Integrated UV fluxes and the HB morphology of Globular Clusters

Details Integrated UV fluxes and the HB morphology of Globular Clusters Integrated UV fluxes and the HB morphology of Globular Clusters

Dec 2001

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001aas...199.5611l&link_type=abstract

American Astronomical Society, 199th AAS Meeting, #56.11; Bulletin of the American Astronomical Society, Vol. 33, p.1385

Astronomy and Astrophysics

Astronomy

1

Scientific paper

The UV ( ~ 1500 Å) flux of a globular cluster will be dominated by its blue horizontal branch (HB) population, provided that such a population is present. Thus, the integrated UV - V color of a globular cluster can provide an indication of its HB morphology, without the need to resolve the cluster into a color-magnitude diagram. To date, UV photometry of extragalactic clusters are available for only a few globulars in M31 (e.g. Bohlin et al. 1993, ApJ, 417, 127), but additional UV photometry of extragalactic globulars is soon expected from GALEX (Yi et al. 2001, AAS, 198, 5501), and from STIS FUV-MAMA observations of M87 (HST program 8643). Here we calibrate the relation between UV flux and HB morphology for Galactic globular clusters. The OAO-2 and ANS data tabulated by deBoer (1985, A&A, 142, 321) are supplemented with photometry of 14 globular clusters observed with the Ultraviolet Imaging Telescope (UIT), and a few cluster cores observed with the STIS FUV-MAMA. The UIT data is especially useful since its 40' diameter FOV was sufficient to completely encompass most of the observed clusters, while allowing isolation of hot field and UV-bright stars. We compare the observed Galactic UV color - HB morphology relation with synthetic HB models as a function of age and metallicity. We also estimate the effect of radiative levitation of heavy metals in hot HB stars (e.g. Moehler et al. 2000, , A&A, 360, 120) on the integrated UV flux. This work is funded by STScI grant GO-8358.01.

Affiliated with

Also associated with

No associations

Rating

Integrated UV fluxes and the HB morphology of 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 Integrated UV fluxes and the HB morphology of Globular Clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Integrated UV fluxes and the HB morphology of Globular Clusters will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1231624