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相关论文: The Missing Metal Problem in Galaxy Clusters: Char…

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We compare the metallicity distribution of Galactic Halo stars with 3D realizations of hierarchical galaxy formation. Outflows from dwarf galaxies enrich the intergalactic medium inhomogeneously, at a rate depending on the local galaxy…

天体物理学 · 物理学 2009-10-31 Evan Scannapieco , Tom Broadhurst

Reconstructing the Galactic evolution of lithium (Li) is the main tool used to constrain the source(s) of Li enrichment in the Galaxy. Recent results have suggested a decline in Li at supersolar metallicities, which may indicate reduced…

We investigate the spatial distribution of iron in the intra-cluster medium in a selected sample of 41 relaxed clusters in the redshift range $0.05 < z < 1.03$ using {\sl Chandra} archival data. We compute the azimuthally-averaged,…

宇宙学与河外天体物理 · 物理学 2018-08-29 Ang Liu , Paolo Tozzi , Heng Yu , Sabrina De Grandi , Stefano Ettori

We present an analysis of $UBVRI$ data from the Selected Area SA 141. By applying recalibrated methods of measuring ultraviolet excess (UVX), we approximate abundances and absolute magnitudes for 368 stars over 1.3 square degrees out to…

星系天体物理 · 物理学 2009-11-13 Michael H. Siegel , Yuksel Karatas , I. Neill Reid

Extremely metal-poor (EMP) stars are the living fossils with records of chemical enrichment history at the early epoch of galaxy formation. By the recent large observation campaigns, statistical samples of EMP stars have been obtained. This…

星系天体物理 · 物理学 2017-10-13 Gen Chiaki , Nozomu Tominaga , Takaya Nozawa

XMM-Newton observations of 19 galaxy clusters are used to measure the elemental abundances and their spatial distributions in the intracluster medium. The sample mainly consists of X-ray bright and relaxed clusters with a cD galaxy. Along…

天体物理学 · 物理学 2009-11-10 T. Tamura , J. S. Kaastra , J. W. A. Herder , J. A. M. Bleeker , J. R. Peterson

X-ray measurements find systematically lower Fe abundances in the X-ray emitting haloes pervading groups ($kT\lesssim1.7$ keV) than in clusters of galaxies. These results have been difficult to reconcile with theoretical predictions.…

The two known ``hyper-metal-poor'' (HMP) stars, HE0107-5240 and HE1327-2326, have extremely high enhancements of the light elements C, N, and O relative to Fe and appear to represent a statistically significant excess population relative to…

天体物理学 · 物理学 2011-02-11 Jason Tumlinson

We present a chemical abundance distribution study in 14 $\alpha$, odd-Z, even-Z, light, and Fe-peak elements of approximately 3200 intermediate metallicity giant stars from the APOGEE survey. The main aim of our analysis is to explore the…

星系天体物理 · 物理学 2016-03-02 Keith Hawkins , Paula Jofre , Thomas Masseron , Gerry Gilmore

We have used the Hubble Space Telescope's Advanced Camera for Surveys (ACS) to detect and measure ~5300 stars in a single intracluster field in the Virgo Cluster. By performing F606W and F814W photometry on these stars, we have determined…

We incorporate new scale-intelligent models of metal-enriched star formation (\starss) with surrogate models of primordial stellar feedback (\starnet) into the astrophysics simulation code \enzo to analyze the impact of heterogeneous metal…

星系天体物理 · 物理学 2022-10-27 Azton I. Wells , Michael L. Norman

We report for the first time on the magnitude of the intrinsic [Fe/H] spread among ten old globular clusters (GCs) of the Large Magellanic Cloud (LMC). Such spreads are merely observed in approximately five per cent of the Milky Way GCs and…

星系天体物理 · 物理学 2018-10-31 Andrés E. Piatti , Andreas Koch

We give an update on our 0Z Survey to find more extremely metal poor (EMP) stars with [Fe/H] < -3 dex through mining the database of the Hamburg/ESO Survey. We present the most extreme such stars we have found from ~1550 moderate resolution…

天体物理学 · 物理学 2009-06-23 J. G. Cohen , N. Christlieb , A. McWilliam , S. Shectman , I. Thompson

The chemical enrichment of the early Universe is a crucial element in the formation and evolution of galaxies, and Population III (PopIII) stars must play a vital role in this process. In this study, we examine metal enrichment from massive…

星系天体物理 · 物理学 2024-02-07 Devesh Nandal , John A. Regan , Tyrone E. Woods , Eoin Farrell , Sylvia Ekström , Georges Meynet

Deriving the metallicity, [Fe/H], in low-resolution spectra of carbon-enhanced metal-poor (CEMP) stars is a tedious task that, owing to the large number of line blends, often leads to uncertainties on [Fe/H] exceeding 0.25dex. The CEMP…

太阳与恒星天体物理 · 物理学 2020-02-12 D. Singh , C. J. Hansen , J. S. Byrgesen , M. Reichert , H. M. Reggiani

It is frequently debated in literature whether a "standard" Initial Mass Function (IMF) - meaning an IMF of the kind usually adopted to explain the chemical evolution in the local Solar Neighbourhood - can account for the observed metal…

天体物理学 · 物理学 2009-11-10 L. Portinari , A. Moretti , C. Chiosi , J. Sommer-Larsen

We present a detailed chemical analysis study of 16 candidate metal-poor stars, previously identified with 2dF + AAOmega, using X-Shooter spectra and the Korg 1D local thermodynamic equilibrium spectral synthesis code. We confirm the…

We measure the baryons contained in both the stellar and hot gas components for twelve galaxy clusters and groups at z~0.1 with M=1-5e14 Msun. This paper improves upon our previous work through the addition of XMM data, enabling…

宇宙学与河外天体物理 · 物理学 2015-06-17 Anthony H. Gonzalez , Suresh Sivanandam , Ann I. Zabludoff , Dennis Zaritsky

We present a chemical abundance study of three inner old halo clusters NGC 6287, NGC 6293, and NGC 6541, finding [Fe/H] = -2.01 +/- 0.05, -1.99 +/- 0.02, and -1.76 +/- 0.02, respectively, and our metallicity measurements are in good…

天体物理学 · 物理学 2009-11-07 Jae-Woo Lee , Bruce W. Carney

We aim to study the high-precision chemical abundances of metal-poor gas clouds at cosmic noon (2<z<4) and investigate the associated enrichment histories. We analyse the abundances of four newly discovered metal-poor gas clouds utilising…

星系天体物理 · 物理学 2024-11-20 Louise Welsh , Ryan Cooke , Michele Fumagalli , Max Pettini , Gwen C. Rudie
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