An upper limit on the sulphur abundance in HE 1327-2326
نویسندگان
چکیده
منابع مشابه
The Oxygen Abundance of HE 1327 − 2326 1
From a newly obtained VLT/UVES spectrum we have determined the oxygen abundance of HE 1327−2326, the most iron-poor star known to date. UVOH lines yield a 1D LTE abundance of [O/Fe]OH = 3.7 (subgiant case) and [O/Fe]OH = 3.4 (dwarf case). Using a correction of −1.0 dex to account for 3D effects on OH line formation, the abundances are lowered to [O/Fe] = 2.8 and [O/Fe] = 2.5, respectively, whic...
متن کاملAn Upper Limit on the Abundance of Small
I describe the detection of 201 highly significant dips in the count rate of Sco X-1 from a search of some 500 ks of archival RXTE PCA data, which could be caused by TNO occultations. I show that most of these dips are correlated with particle showers in the PCA, suggesting that the dips in count rate result from large amounts of charge built up in the detectors. From the distribution of partic...
متن کاملLow upper limit to methane abundance on Mars.
By analogy with Earth, methane in the Martian atmosphere is a potential signature of ongoing or past biological activity. During the past decade, Earth-based telescopic observations reported "plumes" of methane of tens of parts per billion by volume (ppbv), and those from Mars orbit showed localized patches, prompting speculation of sources from subsurface bacteria or nonbiological sources. Fro...
متن کاملThe Primordial Abundance of He: An Update
We include new data in an updated analysis of helium in low metallicity extragalactic H II regions with the goal of deriving the primordial abundance of He (YP). We show that the new observations of Izotov et al. (ITL) are consistent with previous data. However they should not be taken in isolation to determine YP due to the lack of sufficiently low metallicity points. We use the extant data in...
متن کاملAn empirical calibration of sulphur abundance in ionised gaseous nebulae
We have derived an empirical calibration of the abundance of S/H as a function of the S23 parameter, defined using the bright sulphur lines of [SII] and [SIII]. Contrary to what is the case for the widely used O23 parameter, the calibration remains single valued up to the abundance values observed in the disk HII regions. The calibration is based on a large sample of nebulae for which direct de...
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: Astronomy & Astrophysics
سال: 2012
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201219537