On the magnitude difference between the main sequence turn off and the red giant branch bump in Galactic globular clusters

Details On the magnitude difference between the main sequence turn off and the red giant branch bump in Galactic globular clusters On the magnitude difference between the main sequence turn off and the red giant branch bump in Galactic globular clusters

2010-12-02

arxiv.org/abs/1012.0419v1

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

6 pages, 4 figures, Astronomy & Astrophysics, in press

Scientific paper

We present new measurements of the magnitude of the main sequence turn off and the red giant branch bump in the luminosity function of a sample of Galactic globular clusters with updated estimates of [Fe/H] and [$\alpha$/Fe], employing photometric data collected with the Advanced Camera for Survey on board the HST. We compare measured and predicted values of the magnitude difference between these two features, a rarely employed diagnostic of the internal structure of low-mass stars at the beginning of their red giant evolution. Our analysis discloses a clear discrepancy between theory and observations, the theoretical red giant branch bump magnitudes being too bright by on average $\sim0.2$~mag. This corroborates results from the more widely studied magnitude difference between horizontal branch and red giant bump, avoiding the well known problems associated to the determination of the horizontal branch level from colour magnitude diagrams, and to uncertainties in the luminosity of horizontal branch stellar models. We briefly discuss several potential solutions of this discrepancy.

Affiliated with

Also associated with

No associations

Rating

On the magnitude difference between the main sequence turn off and the red giant branch bump in Galactic globular clusters 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 On the magnitude difference between the main sequence turn off and the red giant branch bump in Galactic globular clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the magnitude difference between the main sequence turn off and the red giant branch bump in Galactic globular clusters will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-603659