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Related papers: A globular cluster in the dwarf galaxy Sextans B

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We present a new technique to determine age and metallicity of old stellar populations (globular clusters and elliptical galaxies) using an iterative principal component analysis on narrow band (Str\"omgren) colors. Our technique is capable…

Astrophysics · Physics 2009-11-11 K. Rakos , J. Schombert , A. Odell

The ages and metallicities of globular clusters play an important role not just in testing models for their formation and evolution but in understanding the assembly history for their host galaxies. Here we use a combination of imaging and…

Astrophysics of Galaxies · Physics 2024-01-26 Christopher Usher , Nelson Caldwell , Ivan Cabrera-Ziri

We present VLT/FORS2 spectroscopic observations of globular clusters (GCs) in five low surface brightness (LSB) dwarf galaxies: KK211 and KK221, which are both dwarf spheroidal satellites (dSph) of NGC 5128, dSph KK84 located close to the…

Astrophysics · Physics 2009-11-13 Thomas H. Puzia , Margarita E. Sharina

Context. The Sagittarius (Sgr) dwarf galaxy is merging with the Milky Way, and the study of its globular clusters (GCs) is important to understand the history and outcome of this ongoing process. Aims. Our main goal is to characterize the…

Astrophysics of Galaxies · Physics 2021-06-30 D. Minniti , M. Gómez , J. Alonso-García , R. K. Saito , E. R. Garro

Globular clusters (GCs) are often used to estimate the dark matter content of galaxies, especially dwarfs, where other kinematic tracers are lacking. These estimates typically assume spherical symmetry and dynamical equilibrium, assumptions…

Astrophysics of Galaxies · Physics 2021-02-17 Jessica E. Doppel , Laura V. Sales , Julio F. Navarro , Mario G. Abadi , Eric W. Peng , Elisa Toloba

NGC 4449 is a nearby Magellanic irregular starburst galaxy with a B-band absolute magnitude of -18 and a prominent, massive, intermediate-age nucleus at a distance from Earth of 3.8 megaparsecs. It is wreathed in an extraordinary neutral…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 R. M. Rich , M. L. M. Collins , C. M. Black , F. M. Longstaff , A. Koch , A. Benson , D. B. Reitzel

We present new empirical estimates of the Delta V_HB_bump parameter for 15 Galactic globular clusters (GGCs) using accurate and homogeneous ground-based optical data. Together with similar evaluations available in the literature, we ended…

We investigate the stellar content of the starburst dwarf galaxy IC10 using accurate and deep optical data collected with the Advanced Camera for Surveys and with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. The…

We present an astrometry and photometry catalogue of globular cluster (GC) candidates detected with HST WFPC2 in a sample of 19 early-type galaxies, appropriate for comparison to the low-mass X-ray binary (LMXB) populations observed with…

Astrophysics · Physics 2008-12-18 Philip J Humphrey

An analysis of ages, metallicities, and [alpha/Fe] ratios of globular cluster systems in early-type galaxies is presented, based on Lick index measurements summarized in Puzia et al. (2004, Paper I of this series). In the light of…

Ages of extragalactic globular clusters can provide valuable insights into the formation and evolution of galaxies. In this contribution the photometric methods of age dating old globular cluster systems are summarised. The spectroscopic…

Astrophysics · Physics 2009-11-07 Thomas H. Puzia

We derive ages, metallicities and [alpha/Fe] ratios from the integrated spectra of 23 globular clusters in M31, by employing multivariate fits to two stellar population models. In parallel we analyze spectra of 21 Galactic globular clusters…

We examine the properties of a previously discovered population of globular clusters in the heart of the rich galaxy cluster Abell 1185 that might be intergalactic in nature. Deep images obtained with the Advanced Camera for Surveys (ACS)…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Michael J. West , Andres Jordan , John P. Blakeslee , Patrick Cote , Michael D. Gregg , Marianne Takamiya , Ronald O. Marzke

From spectrophotometric and chemical evolutionary modelling of interacting and merging galaxies we predict abundances of burst stars and of globular clusters (GCs) that may be formed in strong bursts. Observations of young GCs in merger…

Astrophysics · Physics 2007-05-23 Uta Fritze - v. Alvensleben , Andi Burkert

We build a catalog of massive (M>$8~$M$_\odot$) main sequence stars in the \mbox{metal-poor} ($\sim0.1~$Z$_\odot$) dwarf irregular galaxy Sextans A. HST WFC3 UV photometry in the 275 and 336 nm wideband filters is arranged in a…

Astrophysics of Galaxies · Physics 2026-04-06 Roberto Flores , Elena Fantino , Giuseppina Battaglia , Antonio Aparicio

We present moderate-resolution Keck spectra of nine candidate globular clusters in the possible merger-remnant elliptical galaxy NGC 3610. Eight of the objects appear to be bona fide globular clusters of NGC 3610. We find that two of the…

With the Wide Field Planetary Camera 2 (WFPC2) on the Hubble Space Telescope, we have discovered in M4 (NGC 6121, C 1620-264) the first extensive sequence of cooling white dwarfs seen in a globular cluster. Adopting a distance modulus of…

We have performed a spectroscopic study of globular clusters (GCs) in the giant elliptical NGC 5128 using the 2dF facility at the Anglo-Australian telescope. We obtained integrated optical spectra for a total of 254 GCs, 79 of which are…

Galactic globular clusters are not simple stellar populations. And nothing is simple in their study, basically because we try to reconstruct chains of events that occurred at redshift z > 2-3 by observing these objects at z=0, after a…

Astrophysics of Galaxies · Physics 2016-11-16 Eugenio Carretta

Observations of the high energy sky, mainly with the INTEGRAL satellite, have raised new questions about the formation and evolution of High Mass X-ray Binaries (HMXBs). The number of detected HMXBs of different types is now high enough to…

High Energy Astrophysical Phenomena · Physics 2013-02-18 A. Coleiro , S. Chaty