320+/-26 measured by Gaia. The VLBA observations toward NGC 1333 are insufficient to claim a successful distance measurement to this cluster. Gaia parallaxes, on the other hand, yield a mean distance of 293+/-22pc. Hence, the distance along the line of sight between the eastern and western edges of the cloud is ~30pc, which is significantly smaller than previously inferred. We use Gaia proper motions and published radial velocities to derive the spatial velocities of a selected sample of stars. The average velocity vectors with respect to the LSR are (u,v,w)=(-6.1+/-1.6, 6.8+/-1.1, -0.9+/-1.2) and (-6.4+/-1.0, 2.1+/-1.4, -2.4+/-1.0)km/s for IC 348 and NGC 1333, respectively. Finally, our analysis of the kinematics of the stars has shown that there is no clear evidence of expansion, contraction, or rotational motions within the clusters.