- ID:
- ivo://CDS.VizieR/J/MNRAS/458/4162
- Title:
- Stromgren photometry of M3 (NGC5272)
- Short Name:
- J/MNRAS/458/4162
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Stroemgren photometry of the Galactic Globular Cluster M3 to study its multiple generations phenomenon. The use of different colour-magnitude diagrams (CMDs) and especially of the notoriously efficient c_y_ index allowed us to detect a double red giant branch in the cluster CMD. After decontamination from fore- and background sources, the two sequences turned out to be equally populated. The two components also show a bimodal radial distribution well corresponding to that predicted by numerical simulations for clusters living in an intermediate dynamical evolutive state and with a population with modified chemical composition that was born more centrally concentrated than the primordial. The analysis of high-resolution spectra quantitatively demonstrates that the two detected sequences correspond to the first (Na-poor) generation and the second (Na-rich) generation, thus confirming the importance of synergy between photometry and spectroscopy.
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- ID:
- ivo://CDS.VizieR/J/AJ/120/3111
- Title:
- Stromgren photometry of NGC 6397
- Short Name:
- J/AJ/120/3111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry extending below the turnoff of the globular cluster NGC 6397 on the uvbyH{beta} system is presented and analyzed. Restricting the sample to stars with small photometric errors and highly probable cluster membership, the reddening from approximately 1500 stars at the turnoff is E(b-y)=0.127+/-0.002 (standard error of the mean), equivalent to E(B-V)=0.179+/-0.003. The photometric abundance for the same sample, on the revised spectroscopic scale for globular clusters, is [Fe/H]=-1.82+/-0.04 (standard error of the mean). From 220 cluster red giants, well-defined relations are established for m_1_ and c_1_ as a function of b-y.
- ID:
- ivo://CDS.VizieR/J/AJ/146/20
- Title:
- Structural parameters for 79 globular clusters in M31
- Short Name:
- J/AJ/146/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present surface brightness profiles for 79 globular clusters in M31, using images observed with the Hubble Space Telescope, some of which are from new observations. The structural and dynamical parameters are derived from fitting the profiles to several different models for the first time. The results show that in the majority of cases, King models fit the M31 clusters just as well as Wilson models and better than S\'ersic models. However, there are 11 clusters best fitted by Sersic models with the Sersic index n>2, meaning that they have cuspy central density profiles. These clusters may be the well-known core-collapsed candidates. There is a bimodality in the size distribution of M31 clusters at large radii, which is different from their Galactic counterparts. In general, the properties of clusters in M31 and the Milky Way fall in the same regions of parameter spaces. The tight correlations of cluster properties indicate a "fundamental plane" for clusters, which reflects some universal physical conditions and processes operating at the epoch of cluster formation.
- ID:
- ivo://CDS.VizieR/J/AJ/131/414
- Title:
- Structural parameters of SMC star clusters
- Short Name:
- J/AJ/131/414
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present structural parameters for 204 stellar clusters in the Small Magellanic Cloud derived from fitting King and Elson, Fall, and Freeman (EFF, 1987ApJ...323...54E) model profiles to the V-band surface brightness profiles as measured from the Magellanic Clouds Photometric Survey images.
- ID:
- ivo://CDS.VizieR/VII/151
- Title:
- Structure Parameters of Galactic Globular Clusters
- Short Name:
- VII/151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains observed and derived structure parameters for 154 galactic globular clusters, 7 dwarf spheroidal satellites of the Galaxy, and 6 globular clusters in the Fornax dwarf spheroids, respectively, in six different files. Files 1-3 (table1a, table1b, & table1c) list observed parameters, including cluster designation in order of right ascension, equatorial coordinates (B1950), apparent level of the cluster horizontal branch, reddening, subgiant branch color, limiting and core angular radii, ellipticities (only for table1b), integrated magnitude and central surface brightness. Files 4-6 (table2a, table2b, & table2c) contain positional and structural data derived from the observational data of table1. These include, for instance, galactic and galactocentric or Cartesian coordinates, heliocentric and galactocentric distances, or angular and projected linear distances, position angle, metallicity, limiting and core radii, central relaxation time scale, central mass density, central velocity dispersion, and central escape velocity. The references (all columns which label start by r_) are not available in electronic form.
- ID:
- ivo://CDS.VizieR/J/MNRAS/414/3699
- Title:
- Study of hot stellar systems and galaxies
- Short Name:
- J/MNRAS/414/3699
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a complete picture of dynamically hot stellar systems, ranging from faint galaxies and star clusters of only a few hundred solar masses up to giant elliptical galaxies, in particular including large samples of compact elliptical galaxies (cEs), ultra-compact dwarf galaxies (UCDs), dwarf elliptical galaxies (dEs) of nearby galaxy clusters, and Local Group ultra-faint dwarf spheroidal galaxies (dSphs). For all those stellar systems we show the effective radius-luminosity, effective radius-stellar mass, and effective mass surface density-stellar mass plane.
- ID:
- ivo://CDS.VizieR/J/AJ/132/447
- Title:
- Surface Brightness of 38 Gal. Globular Clusters
- Short Name:
- J/AJ/132/447
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hubble Space Telescope (HST) allows us to study the central surface brightness profiles of globular clusters at unprecedented detail. We have mined the HST archives to obtain 38 WFPC2 images of Galactic globular clusters with adequate exposure times and filters, which we use to measure their central structure.
- ID:
- ivo://CDS.VizieR/J/AJ/143/132
- Title:
- Surface brightness profiles of 10 globulars of M31
- Short Name:
- J/AJ/143/132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present internal surface brightness profiles, using images in the F606W and F814W filter bands observed with the Advanced Camera for Surveys on the Hubble Space Telescope, for 10 globular clusters (GCs) in the outer halo of M31. Standard King models are fitted to the profiles to derive their structural and dynamical parameters. The results show that, in general, the properties of clusters in M31 and the Milky Way fall in the same regions of parameter spaces. The outer halo GCs of M31 have larger ellipticities than most of the GCs in M31 and the Milky Way. Their large ellipticities may be due to galaxy tides coming from satellite dwarf galaxies of M31 or may be related to the apparently more vigorous accretion or merger history that M31 has experienced. The tight correlation of cluster binding energy E_b_ with mass M_mod_indicates that the "fundamental plane" does exist for clusters, regardless of their host environments, which is consistent with previous studies.
- ID:
- ivo://CDS.VizieR/J/AJ/149/157
- Title:
- Surface intensity profiles for 10 M33 globular clusters
- Short Name:
- J/AJ/149/157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present the properties of 10 halo globular clusters (GCs) with luminosities L~=5-7x10^5^L_{sun}_ in the Local Group galaxy M33 using images from the Hubble Space Telescope WFPC2 in the F555W and F814W bands. We obtained the ellipticities, position angles, and surface brightness profiles for each GC. In general, the ellipticities of the M33 sample clusters are similar to those of the M31 clusters. The structural and dynamical parameters are derived by fitting the profiles to three different models combined with mass-to-light ratios (M/L values) from population-synthesis models. The structural parameters include core radii, concentration, half-light radii, and central surface brightness. The dynamical parameters include the integrated cluster mass, integrated binding energy, central surface mass density, and predicted line of sight velocity dispersion at the cluster center. The velocity dispersions of the four clusters predicted here agree well with the observed dispersions by Larsen et al. The results here showed that the majority of the sample halo GCs are better fitted by both the King model and the Wilson model than the Sersic model. In general, the properties of the clusters in M33, M31, and the Milky Way fall in the same regions of parameter spaces. The tight correlations of cluster properties indicate a "fundamental plane" for clusters, which reflects some universal physical conditions and processes operating at the epoch of cluster formation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/3444
- Title:
- Survey of Centaurus A's Baryonic Structures II.
- Short Name:
- J/MNRAS/469/3444
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New wide-field u'g'r'i'z' Dark Energy Camera observations centred on the nearby giant elliptical galaxy NGC 5128 covering ~21 deg^2^ are used to compile a new catalogue of ~3200 globular clusters (GCs). We report 2404 newly identified candidates, including the vast majority within ~140kpc of NGC 5128. We find evidence for a transition at a galactocentric radius of R_gc_~=55kpc from GCs 'intrinsic' to NGC 5128 to those likely to have been accreted from dwarf galaxies or that may transition to the intragroup medium of the Centaurus A galaxy group. We fit power-law surface number density profiles of the form {Sigma}_N,R_gc_{prop.to}R_gc_^{Gamma}^ and find that inside the transition radius, the red GCs are more centrally concentrated than the blue, with {Gamma}_inner,red_~=-1.78 and {Gamma}_inner,blue_~=-1.40, respectively. Outside this region both profiles flatten, more dramatically for the red GCs ({Gamma}_outer,red_~=-0.33) compared to the blue ({Gamma}_outer,blue_~= -0.61), although the former is more likely to suffer contamination by background sources. The median (g'-z')_0_=1.27mag colour of the inner red population is consistent with arising from the amalgamation of two giant galaxies each less luminous than present-day NGC 5128. Both inwards and outwards of the transition radius, we find the fraction of blue GCs to dominate over the red GCs, indicating a lively history of minor mergers. Assuming the blue GCs to originate primarily in dwarf galaxies, we model the population required to explain them, while remaining consistent with NGC 5128's present-day spheroid luminosity. We find that several dozen dwarfs of luminosities L_dw,V_~= 10^6-9.3^L_V,{sun}_, following a Schechter luminosity function with a faint-end slope of -1.50<={alpha}<=-1.25 is favoured, many of which may have already been disrupted in NGC 5128's tidal field.
