搜索结果: 1-15 共查到“天体物理学 metallicity”相关记录18条 . 查询时间(0.008 秒)
The Age-Metallicity Relation in the Thin Disk of the Galaxy
metallicity relation thin disk of the Galaxy
2011/9/30
HST trigonometric distances, photometric metallicities, isochronic ages from the second revised version of the Geneva--Copenhagen survey, and uniform spectroscopic Fe and Mg abundances from our master...
Anisotropic AGN Outflows and Enrichment of the Intergalactic Medium. II. Metallicity
cosmology — galaxies active — galaxies jets — intergalactic medium — methods
2010/11/15
We investigate the large-scale influence of outflows from AGNs in enriching the IGM with metals in a cosmological context. We combine cosmological simulations of large-scale structure formation with a...
The metallicity of gamma-ray burst environments from high energy observations
Gamma-ray burst general – Gamma-ray burst individual GRB050904 – early Universe – dark ages
2010/11/10
Context. Gamma-ray bursts (GRBs) and their early afterglows ionise their circumburst material. Only high-energy spectroscopy therefore, allows examination of the matter close to the burst itself. Soft...
Dust at sub-solar metallicity: the case of post-AGB stars in the Large Magellanic Cloud
Dust at sub-solar metallicity Large Magellanic Cloud
2010/11/11
Low- and intermediate-mass stars are one of the important dust sources in the interstellar medium (ISM) of galaxies. The compositions of dust ejected from these stars are likely to affect those in the...
Ice chemistry in massive Young Stellar Objects: the role of metallicity
astrochemistry – circumstellar matter – galaxies individual (LMC, SMC) –Magellanic Clouds – stars formation – stars: protostars
2010/11/15
We present the comparison of the three most important ice constituents (water, CO and CO2)
in the envelopes of massive Young Stellar Objects (YSOs), in environments of differentmetallicities:the Gala...
What happened to the other Mohicans? Realistic models of metallicity dilution by fingering convection and observational implications
hydrodynamics instabilities turbulence planets and satellites
2010/11/16
When a planet falls onto the surface of its host star, the added high-metallicity material does not remain in the surface layers, as often assumed, but is diluted into the interior through fingering (...
Metallicity appears to be one the most important tool to study the formation and evolution of galaxies. Recently, we have shown that metallicity of local galaxies is tightly related not only to stella...
Deep CO Observations and the CO-to-H_2 Conversion Factor in DDO 154, a Low Metallicity Dwarf Irregular Galaxy
galaxies ISM — ISM molecules — stars formation
2010/11/16
We present a deep spectroscopic search for CO emission in the dwarf irregular galaxy DDO154, which has an Oxygen abundance of only 1/20 the solar value. The observations were conducted in order to con...
Old open clusters and the Galactic metallicity gradient: Berkeley 20, Berkeley 66, and Tombaugh 2
Galaxy disc – Hertzsprung-Russell (HR) diagram – open clusters and associations
2010/11/15
To study the crucial range of Galactocentric distances between 12 and 16 kpc, where little
information is available, we have obtained V I CCD imaging of Berkeley 20 and BV I CCD
imaging of Berkeley ...
The WFC3 Galactic Bulge Treasury Program: Metallicity Estimates for the Stellar Population and Exoplanet Hosts
Galaxy bulge — Galaxy formation — Galaxy stellar content — stars
2010/11/10
We present new UV-to-IR stellar photometry of four low-extinction windows in the Galactic bulge, obtained with the Wide Field Camera 3 on the Hubble Space Telescope (HST). Using our five bandpasses, w...
Evolution of massive Be and Oe stars at low metallicity towards the Long Gamma Ray bursts\footnote{Based on ESO runs 069.D-0275(A), 072.D-0245(A) and (C).}
Solar and Stellar Astrophysics (astro-ph.SR)
2011/1/6
Several studies have shown recently that at low metallicity B-type stars rotate faster than in environments of high metallicity. This is a typical case in the SMC. As a consequence, it is expected tha...
Massive Oe/Be stars at low metallicity: Candidate progenitors of long GRBs?
Solar and Stellar Astrophysics (astro-ph.SR)
2011/1/6
At low metallicity the B-type stars rotate faster than at higher metallicity, typically in the SMC. As a consequence, it was expected a larger number of fast rotators in the SMC than in the Galaxy, in...
Short Lifetime of Protoplanetary Disks in Low-metallicity Environments
Solar and Stellar Astrophysics (astro-ph.SR)
2010/12/28
We studied near-infrared disk fractions of six young clusters in the low-metallicity environments with [O/H$] \sim -0.7$ using deep $JHK$ images with Subaru 8.2\,m telescope.
Measurement of a Metallicity Gradient in a z=2 Galaxy: Implications for Inside-Out Assembly Histories
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/27
We present near-infrared imaging spectroscopy of the strongly-lensed z=2.00 galaxy SDSS J120601.69+514227.8 (`the Clone arc'). Using OSIRIS on the Keck 2 telescope with laser guide star adaptive optic...
Radial Velocity and Metallicity of the Globular Cluster IC4499 Obtained with AAOmega
Galaxy Astrophysics (astro-ph.GA)
2010/12/23
We present radial velocity and metallicity measurements for the far-southern Galactic globular cluster IC4499. We selected several hundred target red giant stars in and around the cluster from the 2MA...