scholarly journals Catalogue of variable stars in Milky Way globular clusters

2017 ◽  
Vol 152 ◽  
pp. 01021 ◽  
Author(s):  
Christine Clement
2009 ◽  
Vol 5 (S262) ◽  
pp. 287-290
Author(s):  
M. Hempel ◽  
D. Minniti ◽  
R. Saito ◽  
P. Pietrukowicz ◽  
P. W. Lucas

AbstractOver the next 5 years the VVV collaboration (Vista Variable in the Via Lactea) will conduct an extensive survey of the galactic bulge and disk in the near-IR, using the new VISTA telescope. This public survey covers a field of 520 sqr. deg, including not only regions of high star formation, but also 33 known globular clusters and ~350 open clusters. The final product will be a deep IR atlas in 5 passbands for ~109 point sources among which we expect 106 variable stars. These will be produce a 3-D map of the surveyed region using well-understood primary distance indicators such as RR Lyrae stars. The observations will be combined with data from MACHO, OGLE, EROS, VST, Spitzer, HST, Chandra, Integral, and ALMA for a complete understanding of the variable sources in the inner Milky Way. Several important implications for the history of the Milky Way, for globular cluster evolution, for the population census of the bulge and center, and for the pulsation theory will follow from this survey.


2020 ◽  
Vol 500 (2) ◽  
pp. 2514-2524
Author(s):  
Joel Pfeffer ◽  
Carmela Lardo ◽  
Nate Bastian ◽  
Sara Saracino ◽  
Sebastian Kamann

ABSTRACT A number of the massive clusters in the halo, bulge, and disc of the Galaxy are not genuine globular clusters (GCs) but instead are different beasts altogether. They are the remnant nuclear star clusters (NSCs) of ancient galaxies since accreted by the Milky Way. While some clusters are readily identifiable as NSCs and can be readily traced back to their host galaxy (e.g. M54 and the Sagittarius Dwarf galaxy), others have proven more elusive. Here, we combine a number of independent constraints, focusing on their internal abundances and overall kinematics, to find NSCs accreted by the Galaxy and trace them to their accretion event. We find that the true NSCs accreted by the Galaxy are: M54 from the Sagittarius Dwarf, ω Centari from Gaia-Enceladus/Sausage, NGC 6273 from Kraken, and (potentially) NGC 6934 from the Helmi Streams. These NSCs are prime candidates for searches of intermediate-mass black holes (BHs) within star clusters, given the common occurrence of galaxies hosting both NSCs and central massive BHs. No NSC appears to be associated with Sequoia or other minor accretion events. Other claimed NSCs are shown not to be such. We also discuss the peculiar case of Terzan 5, which may represent a unique case of a cluster–cluster merger.


1975 ◽  
Vol 67 ◽  
pp. 541-543
Author(s):  
A. V. Mironov ◽  
N. N. Samus'

The dependences of the numbers of variable stars in globular clusters on the chemical composition are studied. For given metallicity the numbers of RR Lyrae stars reduced to some definite total number of stars in the cluster are different for the two groups of globular clusters introduced by Mironov.


2016 ◽  
Vol 11 (S321) ◽  
pp. 10-12
Author(s):  
Charli M. Sakari

AbstractObservations of stellar streams in M31’s outer halo suggest that M31 is actively accreting several dwarf galaxies and their globular clusters (GCs). Detailed abundances can chemically link clusters to their birth environments, establishing whether or not a GC has been accreted from a satellite dwarf galaxy. This talk presents the detailed chemical abundances of seven M31 outer halo GCs (with projected distances from M31 greater than 30 kpc), as derived from high-resolution integrated-light spectra taken with the Hobby Eberly Telescope. Five of these clusters were recently discovered in the Pan-Andromeda Archaeological Survey (PAndAS)—this talk presents the first determinations of integrated Fe, Na, Mg, Ca, Ti, Ni, Ba, and Eu abundances for these clusters. Four of the target clusters (PA06, PA53, PA54, and PA56) are metal-poor ([Fe/H] < -1.5), α-enhanced (though they are possibly less alpha-enhanced than Milky Way stars at the 1 sigma level), and show signs of star-to-star Na and Mg variations. The other three GCs (H10, H23, and PA17) are more metal-rich, with metallicities ranging from [Fe/H] = -1.4 to -0.9. While H23 is chemically similar to Milky Way field stars, Milky Way GCs, and other M31 clusters, H10 and PA17 have moderately-low [Ca/Fe], compared to Milky Way field stars and clusters. Additionally, PA17’s high [Mg/Ca] and [Ba/Eu] ratios are distinct from Milky Way stars, and are in better agreement with the stars and clusters in the Large Magellanic Cloud (LMC). None of the clusters studied here can be conclusively linked to any of the identified streams from PAndAS; however, based on their locations, kinematics, metallicities, and detailed abundances, the most metal-rich PAndAS clusters H23 and PA17 may be associated with the progenitor of the Giant Stellar Stream, H10 may be associated with the SW Cloud, and PA53 and PA56 may be associated with the Eastern Cloud.


2017 ◽  
Vol 152 ◽  
pp. 01022
Author(s):  
Javier Alonso-García ◽  
Márcio Catelan ◽  
Rodrigo Contreras Ramos ◽  
István Dékány ◽  
Dante Minniti

2016 ◽  
Vol 462 (2) ◽  
pp. 1937-1951 ◽  
Author(s):  
A. Sollima ◽  
F. R. Ferraro ◽  
L. Lovisi ◽  
F. Contenta ◽  
E. Vesperini ◽  
...  

REPORTS ◽  
2021 ◽  
Vol 6 (340) ◽  
pp. 94-105
Author(s):  
M.V. Ishchenko ◽  
M.O. Sobolenko ◽  
M.T. Kalambay ◽  
B.T. Shukirgaliyev ◽  
P.P. Berczik

2022 ◽  
Vol 258 (1) ◽  
pp. 20
Author(s):  
Iminhaji Ablimit ◽  
Gang Zhao ◽  
Uy. Teklimakan ◽  
Jian-Rong Shi ◽  
Kunduz Abdusalam

Abstract In order to study the Milky Way, RR Lyrae (RRL) variable stars identified by Gaia, ASAS-SN, and ZTF sky survey projects have been analyzed as tracers in this work. Photometric and spectroscopic information of 3417 RRLs including proper motions, radial velocity, and metallcity are obtained from observational data of Gaia, LAMOST, GALAH, APOGEE, and RAVE. Precise distances of RRLs with typical uncertainties less than 3% are derived by using a recent comprehensive period–luminosity–metallicity relation. Our results from kinematical and chemical analysis provide important clues for the assembly history of the Milky Way, especially for the Gaia–Sausage ancient merger. The kinematical and chemical trends found in this work are consistent with those of recent simulations that indicated that the Gaia–Sausage merger had a dual origin in the Galactic thick disk and halo. As recent similar works have found, the halo RRL sample in this work contains a subset of radially biased orbits besides a more isotropic component. This higher orbital anisotropy component amounts to β ≃ 0.8, and it contributes between 42% and 83% of the halo RRLs at 4 < R( kpc) < 20.


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