Distances and Absolute Ages of Galactic Globular Clusters from Subdwarf Parallaxes

Details Distances and Absolute Ages of Galactic Globular Clusters from Subdwarf Parallaxes Distances and Absolute Ages of Galactic Globular Clusters from Subdwarf Parallaxes

Aug 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997esasp.402..651g&link_type=abstract

Proceedings of the ESA Symposium `Hipparcos - Venice '97', 13-16 May, Venice, Italy, ESA SP-402 (July 1997), p. 651-656

Physics

4

Scientific paper

High precision trigonometric parallaxes from the Hipparcos satellite and accurate metal abundances ([Fe/H], [O/Fe], and [alpha/Fe]) from high resolution spectroscopy for about 30 local subdwarfs have been used to derive distances and ages for a carefully selected sample of nine globular clusters. We find that Hipparcos parallaxes are smaller than the corresponding ground-based measurements leading, to a longer distance scale (~ 0.2 mag) and to ages ~ 2.8 Gyr younger. The relation between the zero age horizontal branch (ZAHB) absolute magnitude and metallicity for the nine programme clusters is: M_V(ZAHB) = (0.22 +/- 0.09)([Fe/H]}+1.5) + (0.48 +/- 0.04). The corresponding Large Magellanic Cloud distance modulus is (m-M)_0=18.61 +/- 0.07. The age of the bona fide old globular clusters (Oosterhoff II and Blue Horizontal Branch) based on the absolute magnitude of the turn-off is: age = 11.8 (+2.1 - -2.5) Gyr. The present age of globular clusters no longer conflicts with standard inflationary models for the Universe.

Affiliated with

Also associated with

No associations

Rating

Distances and Absolute Ages of Galactic Globular Clusters from Subdwarf Parallaxes 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 Distances and Absolute Ages of Galactic Globular Clusters from Subdwarf Parallaxes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Distances and Absolute Ages of Galactic Globular Clusters from Subdwarf Parallaxes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1879405