The Current Understanding on the UV Upturn
arXiv:0808.0254
Abstract
The unexpected high bump in the UV part of the spectrum found in nearby giant elliptical galaxies, a.k.a. the UV upturn, has been a subject of debate. A remarkable progress has been made lately from the observational side, mainly involving space telescopes. The GALEX UV telescope has been obtaining thousands of giant ellipticals in the nearby universe, while HST is resolving local galaxies into stars and star clusters. An important clue has also been found regarding the origin of hot HB stars, and perhaps of sdB stars. That is, extreme amounts of helium are suspected to be the origin of the extended HB and even to the UV upturn phenomenon. A flurry of studies are pursuing the physics behind it. All this makes me optimistic that the origin of the UV upturn will be revealed in the next few years. I review some of the most notable progress and remaining issues.
Appearing in Bamberg conference on Hot Subdwarf stars and related objects
Cited by in corpus (4)
- Clues on the history of early-type galaxies from SDSS spectra and GALEX photometry
- UV bright red-sequence galaxies: how do UV upturn systems evolve in redshift and stellar mass?
- Environmental Effects on the UV Upturn in Local Clusters of Galaxies
- UV bright red-sequence galaxies: a comparative study between UV upturn and UV weak systems