Surveys of nearby field stars with extreme kinematics or extreme metallicities can also contribute to the study of disk versus halo stars, but in this case the interpretation is difficult because of selection effects. Surveys of faint stars in situ at large distances show great promise for studies...
(N=67) of recently studied FGK-type dwarf stars in the solar neighbourhood including different populations (Nissen and Schuster 2010, Ramirez et al. 2012), namely LH (N=24, low-伪 halo), HH (N=25, high-伪 halo), KD (N=16, thick disk), and OL (N=2, globular cluster outliers)....
Stars with "intermediate" kinematics (P 1 P 2 P 3 > 0.5) show a large star-to-star scatter in [O/Fe]-[Fe/H], but most of it is due to stars with Galactocentric rotational velocity V –1; halo stars with V > –200kms–1 follow an [O/Fe]-[Fe/H] relation with almost no ...
starsstellar composition/ Mg abundancesMg I linesFe II lineslog gravityHipparcos parallaxesNLTE effectsformation of the Mg I lineA differential analysis of the magnesium abundances in 61 F-K dwarfs and subgiants with metallicities 2.6<[Fe/H]<+0.2 is performed based on published observational data...
5.Background stars are also visible as the otherwise overwhelming sunlight is blocked by the coronograph's occultingdisk. 5.在影像中还能看到背景恒星,另外强烈的太阳光被日冕观测仪的掩 遮挡了。 评价该例句:好评差评指正 6.Rupturedisksrelieve overpressure in cylinders that may result from an external ...
Explaining the Ba, Y, Sr, and Eu abundance scatter in metal-poor halo stars: Constraints to the r-process Context. Thanks to the heroic observational campaigns carried out in recent years we now have large samples of metal-poor stars for which measurements of d... G Cescutti,C Chiappini ...
The assembly of our Galaxy can be reconstructed using the motions and chemistry of individual stars1,2. Chemo-dynamical studies of the stellar halo near the Sun have indicated the presence of multiple components3, such as streams4 and clumps5, as well as
Bar-mode instability in a Maclaurin disk of stars: the effect of an inhomogeneous halo. 来自 ResearchGate 喜欢 0 阅读量: 20 作者: SV Chalov 摘要: Translation from Astron. Zh. 63, No.4, 635-642 (Russian) (1986; Zbl 0603.70016). 关键词: Stellar Disks:Stability 年份: 1986 ...
2) In an log(Be/H) vs [alpha/Fe] diagram, the halo stars separate into two components; one is consistent with predictions of evolutionary models, while the other has too high alpha and Be abundances and is chemically indistinguishable from thick disk stars. This suggests that the halo is ...
including estimating the core radius of the dark halo (Sparke and Casertano 1988), the disk metallicity gradient (which is a signature of the history of star formation efficiency), and of the ages of the oldest stars elsewhere in the Galactic disk (which can be used to determine if the dis...