搜索结果: 1-15 共查到“天文学 metal”相关记录26条 . 查询时间(0.109 秒)
Astronomers discover metal-rich galaxies in early universe
宇宙 富含金属 星系
font style='font-size:12px;'>
2023/5/17
Scanning the first images of a well-known early galaxy taken by NASA’s James Webb Space Telescope (JWST), Cornell astronomers were intrigued to see a blob of light near its outer edge.
Metal enrichment of the intergalactic medium at z=3 by galactic winds
galactic winds intergalactic medium
font style='font-size:12px;'>
2014/12/26
Studies of quasar absorption lines reveal that the low-density intergalactic medium (IGM) at z ~ 3 is enriched to between 10-3 and 10-2 solar metallicity. This enrichment may have occurred in an early...
Metal enrichment of the intergalactic medium in cosmological simulations
intergalactic medium formation starburst
font style='font-size:12px;'>
2014/12/26
Observations have established that the diffuse intergalactic medium (IGM) at z ~ 3 is enriched to ~10-2.5 solar metallicity and that the hot gas in large clusters of galaxies (ICM) is enriched to - Z ...
Vibrational Instability of Metal-Poor Low-Mass Main-Sequence Stars
Vibrational Instability Metal-Poor Low-Mass Main-Sequence Stars
font style='font-size:12px;'>
2012/2/24
We find that low-degree low-order g-modes become unstable in metal-poor low-mass stars due to the $\varepsilon$-mechanism of the pp-chain. Since the outer convection zone of these stars is limited onl...
Stellar lifetime and ultraviolet properties of the old metal-rich Galactic open cluster NGC6791: a pathway to understand the UV upturn of elliptical galaxies
Stellar lifetime ultraviolet properties old metal-rich Galactic cluster NGC6791 UV upturn elliptical galaxies
font style='font-size:12px;'>
2012/2/23
The evolutionary properties of the old metal-rich Galactic open cluster NGC6791 are assessed, based on deep UB photometry and 2Mass JK data. For 4739 stars in the cluster, bolometric luminosity and ef...
Environmental Effects on the Metal Enrichment of Low Mass Galaxies in Nearby Clusters
Environmental Effects the Metal Enrichment Low Mass Galaxies Nearby Clusters
font style='font-size:12px;'>
2012/2/21
In this paper we study the chemical history of low-mass star-forming (SF) galaxies in the local Universe clusters Coma, A1367, A779, and A634. The aim of this work is to search for the imprint of the ...
Polypropylene Embedded Metal-Mesh Broadband Achromatic Half Wave Plate for Millimeter Wavelengths
Embedded Metal-Mesh Broadb Achromatic Half Wave Plate Millimeter Wavelengths
font style='font-size:12px;'>
2011/10/11
We describe a novel multi-layered metal mesh achromatic half wave plate for use in astronomical polarimetric instruments. The half wave plate is designed to operate across the frequency range from 125...
The Stellar Abundances for Galactic Archaeology (SAGA) Database II - Implications for Mixing and Nucleosynthesis in Extremely Metal-Poor Stars and Chemical Enrichment of the Galaxy
The Stellar Abundances for Galactic Archaeology Database II
font style='font-size:12px;'>
2011/1/13
We discuss the characteristics of known extremely metal-poor (EMP) stars in the Galaxy using the Stellar Abundances for Galactic Archaeology (SAGA) database (Suda et al. 2008, PASJ, 60, 1159).The anal...
The Birth of a Galaxy: Primordial Metal Enrichment and Population II Stellar Populations
cosmology methods numerical hydrodynamics radiative transfer star formation
font style='font-size:12px;'>
2010/11/15
Population III stars first form in dark matter halos with masses around 106M⊙. By definition,
they are metal-free, and their protostellar collapse is driven by molecular hydrogen cooling in the gas-p...
The HARPS search for southern extrasolar planets XXV. Results from the metal-poor sample
planets and satellites formation – Stars abundances – planetary systems – Techniques spectroscopic – Techniques
font style='font-size:12px;'>
2010/11/12
Searching for extrasolar planets around stars of different metallicity may provide strong constraints to the models of planet formation and evolution. In this paper we present the overall results of a...
A Carbon-enhanced Metal-poor Damped Lyman alpha System: Probing Gas from Population III Nucleosynthesis?
galaxies abundances − galaxies evolution − quasars absorption lines quasars: individual J0035− 0918 − stars carbon − stars
font style='font-size:12px;'>
2010/11/10
We present high resolution observations of an extremely metal-poor damped Ly system, at zabs = 2.3400972 in the spectrum of the QSO J0035−0918, exhibiting an abundance pattern consistent with mo...
The RAVE Survey: Rich in Very Metal-Poor Stars
The RAVE Survey Rich Metal-Poor Stars
font style='font-size:12px;'>
2011/1/10
Very metal-poor stars are of obvious importance for many problems in chemical evolution, star formation, and galaxy evolution. Finding complete samples of such stars which are also bright enough to al...
Asymmetric Line Profiles in Spectra of Gaseous Metal Disks Around Single White Dwarfs
Solar and Stellar Astrophysics (astro-ph.SR)
font style='font-size:12px;'>
2011/1/7
Around several single DAZ and DBZ white dwarfs metal-rich disks have been observed, which are mostly believed to originate from disruption of smaller rocky planetesimals. In some cases the material do...
Asteroseismic modelling of the metal-poor star Tau Ceti
Solar and Stellar Astrophysics (astro-ph.SR)
font style='font-size:12px;'>
2011/1/5
Asteroseismology is an effcient tool not only for testing stellar structure and evolutionary theory but also constraining the parameters of stars for which solar-like oscillations are detected, presen...
Lyman `bump' galaxies - II. A possible signature of massive extremely metal-poor or metal-free stars in z=3.1 Ly-alpha emitters
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
font style='font-size:12px;'>
2010/12/29
Deep NB359 imaging with Subaru by Iwata et al. have detected surprisingly strong Lyman continuum (LyC; ~900A in the rest-frame) from some LAEs at z=3.1. However, the redshifts might be misidentified d...