Can globular clusters be as young as 10 Gyr?--The Uncertainties in the Age of Globular Clusters from Their Helium Abundance and Mass Loss

Details Can globular clusters be as young as 10 Gyr?--The Uncertainties in the Age of Globular Clusters from Their Helium Abundance and Mass Loss Can globular clusters be as young as 10 Gyr?--The Uncertainties in the Age of Globular Clusters from Their Helium Abundance and Mass Loss

1994-09-29

arxiv.org/abs/astro-ph/9409082v2

Astronomy and Astrophysics

Astrophysics

revtex file 27 pages, six figures upon request to shi@astro. queensu.ca, or ftp at oddjob.uchicago.edu:/pub/globular. Submitte

Scientific paper

The age of globular clusters inferred from observations depends sensitively on assumptions such as the initial helium abundance and the mass loss rate. A high helium abundance (e.g., $Y\approx$0.28), as well as an inclusion of helium diffusion and oxygen-enhancement in stellar models, can lower the current age estimate for metal-poor globular clusters from 14$\pm 1.5$ Gyr to about 11$\pm 1$ Gyr, significantly relaxing the constraints on the Hubble constant, allowing values as high as 60km/sec/Mpc for a universe with the critical density and 90km/sec/Mpc for a baryon-only universe. The uncertainties of a high helium abundance and an instability strip induced mass loss near the turn-off in globular clusters are discussed. Ages lower than 10 Gyr are not possible even with the operation of both of these mechanisms unless the initial helium abundance in globular clusters is $>0.28$, which can hardly be accomodated by indirect inferences of helium abundances in globular clusters.

Affiliated with

Also associated with

No associations

Rating

Can globular clusters be as young as 10 Gyr?--The Uncertainties in the Age of Globular Clusters from Their Helium Abundance and Mass Loss 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 Can globular clusters be as young as 10 Gyr?--The Uncertainties in the Age of Globular Clusters from Their Helium Abundance and Mass Loss, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Can globular clusters be as young as 10 Gyr?--The Uncertainties in the Age of Globular Clusters from Their Helium Abundance and Mass Loss will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-241325