Star Density Distribution in Young and Old Globular Clusters of the Large Magellanic Cloud

Star Clusters ◽  
1980 ◽  
pp. 341-341
Author(s):  
E. H. Geyer ◽  
U. Hopp ◽  
M. Kiehl ◽  
S. Witzigmann
Keyword(s):  
Density Distribution ◽  
Globular Clusters ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Star Density

scholarly journals Star Density Distribution in Young and Old Globular Clusters of the Large Magellanic Cloud

1980 ◽  
Vol 85 ◽  
pp. 341-341
Author(s):  
E. H. Geyer ◽  
U. Hopp ◽  
M. Kiehl ◽  
S. Witzigmann
Keyword(s):  
Density Distribution ◽  
Globular Clusters ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Schmidt Telescope ◽  
Star Density ◽  
Absolute Magnitudes

The star density distribution in NGC 1818, 2004, 1806 and 1846, which are representative for the “blue” and “red” globular clusters of the LMC, have been determined from star counts on B- and V- ESO Schmidt telescope plates. These have limiting magnitudes of about 21, thus stars with absolute magnitudes of about Mv ~ +2 are reached. It was found that the two cluster types can be treated as “polytropic stargas spheres” according to the Schuster law with an index n ~ 2.75.

scholarly journals VARIABLE STARS IN LARGE MAGELLANIC CLOUD GLOBULAR CLUSTERS. I. NGC 1466

2011 ◽  
Vol 142 (4) ◽  
pp. 107 ◽  
Author(s):  
Charles A. Kuehn ◽  
Horace A. Smith ◽  
Márcio Catelan ◽  
Barton J. Pritzl ◽  
Nathan De Lee ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Large Magellanic Cloud ◽  
Variable Stars ◽  
Magellanic Cloud

scholarly journals IntegratedK-band spectra of old and intermediate-age globular clusters in the Large Magellanic Cloud

2010 ◽  
Vol 510 ◽  
pp. A19 ◽  
Author(s):  
M. Lyubenova ◽  
H. Kuntschner ◽  
M. Rejkuba ◽  
D. R. Silva ◽  
M. Kissler-Patig ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Band Spectra

scholarly journals Gaia Data Release 2

2018 ◽  
Vol 616 ◽  
pp. A12 ◽  
Author(s):  
◽  
A. Helmi ◽  
F. van Leeuwen ◽  
P. J. McMillan ◽  
D. Massari ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Milky Way ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Proper Motions ◽  
Single Plane ◽  
Dwarf Spheroidal Galaxies ◽  
Orbital Parameters ◽  
Data Release ◽  
Using Data

Context. Aims. The goal of this paper is to demonstrate the outstanding quality of the second data release of the Gaia mission and its power for constraining many different aspects of the dynamics of the satellites of the Milky Way. We focus here on determining the proper motions of 75 Galactic globular clusters, nine dwarf spheroidal galaxies, one ultra-faint system, and the Large and Small Magellanic Clouds. Methods. Using data extracted from the Gaia archive, we derived the proper motions and parallaxes for these systems, as well as their uncertainties. We demonstrate that the errors, statistical and systematic, are relatively well understood. We integrated the orbits of these objects in three different Galactic potentials, and characterised their properties. We present the derived proper motions, space velocities, and characteristic orbital parameters in various tables to facilitate their use by the astronomical community. Results. Our limited and straightforward analyses have allowed us for example to (i) determine absolute and very precise proper motions for globular clusters; (ii) detect clear rotation signatures in the proper motions of at least five globular clusters; (iii) show that the satellites of the Milky Way are all on high-inclination orbits, but that they do not share a single plane of motion; (iv) derive a lower limit for the mass of the Milky Way of 9.1-2.6+6.2 × 1011 M⊙ based on the assumption that the Leo I dwarf spheroidal is bound; (v) derive a rotation curve for the Large Magellanic Cloud based solely on proper motions that is competitive with line-of-sight velocity curves, now using many orders of magnitude more sources; and (vi) unveil the dynamical effect of the bar on the motions of stars in the Large Magellanic Cloud. Conclusions. All these results highlight the incredible power of the Gaia astrometric mission, and in particular of its second data release.

scholarly journals Exploring the nature and synchronicity of early cluster formation in the Large Magellanic Cloud – IV. Evidence for multiple populations in Hodge 11 and NGC 2210

2019 ◽  
Vol 486 (4) ◽  
pp. 5581-5599 ◽  
Author(s):  
Christina K Gilligan ◽  
Brian Chaboyer ◽  
Jeffrey D Cummings ◽  
Dougal Mackey ◽  
Roger E Cohen ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Main Sequence ◽  
Hubble Space Telescope ◽  
Cluster Formation ◽  
Stellar Populations ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Wide Field ◽  
Horizontal Branch ◽  
Advanced Camera For Surveys

Abstract We present a multiple population search in two old Large Magellanic Cloud (LMC) Globular clusters, Hodge 11 and NGC 2210. This work uses data from the Advanced Camera for Surveys and Wide Field Camera 3 on the Hubble Space Telescope from programme GO-14164 in Cycle 23. Both of these clusters exhibit a broadened main sequence with the second population representing (20 ± ∼5) per cent for NGC 2210 and (30 ± ∼5) per cent for Hodge 11. In both clusters, the smaller population is redder than the primary population, suggesting CNO variations. Hodge 11 also displays a bluer second population in the horizontal branch, which is evidence for helium enhancement. However, even though NGC 2210 shows similarities to Hodge 11 in the main sequence, there does not appear to be a second population on NGC 2210’s horizontal branch. This is the first photometric evidence that ancient LMC Globular clusters exhibit multiple stellar populations.

scholarly journals An Ellipticity-Age Relation for Globular Clusters in the Large Magellanic Cloud

1984 ◽  
Vol 108 ◽  
pp. 27-28
Author(s):  
S. Michael Fall ◽  
Carlos S. Frenk
Keyword(s):  
Globular Clusters ◽  
Reasonable Agreement ◽  
Large Magellanic Cloud ◽  
Systematic Difference ◽  
Magellanic Cloud ◽  
Three Dimensions ◽  
Sky Surveys ◽  
The Galaxy ◽  
Age Relation ◽  
Cluster A

We have measured the ellipticities of 52 globular clusters in the LMC and 93 in the Galaxy by eye from polaroid enlargements of the sky surveys (Frenk & Fall 1982). In most cases, the measurements pertain to regions between (1–2)rh where rh is the median radius of a cluster; i.e. the radius containing half of the light in three dimensions. These were compared with determinations based on star counts for 12 members of the LMC sample and 19 members of the Galactic sample. We found no systematic difference between the ellipticities from the two methods and concluded that the eye-measurements are free of any major bias. They are also in reasonable agreement with the measurements by Geyer & Richtler (1981) and Geyer, Hopp & Nelles (1983), who used the Agfa contourfilm technique. The ellipticities measured by Geisler & Hodge (1980) from microdensitometer scans are systematically large in comparison with our results and those of Geyer and his associates. Since the scans cover only a small part of each cluster, a few bright stars can cause spurious elongations in the fitted contours.

scholarly journals Chromosome maps of young LMC clusters: an additional case of coeval multiple populations

2020 ◽  
Vol 493 (4) ◽  
pp. 6060-6070 ◽  
Author(s):  
S Saracino ◽  
S Martocchia ◽  
N Bastian ◽  
V Kozhurina-Platais ◽  
W Chantereau ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Hubble Space Telescope ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Host Galaxy ◽  
Clear Correlation ◽  
Age Difference ◽  
Multiple Star ◽  
Multiple Populations ◽  
Red Giant

ABSTRACT Recent studies have revealed that the multiple populations (MPs) phenomenon does not occur only in ancient and massive Galactic globular clusters (GCs), but it is also observed in external galaxies, where GCs sample a wide age range with respect to the Milky Way. However, for a long time, it was unclear whether we were looking at the same phenomenon in different environments or not. The first evidence that the MPs phenomenon is the same regardless of cluster age and host galaxy came out recently, when an intermediate-age cluster from the Small Magellanic Cloud, Lindsay 1, and a Galactic GC have been directly compared. By complementing those data with new images from the Hubble Space Telescope (HST), we extend the comparison to two clusters of different ages: NGC 2121 (∼2.5 Gyr) and NGC 1783 (∼1.5 Gyr), from the Large Magellanic Cloud. We find a clear correlation between the RGB (red giant branch) width in the pseudo-colour CF275W, F343N, F438W and the age of the cluster itself, with the older cluster having larger σ(CF275W, F343N, F438W)RGB and vice versa. Unfortunately, the σ values cannot be directly linked to the N-abundance variations within the clusters before properly taking account the effect of the first dredge-up. Such HST data also allow us to explore whether multiple star formation episodes occurred within NGC 2121. The two populations are indistinguishable, with an age difference of only 6 ± 12 Myr and an initial helium spread of 0.02 or lower. This confirms our previous results, putting serious constraints on any model proposed to explain the origin of the chemical anomalies in GCs.

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