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Related papers: Galaxy threshing and the formation of ultra-compac…

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Most ultra-compact dwarf galaxies (UCDs) and very massive globular clusters reside in nearby galaxy clusters or around nearby giant galaxies. Due to their distance (>Mpc) and compactness (r_eff<100pc) they are barely resolved, and thus it…

Astrophysics of Galaxies · Physics 2015-12-24 Michael Hilker

We report the discovery of 271 previously undetected dwarf galaxies in the outer Fornax cluster regions at radii $r_{\rm vir}/4<\!r\!<r_{\rm vir}/2$ using data from the Next Generation Fornax Survey (NGFS) with deep coadded $u'$, $g'$ and…

The origin of ultra-compact dwarf galaxies (UCDs) is not yet clear. One possible formation path of UCDs is the threshing of a nucleated elliptical dwarf galaxy (dE, N), however, it remains unclear how such massive nuclear stellar systems…

Astrophysics of Galaxies · Physics 2018-05-16 Morgan Goodman , Kenji Bekki

The smallest dwarf galaxies are the most straight forward objects in which to study star formation processes on a galactic scale. They are typically single cell star forming entities, and as small potentials in orbit around a much larger…

Astrophysics · Physics 2011-08-23 Eline Tolstoy

Recent photometric observations by the {\it Hubble Space Telescope (HST)} have revealed the physical properties of stellar galactic nuclei in nucleated dwarf galaxies in the Virgo cluster of galaxies. In order to elucidate the formation…

Astrophysics · Physics 2009-11-11 Kenji Bekki , Warrick J. Couch , Yasuhiro Shioya

We search for hints to the origin and nature of compact stellar systems in the magnitude range of ultracompact dwarf galaxies in deep wide-field imaging data of the Fornax cluster core. We visually investigate a large sample of 355…

Astrophysics of Galaxies · Physics 2016-05-11 Carolin Wittmann , Thorsten Lisker , Anna Pasquali , Michael Hilker , Eva K. Grebel

Studies of low surface brightness (LSB) galaxies in nearby clusters have revealed a sub-population of extremely diffuse galaxies with central surface brightness $\mu_{0,g'}$ > 24 mag arcsec$^{-2}$ and effective radius between 1.5 kpc <…

Nuclear star clusters (NSCs) are the densest stellar systems in the Universe. They can be found at the center of all galaxy types, but tend to favor galaxies of intermediate stellar mass around 10$^9\,$M$_{\odot}$[1, 2]. Currently, two main…

The origin of ultracompact dwarfs (UCDs), a class of compact stellar systems discovered two decades ago, still remains a matter of debate. Recent discoveries of central supermassive black holes in UCDs likely inherited from their massive…

The origin of ultracompact dwarf (UCD) galaxies, compact extragalactic stellar systems, is still a puzzle for present galaxy formation models. We present the comprehensive analysis of high resolution multi-object spectroscopic data for a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Igor Chilingarian , Steffen Mieske , Michael Hilker , Leopoldo Infante

Ultra-compact dwarf galaxies (UCDs) share many properties with globular clusters (GCs) and are found in similar environments. A large sample of UCDs and GCs around NGC 1399, the central giant elliptical of the Fornax galaxy cluster, is used…

Astrophysics of Galaxies · Physics 2016-10-26 C. Schulz , M. Hilker , P. Kroupa , J. Pflamm-Altenburg

NGC 1380 is a lenticular galaxy located near the centre of the Fornax Cluster northeast of NGC 1399. The globular cluster system of this galaxy was previously studied only from the ground. Recent studies of similar early-type galaxies,…

Astrophysics · Physics 2009-11-13 A. L. Chies-Santos , B. X. Santiago , M. G. Pastoriza

We present newly discovered dwarf galaxy candidates in deep and wide-field images of NGC 1291 obtained with the Korea Microlensing Telescope Network. We identify 15 dwarf galaxy candidates by visual inspection. Using imaging simulations, we…

We present results from the first numerical analysis to support the hypothesis, first proposed in Coleman et al. (2004), that the Fornax dwarf galaxy was formed from the minor merging of two dwarfs about 2 Gyr ago. Using orbits for the…

Astrophysics of Galaxies · Physics 2015-06-05 C. Yozin , K. Bekki

The study of dwarf galaxies in groups is a powerful tool for investigating galaxy evolution, chemical enrichment and environmental effects on these objects. Here we present results obtained for dwarf galaxies in the Centaurus A complex, a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 D. Crnojević , E. K. Grebel , A. A. Cole , A. Koch , M. Rejkuba , G. Da Costa , H. Jerjen

We review some properties of ultracompact dwarf galaxies (UCDs) in Fornax and of their brighter counterparts in Abell 1689, among which are two M32 twins, and discuss various possible UCD formation scenarios. We note that it is…

Astrophysics · Physics 2009-11-11 S. Mieske , M. Hilker , L. Infante

We compare the predictions of a semi-analytic model for ultra-compact dwarf galaxy (UCD) formation by tidal stripping to the observed properties of globular clusters (GCs) and UCDs in the Fornax and Virgo clusters. For Fornax we find the…

Astrophysics of Galaxies · Physics 2016-03-23 Joel Pfeffer , Michael Hilker , Holger Baumgardt , Brendan F. Griffen

Over the past five years, searches in Sloan Digital Sky Survey data have more than doubled the number of known dwarf satellite galaxies of the Milky Way, and have revealed a population of ultra-faint galaxies with luminosities smaller than…

Cosmology and Nongalactic Astrophysics · Physics 2009-02-23 James S. Bullock , Manoj Kaplinghat , Andrew Fruchter , Marla Geha , Joshua D. Simon , Louis E. Strigari , Beth Willman

We use the Millennium II cosmological simulation combined with the semi-analytic galaxy formation model of Guo et al. (2011) to predict the contribution of galactic nuclei formed by the tidal stripping of nucleated dwarf galaxies to…

Astrophysics of Galaxies · Physics 2015-06-22 Joel Pfeffer , Brendan F. Griffen , Holger Baumgardt , Michael Hilker

Clues to the formation and evolution of Nuclear Star Clusters (NSCs) lie in their stellar populations. However, these structures are often very faint compared to their host galaxy, and spectroscopic analysis of NSCs is hampered by…