Added in the database the "new" cluster GLIMPSE-C01
http://www.mporzio.astro.it/~marco/gc/cluster_4.php?ggc=GLIMPSE-C01
Greetings,
Marco
Wednesday, May 17, 2006
New feature: improvement of "Top Fifty" page
The "Top Fifty" webpage now has direct links to all listed cluster
http://www.mporzio.astro.it/~marco/gc/vclusters.php
The same is true also for the little "preview" box available in the main page.
Greetings,
Marco
http://www.mporzio.astro.it/~marco/gc/vclusters.php
The same is true also for the little "preview" box available in the main page.
Greetings,
Marco
The Formation Histories of Metal-Rich and Metal-Poor Globular Clusters
Preprint (astro-ph/0605373)
Authors: Stephen E. Zepf
The Formation Histories of Metal-Rich and Metal-Poor Globular Clusters
To appear in the proceedings of the "Globular Clusters: Guides to Galaxies" conference
Abstract:
This review presents the results of ongoing studies of the formation histories of metal-poor and metal-rich globular clusters and their host galaxies. I first discuss the strong observational evidence that the globular cluster systems of most elliptical galaxies have bimodal metallicity distributions. I then focus on new results for metal-poor and metal-rich globular cluster systems. Metal-poor globular clusters are often associated with early structure formation, and I review new constraints on their formation epoch based on the ``bias'' of the number of metal-poor clusters with host galaxy mass. For metal-rich globular clusters, I discuss new results from ongoing optical to near-infrared photometric studies which both confirm an intermediate-age population in NGC 4365 and generally reveal a variety of formation histories for now quiescent ellipticals.
http://babbage.sissa.it/abs/astro-ph/0605373
Authors: Stephen E. Zepf
The Formation Histories of Metal-Rich and Metal-Poor Globular Clusters
To appear in the proceedings of the "Globular Clusters: Guides to Galaxies" conference
Abstract:
This review presents the results of ongoing studies of the formation histories of metal-poor and metal-rich globular clusters and their host galaxies. I first discuss the strong observational evidence that the globular cluster systems of most elliptical galaxies have bimodal metallicity distributions. I then focus on new results for metal-poor and metal-rich globular cluster systems. Metal-poor globular clusters are often associated with early structure formation, and I review new constraints on their formation epoch based on the ``bias'' of the number of metal-poor clusters with host galaxy mass. For metal-rich globular clusters, I discuss new results from ongoing optical to near-infrared photometric studies which both confirm an intermediate-age population in NGC 4365 and generally reveal a variety of formation histories for now quiescent ellipticals.
http://babbage.sissa.it/abs/astro-ph/0605373
Wednesday, May 10, 2006
[preprint] Globular clusters and galaxy formation
Duncan A. Forbes
Globular clusters and galaxy formation
We first discuss recent progress in using the Milky Way globular cluster (GC) system as a `test-bed' for properties derived from integrated spectra and stellar population models. Standard techniques may give rise to spuriously high alpha-element ratios at low metallicities. We then discuss evidence for early epoch (z > 2) formation for most GCs in galaxies today. Recent accretions of GCs (and their host galaxy) make a small contribution but recent mergers form few if any new GCs in today's elliptical galaxies. The early formation of metal-poor GCs and the bimodality seen in GC specific frequency requires a `truncation' which may be due to reionization.
(Globular Clusters - Guides to Galaxies conference)
http://arxiv.org/abs/astro-ph/0605209
Globular clusters and galaxy formation
We first discuss recent progress in using the Milky Way globular cluster (GC) system as a `test-bed' for properties derived from integrated spectra and stellar population models. Standard techniques may give rise to spuriously high alpha-element ratios at low metallicities. We then discuss evidence for early epoch (z > 2) formation for most GCs in galaxies today. Recent accretions of GCs (and their host galaxy) make a small contribution but recent mergers form few if any new GCs in today's elliptical galaxies. The early formation of metal-poor GCs and the bimodality seen in GC specific frequency requires a `truncation' which may be due to reionization.
(Globular Clusters - Guides to Galaxies conference)
http://arxiv.org/abs/astro-ph/0605209
Monday, May 08, 2006
[Preprint] Globular Cluster System evolution in early type galaxies
Preprint
R. Capuzzo-Dolcetta
"Globular Cluster System evolution in early type galaxies"
Globular clusters (GCs) constitute a system which is evolving because of various interactions with the galactic environment. Evolution may be the explanation of many observed features of Globular Cluster Systems (GCSs); the different radial distribution of the GCS and the stellar component of early type galaxies is explained by dynamical friction and tidal effects, this latter acting both on the large scale (that of the bulge-halo stars) and on the small scale (that of the nucleus, often containing a central massive black hole). Merging of quickly orbitally decayed massive GCs leads to formation of a Super Star Cluster (SSC) which enriches the galactic nucleus and is a reservoire of mass-energy for a centrally located black hole
Talk given at the Globular Clusters Guide to Galaxies conference held in Concepcion (Chile) march 6-10 2006
http://arxiv.org/abs/astro-ph/0605162
R. Capuzzo-Dolcetta
"Globular Cluster System evolution in early type galaxies"
Globular clusters (GCs) constitute a system which is evolving because of various interactions with the galactic environment. Evolution may be the explanation of many observed features of Globular Cluster Systems (GCSs); the different radial distribution of the GCS and the stellar component of early type galaxies is explained by dynamical friction and tidal effects, this latter acting both on the large scale (that of the bulge-halo stars) and on the small scale (that of the nucleus, often containing a central massive black hole). Merging of quickly orbitally decayed massive GCs leads to formation of a Super Star Cluster (SSC) which enriches the galactic nucleus and is a reservoire of mass-energy for a centrally located black hole
Talk given at the Globular Clusters Guide to Galaxies conference held in Concepcion (Chile) march 6-10 2006
http://arxiv.org/abs/astro-ph/0605162
Saturday, May 06, 2006
[paper] CCD Photometry of the Globular Cluster ESO 452-SC11
Cornish, Alexis S. M.; Phelps, Randy L.; Briley, Michael M.; Friel, Eileen D.
"CCD Photometry of the Globular Cluster ESO 452-SC11"
The globular cluster ESO 452-SC11 has been observed using Johnson V and Cousins I filters, and point-spread function photometry has been performed. The resulting color-magnitude diagrams were compared to theoretical isochrones to derive the cluster's age, overall chemical composition, and distance modulus. These isochrone models include those published by Girardi et al. and Bergbusch & VandenBerg, with BVRI color-Teff relations as described by VandenBerg & Clem, and Demarque et al. (known as the Yale isochrones). From the Yale isochrones, it is estimated that the cluster has an age of 9-11 Gyr, a metallicity -1.4 dex<=[Fe/H]<=-1.0 dex, and a distance modulus (m-M)V=16.10-16.31 mag, resulting in a heliocentric distance of 7.3-7.5 kpc...
The Astronomical Journal, Volume 131, Issue 5, pp. 2543-2550
ADS Link
"CCD Photometry of the Globular Cluster ESO 452-SC11"
The globular cluster ESO 452-SC11 has been observed using Johnson V and Cousins I filters, and point-spread function photometry has been performed. The resulting color-magnitude diagrams were compared to theoretical isochrones to derive the cluster's age, overall chemical composition, and distance modulus. These isochrone models include those published by Girardi et al. and Bergbusch & VandenBerg, with BVRI color-Teff relations as described by VandenBerg & Clem, and Demarque et al. (known as the Yale isochrones). From the Yale isochrones, it is estimated that the cluster has an age of 9-11 Gyr, a metallicity -1.4 dex<=[Fe/H]<=-1.0 dex, and a distance modulus (m-M)V=16.10-16.31 mag, resulting in a heliocentric distance of 7.3-7.5 kpc...
The Astronomical Journal, Volume 131, Issue 5, pp. 2543-2550
ADS Link
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