Globular cluster ages determined from the Oosterhoff period-metallicity effect using oxygen-enhanced isochrones. III

Details Globular cluster ages determined from the Oosterhoff period-metallicity effect using oxygen-enhanced isochrones. III Globular cluster ages determined from the Oosterhoff period-metallicity effect using oxygen-enhanced isochrones. III

Aug 1993

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993aj....106..719s&link_type=abstract

Astronomical Journal (ISSN 0004-6256), vol. 106, no. 2, p. 719-725.

Astronomy and Astrophysics

Astronomy

77

Chronology, Galactic Clusters, Globular Clusters, Metallicity, Stellar Luminosity, Variable Stars, Cosmology, Main Sequence Stars, Stellar Magnitude, Supernovae

Scientific paper

The new brighter calibration of absolute luminosities of RR Lyrae stars by about 0.25 mag as a function of metallicity via the Oosterhoff period effect gives a revised age of the Galactic globular cluster system as 14 Gyr when used with the oxygen-enhanced main-sequence termination models of Bergbush and VandenBerg (1992). There is no correlation of cluster age with metallicity. The presence or absence of age differences between any two clusters is neither proof nor disproof of the Eggen-Lynden Bell-Sandage model of the formation of the Galaxy by collapse. If there were different density regimes within the initial density fluctuation that was the protogalaxy, then there has been a hierarchy of collapse times for the various parts of the present Galaxy. The age of the universe is 15 Gyr, based on the age of the Galaxy at 14 Gyr, to which 1 Gyr is added for the gestation time of the galaxies. The ratio of this age to the inverse Hubble constant with H(0) about 45 km/s Mpc, based on a recent concordant determination using supernovae of type Ia, is close to the critical value of 2/3 required if the deceleration is caused by a mean density just equal to that needed for closure. For the first time, these new data give the possibility that Omega = 1 from this timing test.

Affiliated with

Also associated with

No associations

Rating

Globular cluster ages determined from the Oosterhoff period-metallicity effect using oxygen-enhanced isochrones. III 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 Globular cluster ages determined from the Oosterhoff period-metallicity effect using oxygen-enhanced isochrones. III, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Globular cluster ages determined from the Oosterhoff period-metallicity effect using oxygen-enhanced isochrones. III will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1490897