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相关论文: The missing metals problem: I. How many metals are…

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Lyman-break galaxies (LBGs) contain a non-negligible amount of dust. Takeuchi et al. (2003)(T03) constructed a model of the infrared spectral energy distribution (SED) for very young galaxies by taking into account the dust size…

天体物理学 · 物理学 2009-11-10 Tsutomu T. Takeuchi , Takako T. Ishii

We thoroughly explore the properties of (sub)-millimeter (mm) selected galaxies (SMGs) in the Shark semi-analytic model of galaxy formation. Compared to observations, the predicted number counts at wavelengths (lambda) 0.6-2mm and redshift…

Although dust content is usually assumed to depend uniquely on metallicity, recent observations of two extremely metal-poor dwarf galaxies have suggested that this may not always be true. At a similar oxygen abundance of ~ 3% Zsun, the…

星系天体物理 · 物理学 2016-02-17 Raffaella Schneider , Leslie Hunt , Rosa Valiante

Matching the number counts and redshift distribution of submillimeter galaxies (SMGs) without invoking modifications to the initial mass function (IMF) has proved challenging for semi-analytic models (SAMs) of galaxy formation. We adopt a…

星系天体物理 · 物理学 2018-06-12 Mohammadtaher Safarzadeh , Yu Lu , Christopher C. Hayward

Four recent observational results have challenged our understanding of high--redshift galaxies, as they require the presence of far more ultraviolet photons than should be emitted by normal stellar populations. First, there is significant…

天体物理学 · 物理学 2009-11-11 Raul Jimenez , Zoltan Haiman

We measure the oxygen metallicity of the ionized gas along the major axis of seven dwarf star-forming galaxies. Two of them, SDSSJ1647+21 and SDSSJ2238+14, show 0.5 dex metallicity decrements in inner regions with enhanced star-formation…

Submillimeter galaxies (SMGs) constitute a key population of bright star-forming galaxies at high redshift. These galaxies challenge galaxy formation models, particularly in reproducing their observed number counts and redshift…

Sub-mm detected galaxies located at redshifts $z > 1$ host a major fraction of the bolometric luminosity at high redshifts due to thermal emission from heated dust grains, yet the nature of these objects remains a mystery. The major problem…

天体物理学 · 物理学 2009-11-10 Christopher J. Conselice , Scott C. Chapman , Rogier A. Windhorst

Although there have been numerous studies of chemical abundances in the Galactic bulge, the central two degrees have been relatively unexplored due to the heavy and variable interstellar extinction, extreme stellar crowding, and the…

星系天体物理 · 物理学 2019-07-17 M. Schultheis , R. M. Rich , L. Origlia , N. Ryde , G. Nandakumar , B. Thorsbro , N. Neumayer

We present the first results from a survey of the relative spatial distributions of galaxies, intergalactic neutral hydrogen, and intergalactic metals at high redshift. We obtained high-resolution spectra of 8 bright QSOs at 3.1<z<4.1 and…

天体物理学 · 物理学 2009-11-07 K. L. Adelberger , C. C. Steidel , A. E. Shapley , M. Pettini

We have measured the abundances of Zn, Si, Mn, Cr, Fe, and Ni in three damped Lyman alpha systems at redshifts z < 1 from high resolution echelle spectra of QSOs recorded with the Keck I telescope. In all three cases the abundances of Cr,…

天体物理学 · 物理学 2009-10-31 Max Pettini , Sara Ellison , Charles C. Steidel , Alice E. Shapley , David V. Bowen

We use the most extensive integral field spectroscopic map of a local galaxy, NGC 628, combined with gas and stellar mass surface density maps, to study the distribution of metals in this galaxy out to 3 effective radii ($\rm R_e$). At each…

星系天体物理 · 物理学 2015-11-18 F. Belfiore , R. Maiolino , M. Bothwell

We present a simple, redshift-independent analytic model that explains the local Fundamental Metallicity Relation (FMR), taking into account the physical processes of star formation, inflow of metal-poor intergalactic medium (IGM) gas, and…

宇宙学与河外天体物理 · 物理学 2015-06-04 Pratika Dayal , Andrea Ferrara , James S. Dunlop

We investigate the evolution of the metallicity of the intergalactic medium (IGM) with particular emphasis on its spatial distribution. We propose that metal enrichment occurs as a two step process. First, supernova (SN) explosions eject…

天体物理学 · 物理学 2008-11-26 Andrea Ferrara , Max Pettini , Yuri Shchekinov

Interferometric observations have demonstrated that a significant fraction of single-dish submillimetre (submm) sources are blends of multiple submm galaxies (SMGs), but the nature of this multiplicity, i.e. whether the galaxies are…

Metal mixing plays critical roles in the enrichment of metals in galaxies. The abundance of elements such as Mg, Fe, and Ba in metal-poor stars help us understand the metal mixing in galaxies. However, the efficiency of metal mixing in…

星系天体物理 · 物理学 2017-04-12 Yutaka Hirai , Takayuki R. Saitoh

The oxygen abundances in the \HII regions of a sample of low surface brightness (LSB) disk galaxies are presented. In general, LSB galaxies are found to be metal poor ($Z < {1 \over 3} Z\solar$). Indeed, some LSB galaxies rival the lowest…

天体物理学 · 物理学 2009-10-22 Stacy McGaugh

The metallicity of strong HI systems, spanning from damped Lyman-alpha absorbers (DLAs) to Lyman-limit systems (LLSs) is explored between z = 5->0 using the EAGLE high-resolution cosmological hydrodynamic simulation of galaxy formation. The…

星系天体物理 · 物理学 2018-04-16 Alireza Rahmati , Benjamin D. Oppenheimer

The host galaxies of the five local, z<0.25, long-duration gamma-ray bursts, each of which had a well-documented associated supernova, are all faint and metal-poor compared to the population of local star-forming galaxies. We quantify this…

Observations of metal lines in $\lyal$ absorption systems of small H~I column density and their ubiquitous nature suggest that the intergalactic medium (IGM) was enriched to about $Z \sim 0.01 \> Z_{\odot}$ by a redshift $z \sim 3$. We…

天体物理学 · 物理学 2015-06-24 Biman Nath , Neil Trentham
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