Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-01-21
Astronomy and Astrophysics
Astrophysics
many pages, 43 postscript figures, submitted to ApJ
Scientific paper
10.1086/424832
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular we study the influence of various systematic uncertainties, both observational and theoretical, on the determination of the cluster age from the white dwarf cooling sequence. These include uncertainties in the distance to the cluster and the extinction along the line of sight, as well as the white dwarf mass, envelope and core compositions and the white dwarf --main sequence mass relation. We find that fitting to the full two-dimensional colour-magnitude diagram offers a more robust method for age determination than the traditional method of fitting the one-dimensional white dwarf luminosity function. After taking into account the various uncertainties, we find a best fit age of 12.1 Gyr, with a 95% lower limit of 10.3 Gyr. We also perform fits using two other sets of cooling models from the literature. The models of Chabrier et al (2000) yield an encouragingly similar result, although the models of Salaris et al (2000) do not provide as good a fit. Our results support our previous determination of a delay between the formation of the Galactic halo and the onset of star formation in the Galactic disk.
Brewer James
Currie Thayne
Fahlman Greg
Gibson Brad
Hansen Brad
No associations
LandOfFree
HST Observations of the White Dwarf Cooling Sequence of M4 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 HST Observations of the White Dwarf Cooling Sequence of M4, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and HST Observations of the White Dwarf Cooling Sequence of M4 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-384436