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Related papers: Deep ACS Imaging in the Globular Cluster NGC6397: …

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We examine the theoretical implications of a population of low-mass helium-core white dwarfs in globular clusters. In particular, we focus on the observed population in the core of NGC 6397, where several low-mass white dwarf canditates…

Astrophysics · Physics 2009-11-07 Brad Hansen , Vassiliki Kalogera , Frederic A. Rasio

Recently, \citet{vitral2021does} detected a central concentration of dark objects in the core-collapsed globular cluster NGC 6397, which could be interpreted as a subcluster of stellar-mass black holes. However, it is well established…

We report our study of features at the observed red end of the white dwarf cooling sequences for three Galactic globular clusters: NGC\,6397, 47\,Tucanae and M\,4. We use deep colour-magnitude diagrams constructed from archival Hubble Space…

We present results of a study of the central regions of NGC 6397 using Hubble Space Telescope's Advanced Camera for Surveys, focusing on a group of 24 faint blue stars that form a sequence parallel to, but brighter than, the more populated…

Astrophysics of Galaxies · Physics 2011-02-11 R. R. Strickler , A. M. Cool , J. Anderson , H. N. Cohn , P. M. Lugger , A. M. Serenelli

We present photometry for the globular cluster NGC 6642 using the F606W and F814W filters with the ACS/WFC third generation camera on board of Hubble Space Telescope. The Colour Magnitude Diagram shows sources reaching ~ 6 mags below the…

Astrophysics of Galaxies · Physics 2015-05-13 E. Balbinot , B. X. Santiago , E. Bica , C. Bonatto

We have investigated the properties of the stellar mass function in the globular cluster NGC6397 using a large set of HST observations that include WFPC2 images in V and I, obtained at ~4' and 10' radial distances, and a series of deep…

Astrophysics · Physics 2009-10-31 Guido De Marchi , Francesco Paresce , Luigi Pulone

The evolution of star clusters is studied using N-body simulations in which the evolution of single stars and binaries are taken self-consistently into account. Initial conditions are chosen to represent relatively young Galactic open…

(ABRIDGED) The ACS camera on board the Hubble Space Telescope has been used to obtain deep images of the giant elliptical galaxy NGC 3610, a well-established dissipative galaxy merger remnant. These observations supersede previous WFPC2…

Astrophysics · Physics 2008-11-26 Paul Goudfrooij , Francois Schweizer , Diane Gilmore , Bradley C. Whitmore

We present spectroscopic and photometric observations of the eclipsing binary V32 located in the central field of the globular cluster NGC 6397. The variable is a single-line spectroscopic binary with an orbital period of 9.8783d and a…

Astrophysics · Physics 2009-11-13 J. Kaluzny , I. B. Thompson , S. M. Rucinski , W. Krzeminski

Using deep Hubble Space Telescope imaging, color-magnitude diagrams are constructed for the globular clusters 47 Tuc and NGC 6397. As expected, because of its lower metal abundance, the main sequence of NGC 6397 lies well to the blue of…

If NGC 6397 contains a large fraction of "second generation" stars (>70% according to recent analysis), the helium abundance of its stars might also be affected, show some star-to-star variation, and be larger than the standard Big Bang…

Solar and Stellar Astrophysics · Physics 2015-05-14 M. Di Criscienzo , F. D'Antona , P. Ventura

We explore the physics of crystallization in the deep interiors of white dwarf stars using the color-magnitude diagram and luminosity function constructed from proper motion cleaned Hubble Space Telescope photometry of the globular cluster…

Solar and Stellar Astrophysics · Physics 2009-11-13 D. E. Winget , S. O. Kepler , Fabiola Campos , M. H. Montgomery , Leo Girardi , P. Bergeron , Kurtis Williams

We investigate the evolution of binary fractions in star clusters using N-body models of up to 100000 stars. Primordial binary frequencies in these models range from 5% to 50%. Simulations are performed with the NBODY4 code and include a…

Astrophysics · Physics 2009-06-23 Jarrod R. Hurley , Sverre J. Aarseth , Michael M. Shara

We present an observational far-UV (FUV) and near-UV (NUV) study of the core region of the globular cluster NGC 6397. The observations were obtained with the Space Telescope Imaging Spectrograph (STIS, FUV), and the Wide Field Camera 3…

Solar and Stellar Astrophysics · Physics 2017-05-31 Andrea Dieball , Armin Rasekh , Christian Knigge , Michael Shara , David Zurek

In order to interpret the results of complex realistic star cluster simulations, which rely on many simplifying approximations and assumptions, it is essential to study the behavior of even more idealized models, which can highlight the…

Astrophysics · Physics 2009-11-11 D. C. Heggie , M. Trenti , P. Hut

I-band CCD images of a large area of the nearby globular cluster NGC~6397 have been used to construct a surface density profile and two luminosity and mass functions. The surface density profile extends out to 14\arcm from the cluster…

Astrophysics · Physics 2009-10-22 G. A. Drukier , G. G. Fahlman , H. B. Richer , L. Searle , I. Thompson

As a by-product of high-precision, ultra-deep stellar photometry in the Galactic globular cluster NGC 6397 with the Hubble Space Telescope, we are able to measure a large population of background galaxies whose images are nearly point-like.…

NGC 6791 is a well-studied, metal-rich open cluster that is so close to us that can be imaged down to luminosities fainter than that of the termination of its white dwarf cooling sequence, thus allowing for an in-depth study of its white…

Solar and Stellar Astrophysics · Physics 2015-05-28 E. García-Berro , S. Torres , I. Renedo , J. Camacho , L. G. Althaus , A. H. Córsico , M. Salaris , J. Isern

We review new Chandra and HST observations of the core collapsed cluster NGC 6397 as a guide to understanding the compact binary (CB) populations in core collapse globulars. New cataclysmic variables (CVs) and main sequence…

Astrophysics · Physics 2009-11-11 Jonathan E. Grindlay

Bursty star formation in dwarf galaxies can slowly transform a steep dark matter cusp into a constant density core. We explore the possibility that globular clusters (GCs) retain a dynamical memory of this transformation. To test this, we…

Astrophysics of Galaxies · Physics 2019-09-11 M. D. A. Orkney , J. I. Read , James A. Petts , Mark Gieles