Color‐Magnitude Diagrams of Resolved Stars in Virgo Cluster Dwarf Galaxies
- 10 November 2006
- journal article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 651 (2), 822-834
- https://doi.org/10.1086/507825
Abstract
The Advanced Camera for Surveys (ACS) on HST has been used to image two fields in the core of the Virgo cluster that contain a number of dwarf elliptical galaxies. The combined F555W and F814W images have resolved red giant stars in these galaxies, down to 1 mag below the giant branch tip. Two of the galaxies were targeted because of their extremely low central surface brightnesses (Bo > 27.0), thus the successful resolution into stars confirms the existence of such tenuous galaxies. Red giant stars were also found that are not ostensibly associated with any galaxy. Color-magnitude diagrams in V and I have been derived and used to derive distances and metallicities via the magnitude and mean color of the red giant branch tip. The mean abundances of stars in the dwarfs range from -1.2 [Fe/H] < -2.4, and fall along the relation between galaxy luminosity and metallicity found for Local Group and M81 group dwarf ellipticals. The mean distance modulus of the six Virgo galaxies is 31.0 +/- 0.05, or 16.1 +/- 0.4 Mpc, whereas that for the intracluster stars in those fields is 31.2 +/- 0.09 (17.4 +/- 0.7 Mpc).Comment: 18 pages, 11 figures. Full resolution is available at http://cfa-www.harvard.edu/~caldwell/outgoing/virgo_dwarfs.ps.gThis publication has 36 references indexed in Scilit:
- The Stellar Populations of dE Galaxies in Nearby GroupsPublications of the Astronomical Society of Australia, 2004
- Galaxy Populations and Evolution in Clusters. III. The Origin of Low-Mass Galaxies in Clusters: Constraints from Stellar PopulationsThe Astronomical Journal, 2003
- The M31 Dwarf Spheroidal Companion Andromeda V: [CLC][ITAL]g[/ITAL][/CLC]′, [CLC][ITAL]r[/ITAL][/CLC]′, and [CLC][ITAL]i[/ITAL][/CLC]′ Imaging with the Gemini Multi-Object Spectrograph on Gemini NorthThe Astronomical Journal, 2002
- Dwarf Elliptical Galaxies in the M81 Group: The Structure and Stellar Populations of BK5N and F8D1The Astronomical Journal, 1998
- The Dwarf Spheroidal Companions to M31: WFPC2 Observations of Andromeda IThe Astronomical Journal, 1996
- SExtractor: Software for source extractionAstronomy and Astrophysics Supplement Series, 1996
- The dwarf spheroidal companions to M31 - A color-magnitude diagram for And IIIThe Astronomical Journal, 1993
- Standard globular cluster giant branches in the (M[SUB]I,/V-I/sub[/SUB] O) planeThe Astronomical Journal, 1990
- Studies of the Virgo cluster. VI - Morphological and kinematical structure of the Virgo clusterThe Astronomical Journal, 1987
- Studies of the Virgo Cluster. II - A catalog of 2096 galaxies in the Virgo Cluster area. V - Luminosity functions of Virgo Cluster galaxiesThe Astronomical Journal, 1985