Astronomy and Astrophysics – Astrophysics
Scientific paper
1999-06-08
Astronomy and Astrophysics
Astrophysics
4 pages, 2 figures, LaTex ps files, in Spectro-Photometric Dating of Stars & Galaxies, in press
Scientific paper
The UV upturn phenomenon observed in elliptical galaxies is attractive for its potential value as an age indicator of old stellar systems. We present our most recent population models for the UV evolution of elliptical galaxies. We confirm that the dominant UV sources are either metal-poor or metal-rich hot horizontal-branch (HB) stars in local giant ellipticals, but we also note that the contribution from post-asymptotic-giant-branch (PAGB) stars overwhelms the UV spectrum at higher redshifts (look-back times). The model UV spectral energy distribution (SED) is therefore strongly affected by the current uncertainty of the mean mass of PAGB stars at higher redshifts. Fortunately, our models suggest that the far-UV observations at z > 0.35 could produce strong constraint on the PAGB mass, while observations at could produce strong constraint on the PAGB mass, while observations at lower redshifts (0.15 < z < 0.30) would still provide constraints on the models on the origin of the UV upturn. Future observations of ellipticals from the STIS/HST and planned GALEX space UV facility will provide crucial database required for more concrete calibration of our UV dating techniques for old stellar systems.
Lee Young-Wook
Park Jae-Heung
Woo Jong-Hak
Yi Sun
No associations
LandOfFree
Spectrophotometric Dating of Elliptical Galaxies in the Ultraviolet 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 Spectrophotometric Dating of Elliptical Galaxies in the Ultraviolet, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectrophotometric Dating of Elliptical Galaxies in the Ultraviolet will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-653682