Suspected globular clusters in the Fornax I cluster of galaxies

Both the radial and the velocity distributions of galaxies within rich clusters are well described by the isothermal distribution (e.g. Lewis 1978 and 1979). It is tempting to ascribe this apparently relaxed state to the operation of Lynden-BeU’s (1967) violent relaxation mechanism, during the initial coherent collapse on the proto-cluster, after it brakes itself against the universal expansion. This scenario explains the isothermal distribution observed in elliptical galaxies and globular clusters. When applied to a cluster of galaxies made up of baryons, however, the timescale for the scenario is comparable with the Hubble time H−1. The situation changes if most of the cluster mass is contributed by neutrinos.

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Intergalactic Globular Clusters

Highlights of Astronomy ◽

10.1017/s1539299600015513 ◽

2005 ◽

Vol 13 ◽

pp. 175-176

Author(s):

Michael J. West ◽

Patrick Côté ◽

Henry C. Ferguson ◽

Michael D. Gregg ◽

Andrés Jordán ◽

...

Keyword(s):

Globular Cluster ◽

Globular Clusters ◽

Virgo Cluster ◽

Evolution Of Galaxies ◽

Cluster Of Galaxies

AbstractWe confirm and extend our previous detection of a population of intergalactic globular clusters in Abell 1185, and report the first discovery of an intergalactic globular cluster in the nearby Virgo cluster of galaxies. The numbers, colors and luminosities of these objects can place constraints on their origin, which in turn may yield new insights to the evolution of galaxies in dense environments.

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Ultra compact objects in the Fornax cluster of galaxies: Globular clusters or dwarf galaxies?

Astronomy and Astrophysics ◽

10.1051/0004-6361:20011833 ◽

2002 ◽

Vol 383 (3) ◽

pp. 823-837 ◽

Cited By ~ 93

Author(s):

S. Mieske ◽

M. Hilker ◽

L. Infante

Keyword(s):

Globular Clusters ◽

Dwarf Galaxies ◽

Compact Objects ◽

Cluster Of Galaxies ◽

Fornax Cluster

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Astroinformatics-based search for globular clusters in the Fornax Deep Survey

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2801 ◽

2019 ◽

Vol 490 (3) ◽

pp. 4080-4106

Author(s):

G Angora ◽

M Brescia ◽

S Cavuoti ◽

M Paolillo ◽

G Longo ◽

...

Keyword(s):

Globular Clusters ◽

Multidisciplinary Approach ◽

Feature Selection Method ◽

Principal Component ◽

Selection Method ◽

Neural Gas ◽

The Core ◽

Cluster Of Galaxies ◽

Deep Survey ◽

Fornax Cluster

ABSTRACT In the last years, Astroinformatics has become a well-defined paradigm for many fields of Astronomy. In this work, we demonstrate the potential of a multidisciplinary approach to identify globular clusters (GCs) in the Fornax cluster of galaxies taking advantage of multiband photometry produced by the VLT Survey Telescope using automatic self-adaptive methodologies. The data analysed in this work consist of deep, multiband, partially overlapping images centred on the core of the Fornax cluster. In this work, we use a Neural Gas model, a pure clustering machine learning methodology, to approach the GC detection, while a novel feature selection method (ΦLAB) is exploited to perform the parameter space analysis and optimization. We demonstrate that the use of an Astroinformatics-based methodology is able to provide GC samples that are comparable, in terms of purity and completeness with those obtained using single-band HST data and two approaches based, respectively, on a morpho-photometric and a Principal Component Analysis using the same data discussed in this work.

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Recent Advances in High Dispersion Spectroscopy of Globular Cluster Stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900035610 ◽

1988 ◽

Vol 132 ◽

pp. 525-530

Author(s):

Raffaele G. Gratton

Keyword(s):

Globular Cluster ◽

Globular Clusters ◽

High Dispersion ◽

Photographic Material ◽

Recent Advances ◽

Metal Abundances ◽

Ccd Detectors ◽

Major Progress

The use CCD detectors has allowed a major progress in abundance derivations for globular cluster stars in the last years. Abundances deduced from high dispersion spectra now correlates well with other abundance indicators. I discuss some problems concerning the derivation of accurate metal abundances for globular clusters using high dispersion spectra from both the old photographic and the most recent CCD data. The discrepant low abundances found by Cohen (1980), from photographic material for M71 giants, are found to be due to the use of too high microturbulences.

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