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The Metallicity Distribution of Intracluster Stars in Virgo

Authors :
Williams, Benjamin F.
Ciardullo, Robin
Durrell, Patrick R.
Vinciguerra, Matt
Feldmeier, John J.
Jacoby, George H.
Sigurdsson, Steinn
von, Ted
Ferguson, Henry C.
Tanvir, Nial R.
Arnaboldi, Magda
Gerhard, Ortwin
Aguerri, Alfonso L.
Freeman, Ken
Source :
The Astrophysical Journal; February 2007, Vol. 656 Issue: 2 p756-769, 14p
Publication Year :
2007

Abstract

We have used the Hubble Space Telescope's Advanced Camera for Surveys (ACS) to detect and measure ~5300 stars in a single intracluster field in the Virgo Cluster. By performing F606W and F814W photometry on these stars, we have determined their metallicity distribution function and constrained the types of stars present in this portion of Virgo's intracluster space. Based on the small number of stars detected that were brighter than the red giant branch (RGB) tip, we suggest that in this region, Virgo's intracluster stars are mostly old ([?]10 Gyr). Through analysis of the RGB stars themselves, we determine that the population contains the full range of metallicities probed (-2.3 [?] [M/H] [?] 0.0). We also present evidence that the younger ([?]10 Gyr) component of the population is more metal-rich, with [M/H] > -0.5. The spatial distribution of the most metal-poor stars in the field shows significantly more structure than that of the metal-rich stars, indicating that the intracluster population is not well mixed. We discuss the implications that these observations have for the production of intracluster stars and the dynamical evolution of the Virgo Cluster.

Details

Language :
English
ISSN :
0004637X and 15384357
Volume :
656
Issue :
2
Database :
Supplemental Index
Journal :
The Astrophysical Journal
Publication Type :
Periodical
Accession number :
ejs18565272