The UV Upturn: From M32 to Distant Clusters
نویسندگان
چکیده
منابع مشابه
The UV Upturn: From M32 to Distant Clusters
I review the observational constraints on the stars responsible for the upturn in the UV spectra of ellipticals, ranging from galaxies in the local Universe to distant clusters. In nearby galaxies, this UV upturn is produced by a minority population of extreme horizontal branch (EHB) stars, with the large variations observed in the UV-to-optical flux ratio driven by variations in the number of ...
متن کاملThe Current Understanding on the UV Upturn
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...
متن کاملUV Upturn in Elliptical Galaxies: Theory
I review the current theoretical understanding on the UV upturn phenomenon in early-type galaxies.
متن کاملA Binary Model for the UV-upturn of Elliptical Galaxies
The discovery of an excess of light in the far-ultraviolet (UV) in 1969 in elliptical galaxies was a major surprise. While it is now clear that this UV excess (UV-upturn) is probably caused by an old population of helium-burning stars. Han et al (2002, 2003) proposed a binary model for the formation of hot subdwarfs (helium burning stars) and the model can reproduce the observations in our Gala...
متن کاملOn the Origin of the UV Upturn in Elliptical Galaxies . I . Sensitivity of UV Population Synthesis to Various Input Parameters
We present models of the late stages of stellar evolution intended to explain the " UV upturn " phenomenon in elliptical galaxies. Such models are sensitive to values of a number of poorly-constrained physical parameters, including metallicity, age, stellar mass loss, helium enrichment, and the distribution of stars on the zero age horizontal branch (HB). We explore the sensitivity of the resul...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Astrophysics and Space Science
سال: 2004
ISSN: 0004-640X
DOI: 10.1023/b:astr.0000044324.60467.d2