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Within collapsing protogalaxies, thermal instability leads to the formation of a population of cool fragments which are confined by the pressure of a residual hot background medium. The critical mass required for the cold clouds to become…

天体物理学 · 物理学 2007-05-23 Uffe Hellsten , D. N. C. Lin

We present the analysis of deep X-ray observations of 10 massive galaxy clusters at redshifts $1.05 < z < 1.71$, with the primary goal of measuring the metallicity of the intracluster medium (ICM) at intermediate radii, to better constrain…

We present a sample of 34 weak metal line absorbers at $z< 0.3$ complied via the simultaneous detections ($3\sigma$) of the SiII$\lambda1260$ and CII$\lambda1334$ absorption lines, with $W_{r}$(SiII)$<0.2$ \AA\ and $W_{r}$(CII)$<0.3$ \AA,…

We investigate archaeologically how the metallicity in both stellar and gaseous components of spiral galaxies of differing masses evolve with time, using data from the SDSS-IV MaNGA survey. For the stellar component, we can measure this…

Because the same massive stars that reionized the intergalactic medium (IGM) inevitably exploded as supernovae that polluted the Universe with metals, the history of cosmic reionization and enrichment are intimately intertwined. While the…

宇宙学与河外天体物理 · 物理学 2021-07-14 Joseph F. Hennawi , Frederick B. Davies , Feige Wang , Jose Oñorbe

We study the evolution of the stellar component and the metallicity of both the intracluster medium and of stars in massive ($M_{\rm vir}\approx 6\times 10^{14}$ M$_{\odot}/h$) simulated galaxy clusters from the Rhapsody-G suite in detail…

星系天体物理 · 物理学 2016-04-27 Davide Martizzi , Oliver Hahn , Hao-Yi Wu , August E. Evrard , Romain Teyssier , Risa H. Wechsler

At redshifts z_abs < 2, quasar absorption-line constraints on space-time variations in the fine-structure constant, alpha, rely on the comparison of MgII and FeII transition wavelengths. One potentially important uncertainty is the relative…

天体物理学 · 物理学 2008-11-26 Y. Fenner , M. T. Murphy , B. K. Gibson

We investigate the extent and the properties of the MgII cool, low-density absorbing gas located in the halo and in the circum-galactic environment of quasars, using a sample of 31 projected quasar pairs with impact parameter pd<200kpc in…

宇宙学与河外天体物理 · 物理学 2015-06-19 E. P. Farina , R. Falomo , R. Scarpa , R. Decarli , A. Treves , J. K. Kotilainen

I review our recent results concerning the metal abundances in quasar absorption-line spectra obtained with the UVES/VLT, HIRES/ KECK, and STIS/HST spectrographs. The analysis is based on the Monte Carlo inversion procedure aimed at the…

天体物理学 · 物理学 2007-05-23 S. A. Levshakov

We present the mass-metallicity (MZ) and luminosity-metallicity (LZ) relations at z ~ 0.8 from ~1350 galaxies in the Deep Extragalactic Evolutionary Probe 2 (DEEP2) survey. We determine stellar masses by fitting the spectral energy…

宇宙学与河外天体物理 · 物理学 2015-05-19 H. J. Zahid , L. J. Kewley , F. Bresolin

We measure a relation between the depth of four prominent rest-UV absorption complexes and metallicity for local galaxies and verify it up to z~3. We then apply this relation to a sample of 224 galaxies at 3.5 < z < 6.0 (<z> = 4.8) in…

Understanding the spatial distribution of metals within galaxies allows us to study the processes of chemical enrichment and mixing in the interstellar medium (ISM). In this work, we map the two-dimensional distribution of metals using a…

Galactic chemical evolution models which include sodium from type II supernovae alone underestimate the abundance of sodium in the interstellar medium by a factor of two to three over about 3 dex in metallicity and predict a flat behaviour…

天体物理学 · 物理学 2007-05-23 Robert G. Izzard , Brad K. Gibson , Richard J. Stancliffe

We present a statistical analysis of the photometric properties and spatial distribution of more than 2,800 MgII absorbers with 0.37<z<1 and rest equivalent width W_0(\lambda2796)>0.8\AA detected in SDSS quasar spectra. Using an improved…

Ca II triplet spectroscopy has been used to derive stellar metallicities for individual stars in four LMC fields situated at galactocentric distances of 3\arcdeg, 5\arcdeg, 6\arcdeg\@ and 8\arcdeg\@ to the north of the Bar. Observed…

天体物理学 · 物理学 2009-11-13 Ricardo Carrera , Carme Gallart , Eduardo Hardy , Antonio Aparicio , Robert Zinn

Understanding the chemical enrichment of different elements is crucial to gaining a complete picture of galaxy chemical evolution. In this study, we present a new sample of 46 low-redshift, low-mass star-forming galaxies at $M_*\sim…

We measured $^{35}$Cl abundances in 52 M giants with metallicities between -0.5 $<$ [Fe/H] $<$ 0.12. Abundances and atmospheric parameters were derived using infrared spectra from CSHELL on the IRTF and from optical echelle spectra. We…

太阳与恒星天体物理 · 物理学 2021-03-16 Z. G. Maas , C. A. Pilachowski

Observations and modeling suggest that the dust abundance (gas-to-dust ratio, G/D) depends on (surface) density. The variations of the G/D provide constraints on the timescales for the different processes involved in the lifecycle of metals…

星系天体物理 · 物理学 2017-05-31 Julia Roman-Duval , Caroline Bot , Jeremy Chastenet , Karl Gordon

The evolution of the cosmic dust content and the cycle between metals and dust in the interstellar medium (ISM) play a fundamental role in galaxy evolution. The chemical enrichment of the Universe can be traced through the evolution of the…

We present numerical simulations to describe the nucleosynthesis and evolution of pre-Galactic clouds in a model which is motivated by cold dark matter simulations of hierarchical galaxy formation. We adopt a SN-induced star-formation…

天体物理学 · 物理学 2007-05-23 L. Saleh , T. C. Beers , G. J. Mathews
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