Globular Clusters in nearby Galaxy Clusters
نویسنده
چکیده
The discovery of a large population of intra-cluster star clusters in the central region of the Hydra I and Centaurus galaxy clusters is presented. Based on deep VLT photometry (V, I), many star clusters have been identified not only around the early-type galaxies, but also in the intra-cluster field, as far as 250 kpc from the galaxy centres. These intra-cluster globulars are predominantly blue, with a siginificant fraction being even bluer than the metal-poor halo clusters around massive galaxies. When interpreted as a metallicity effect they would have iron abundances around [Fe/H]≃ −2 dex. However, they might also be relatively young clusters which could have formed in tidal tails during recent interactions of the central galaxies.
منابع مشابه
Are Globular Clusters the Remnant Nuclei of Progenitor Disk Galaxies?
The globular cluster system of a typical spheroidal galaxy makes up about 0.25% of the total galaxy mass (McLaughlin 1999). This is roughly the same mass fraction as contained in the nuclear star cluster (or stellar nucleus) present in most nearby low-mass galaxies. Motivated by this “coincidence”, this Letter discusses a scenario in which globular clusters of present-day galaxies are the survi...
متن کاملGlobular Clusters in the Sombrero Galaxy ( NGC 4594 )
The Sombrero galaxy, NGC 4594, contains the most numerous globular cluster system of any nearby spiral. It is an ideal candidate in which to study the globular clusters and contrast them with those in Local Group spirals. Here we present B and I imaging from the CTIO Schmidt telescope which gives a field-of-view of 31 ′ × 31 ′ . Using DAOPHOT we have detected over 400 globular clusters and deri...
متن کاملGlobular Clusters in the Sombrero Galaxy (NGC 4594) 1,2
The Sombrero galaxy, NGC 4594, contains the most numerous globular cluster system of any nearby spiral. It is an ideal candidate in which to study the globular clusters and contrast them with those in Local Group spirals. Here we present B and I imaging from the CTIO Schmidt telescope which gives a field-of-view of 31 ′ × 31 ′ . Using DAOPHOT we have detected over 400 globular clusters and deri...
متن کاملDynamical Evolution of Globular Clusters in Hierarchical Cosmology
We probe the evolution of globular clusters that could form in giant molecular clouds within high-redshift galaxies. Numerical simulations demonstrate that the large and dense enough gas clouds assemble naturally in current hierarchical models of galaxy formation. These clouds are enriched with heavy elements from earlier stars and could produce star clusters in a similar way to nearby molecula...
متن کاملSome Global Characteristics of the Galactic Globular Cluster System
The relations between the luminosities M V , the metallicities [F e/H], the Galacto-centric radii R, and the central concentration indices c of Galactic globular clusters are discussed. It is found that the most luminous clusters rarely have collapsed cores. The reason for this might be that the core collapse time scales for such populous clusters are greater than the age of the Galaxy. Among t...
متن کاملSED, Metallicity and Age of Halo Globular Clusters in M33
In this paper we study the properties of ten halo globular clusters in the nearby spiral galaxy M33. CCD images of M33 were obtained as a part of the BATC Colour Survey of the sky in 13 intermediate-band filters from 3800 to 10000Å. By aperture photometry, we obtain the spectral energy distributions (SEDs) of these globular clusters. We estimate the ages of our sample clusters by comparing the ...
متن کامل