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Related papers: The HST large programme on $\omega$ Centauri - II.…

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In this work, we characterize the properties of HB stars in the GCs $\omega$ Cen and NGC 6752. We use dedicated model atmospheres and synthetic spectra grids computed using a hybrid LTE/NLTE modeling approach to fit the MUSE spectra of HB…

Solar and Stellar Astrophysics · Physics 2023-09-13 M. Latour , S. Hämmerich , M. Dorsch , U. Heber , T. -O. Husser , S. Kamann , S. Dreizler , J. Brinchmann

The formation process of multiple populations in globular clusters is still up for debate. Kinematic differences between the populations are particularly interesting in this respect, because they allow us to distinguish between single-epoch…

We use the SDSS-Gaia catalogue to search for substructure in the stellar halo. The sample comprises 62\,133 halo stars with full phase space coordinates and extends out to heliocentric distances of $\sim 10$ kpc. As actions are conserved…

Astrophysics of Galaxies · Physics 2018-07-03 G. C. Myeong , N. W. Evans , V. Belokurov , J. L. Sanders , S. E. Koposov

The stellar dynamics of Omega Centauri are inferred from the radial velocities of 469 stars measured with CORAVEL (Mayor et al. 1997). Rather than fit the data to a family of models, we generate estimates of all dynamical functions…

Astrophysics · Physics 2009-10-28 David Merritt , G. Meylan , M. Mayor

The central regions of the globular cluster Omega Centauri ($\omega$ Cen) have been extensively studied, but its outer regions and tidal structure have been less so. Gaia's astrometry uncovered substantial tidal substructure associated with…

Astrophysics of Galaxies · Physics 2025-02-04 P. B. Kuzma , M. N. Ishigaki

Observations of internal motions in globular clusters offer unique insights into the dynamics of the clusters. We have recently developed methods of high-precision astrometry with HST's WFPC2 camera, which allow us to measure internal…

Astrophysics · Physics 2007-05-23 Ivan R. King , Jay Anderson

In this paper we report a new estimate of the absolute proper motion (PM) of the globular cluster NGC 5139 ($\omega$ Cen) as part of the HST large program GO-14118+14662. We analyzed a field 17 arcmin South-West of the center of $\omega$…

Proper motions (PMs) are crucial to fully understand the internal dynamics of globular clusters (GCs). To that end, the Hubble Space Telescope (HST) Proper Motion (HSTPROMO) collaboration has constructed large, high-quality PM catalogues…

Astrophysics of Galaxies · Physics 2017-01-31 Laura L. Watkins , Roeland P. van der Marel , Andrea Bellini , A. T. Baldwin , P. Bianchini , J. Anderson

We have carried out a set of Monte Carlo simulations to study a number of fundamental aspects of the dynamical evolution of multiple stellar populations in globular clusters with different initial masses, fractions of second generation (2G)…

Astrophysics of Galaxies · Physics 2021-03-03 E. Vesperini , J. Hong , M. Giersz , A. Hypki

We present an extensive photometry on HB, RGB, and MSTO stars in Omega Cen. The central regions of the cluster were covered with a mosaic of F435W, F625W, and F658N-band data collected with ACS/HST. The outer reaches were covered with a…

The presence of extreme horizontal branch (EHB) and blue hook stars in some Galactic globular clusters (GGCs) constitutes one of the remaining mysteries of stellar evolution. In this paper, we focus on $\omega$ Cen, a peculiar, massive GGC…

Solar and Stellar Astrophysics · Physics 2018-10-10 Marilyn Latour , Suzanna K. Randall , Annalisa Calamida , Stephan Geier , Sabine Moehler

We present the analysis of the radial distributions and kinematic properties of the multiple stellar populations (mPOPs) hosted in the globular cluster (GC) NGC 6352 as part of the Hubble Space Telescope (HST) "UV Legacy Survey of Galactic…

Solar and Stellar Astrophysics · Physics 2019-03-20 M. Libralato , A. Bellini , G. Piotto , D. Nardiello , R. P. van der Marel , J. Anderson , L. R. Bedin , E. Vesperini

We report proper motion dispersions for stars in the direction of two fields of the Galactic bulge, using HST/WFPC2 images taken six years apart. Our two fields are Baade's Window (l,b)=(1.13,-3.77) and Sgr I (l,b)=(1.25 ,-2.65). Our proper…

Astrophysics · Physics 2016-08-30 Konrad Kuijken , R. Michael Rich

We constructed a Hubble Space Telescope (HST) astro-photometric catalog of the central region of the Galactic globular cluster NGC 1261. This catalog, complemented with Gaia DR2 data sampling the external regions, has been used to estimate…

Solar and Stellar Astrophysics · Physics 2020-05-27 S. Raso , M. Libralato , A. Bellini , F. R. Ferraro , B. Lanzoni , M. Cadelano , C. Pallanca , E. Dalessandro , G. Piotto , J. Anderson , S. T. Sohn

We take advantage of the exquisite quality of the Hubble Space Telescope 26-filter astro-photometric catalog of the core of Omega Cen presented in the first paper of this series and the empirical differential-reddening correction presented…

Solar and Stellar Astrophysics · Physics 2017-08-09 A. Bellini , A. P. Milone , J. Anderson , A. F. Marino , G. Piotto , R. P. van der Marel , L. R. Bedin , I. R. King

We have used the ARGUS multi-object spectrometer at the CTIO 4m Blanco telescope to obtain 2756 radial velocity measurements for 1966 individual stars in the globular cluster omega Centauri brighter than blue photographic magnitude of about…

The galactic globular cluster Omega Centauri is the most massive of its kind, with a complex mix of multiple stellar populations and several kinematic and dynamical peculiarities. Different mean proper motions have been detected among the…

Solar and Stellar Astrophysics · Physics 2020-05-13 N. Sanna , E. Pancino , A. Zocchi , F. R. Ferraro , P. B. Stetson

We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of 30 Galactic Globular Clusters to characterize two distinct stellar populations. A sophisticated Bayesian technique is employed to…

Solar and Stellar Astrophysics · Physics 2016-09-21 R. Wagner-Kaiser , D. C. Stenning , A. Sarajedini , T. von Hippel , D. A. van Dyk , E. Robinson , N. Stein , W. H. Jefferys

We present the first 3D kinematic analysis of multiple stellar populations (MPs) in a representative sample of 16 Galactic globular clusters (GCs). For each GC in the sample we studied the MP line-of-sight, plane-of-the-sky and 3D rotation…

An understanding of the assembly history of the complex star cluster Omega Centauri has long been sought after, with many studies separating the stars on the color-magnitude diagram into multiple groupings across small magnitude ranges.…