Astronomy and Astrophysics – Astrophysics
Scientific paper
1997-01-21
Astronomy and Astrophysics
Astrophysics
9 pages, LaTeX + 1 encapsulated ps figure, uses cupconf.sty (version included). To appear in Advances in Stellar Evolution, ed
Scientific paper
Since the discovery of the Ultraviolet Upturn Phenomenon (``UVX'') in early-type galaxies it has been clear that the stellar populations of such systems contain an unexpected hot component. Recent work has provided strong circumstantial evidence that the stars radiating at short wavelengths (< 2000 Angstrom) is in fact due to hot horizontal branch, post-HB stars and post-AGB stars. We summarize the arguments in favour of this hypothesis. We then derive an estimate for the fraction of all HB stars that must be contributing to the UV upturn phenomenon in the strongest UVX galaxy, NGC 1399, and derive a hot star fraction f_H ~ 0.16.The implication is that UVX arises from a minority fraction of the dominant stellar population. We conclude that the mechanism that produces the UVX is not one that can be explained naturally by the presence of an extremely metal-rich or metal-poor population.
No associations
LandOfFree
The Far-Ultraviolet Radiation from Elliptical Galaxies 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 The Far-Ultraviolet Radiation from Elliptical Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Far-Ultraviolet Radiation from Elliptical Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-125228