Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-10-09
Astrophys.J.633:821-827,2005
Astronomy and Astrophysics
Astrophysics
10 pages, 5 figures (ApJ, in press)
Scientific paper
10.1086/468178
Using the Hubble Space Telescope, we have resolved individual red-giant branch stars in the halos of eight nearby spiral galaxies. The fields lie at projected distances between 2 and 13 kpc along the galaxies' minor axes. The data set allows a first look at the systematic trends in halo stellar populations. We have found that bright galaxies tend to have broad red-giant branch star color distributions with redder mean colors, suggesting that the heavy element abundance spread increases with the parent galaxy luminosity. The mean metallicity of the stellar halo, estimated using the mean colors of red-giant branch stars, correlates with the parent galaxy luminosity. The metallicity of the Milky Way halo falls nearly 1 dex below this luminosity-metallicity relation, suggesting that the halo of the Galaxy is more the exception than the rule for spiral galaxies; i.e., massive spirals with metal-poor halos are unusual. The luminosity-halo stellar abundance relation is consistent with the scaling relation expected for stellar systems embedded in dominant halos, suggesting that the bulk of the halo stellar population may have formed in situ.
Brown Ted M.
Ferguson Henry C.
Mouhcine Mustapha
Rich Robert Michael
Smith Ed. T.
No associations
LandOfFree
Halos of Spiral Galaxies. II. halo metallicity-luminosity relation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Halos of Spiral Galaxies. II. halo metallicity-luminosity relation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Halos of Spiral Galaxies. II. halo metallicity-luminosity relation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-146651