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相关论文: ALPACA: A New Semi-Analytic Model for Metal Absorp…

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We used our database of ESO VLT-UVES spectra of quasars to build up a sample of 67 Damped Lyman-alpha (DLA) systems with redshifts 1.7<zabs<3.7. For each system, we measured average metallicities relative to Solar, [X/H] (with either X=Zn,…

天体物理学 · 物理学 2009-11-11 C. Ledoux , P. Petitjean , P. Moller , J. Fynbo , R. Srianand

Starting from the SFR per unit physical area, determined for DLAs using the C II* method, we obtain the SFR per unit comoving volume at $z$ $\approx$ 3, and find that it agrees with that for the Lyman Break Galaxies (LBGs). Though the mass…

天体物理学 · 物理学 2008-11-26 Arthur M. Wolfe , Eric Gawiser , Jason X. Prochaska

We consider the sensitivity of the circular-orbit adiabatic contraction approximation to the baryon condensation rate and the orbital structure of dark matter halos in the $\Lambda$CDM paradigm. Using one-dimensional hydrodynamic…

天体物理学 · 物理学 2008-11-26 Jun-Hwan Choi , Yu Lu , H. J. Mo , Martin D. Weinberg

We present a statistical analysis of the properties of a large sample of dynamically hot old stellar systems, from globular clusters to giant ellipticals, which was performed in order to investigate the origin of ultra-compact dwarf…

宇宙学与河外天体物理 · 物理学 2015-06-04 Tanuka Chattopadhyay , Margarita Sharina , Emmanuel Davoust , Tuli De , Asis Kumar Chattopadhyay

We searched for 21-cm absorption associated with the z_abs = 1.3647 absorption system toward PKS 0237-233 using the GMRT. A high quality UVES spectrum shows that C I and C I* are detected at this redshift together with C II*, Mg I, Mg II,…

天体物理学 · 物理学 2008-11-26 Raghunathan Srianand , Neeraj Gupta , Patrick Petitjean

We present ALMA observations of 30 Doradus -- the highest resolution view of molecular gas in an extragalactic star formation region to date (~0.4pc x 0.6pc). The 30Dor-10 cloud north of R136 was mapped in 12CO 2-1, 13CO 2-1, C18O 2-1,…

The kinematics of damped Lyman alpha absorbers (DLAs) are difficult to reproduce in hierarchical galaxy formation models, particularly the preponderance of wide systems. We investigate DLA kinematics at z=3 using high-resolution…

宇宙学与河外天体物理 · 物理学 2010-08-30 Sungryong Hong , Neal Katz , Romeel Davé , Mark Fardal , Dušan Kereš , Benjamin D. Oppenheimer

Using STIS and VLT UVES observations we have examined the ionization, abundances, and differential dust depletion of metals, the kinematic structure, and the physical conditions in the molecular hydrogen-bearing sub-damped Ly alpha system…

天体物理学 · 物理学 2009-11-13 R. Quast , D. Reimers , R. Baade

In the framework of the Herschel/PRISMAS Guaranteed Time Key Program, the line of sight to the distant ultracompact HII region W51e2 has been observed using several selected molecular species. Most of the detected absorption features are…

We study the absorption of a minimally coupled scalar in the gravitational background created by a stack of near-extremal black three-branes, and more generally by M2, M5 and Dp branes. The absorption probability has the form P(l) = P_0(l)…

高能物理 - 理论 · 物理学 2009-11-07 G. Policastro , A. Starinets

We report observations from the Hubble Space Telescope (HST) and the VLA on the galactic environment, metallicity, and D/H in strong low-redshift Lya absorption systems toward the bright BL Lac object PKS 2155-304. GHRS/G160M spectra at 20…

Using the GAEA semi-analytic model, we analyse the connection between Damped Lyman-$\alpha$ systems (DLAs) and HI in galaxies. Our state-of-the-art semi-analytic model is tuned to reproduce the local galaxy HI mass function, and that also…

星系天体物理 · 物理学 2020-08-12 Serafina Di Gioia , Stefano Cristiani , Gabriella De Lucia , Lizhi Xie

The detection and parametrization of molecular clumps is the first step in studying them. We propose a method based on Local Density Clustering algorithm while physical parameters of those clumps are measured using the Multiple Gaussian…

天体物理仪器与方法 · 物理学 2022-02-02 Xiaoyu Luo , Sheng Zheng , Yao Huang , Shuguang Zeng , Xiangyun Zeng , Zhibo Jiang , Zhiwei Chen

In this paper, we investigate the dynamics of clumps embedded in and confined by the advection-dominated accretion flows (ADAF), in which collisions among the clumps are neglected. We start from the collisionless Boltzmann equation and…

宇宙学与河外天体物理 · 物理学 2015-06-04 J. -M. Wang , C. Cheng , Y. -R. Li

We present the ancillary data and basic physical measurements for the galaxies in the ALMA Large Program to Investigate C+ at Early Times (ALPINE) survey - the first large multi-wavelength survey which aims at characterizing the gas and…

We present the detection of [OIII] emission lines from the galaxies responsible for two high-redshift z>1.75 damped Lyman-alpha (DLA) absorption lines. These are the first detections of rest-frame optical emission lines from high-redshift…

天体物理学 · 物理学 2011-03-10 S. J. Weatherley , S. J. Warren , P. Moller , S. M. Fall , J. U. Fynbo , S. M. Croom

Giant star-forming regions (clumps) are widespread features of galaxies at $z \approx 1-4$. Theory predicts that they can play a crucial role in galaxy evolution if they survive to stellar feedback for > 50 Myr. Numerical simulations show…

This study focuses on some of the most metal-poor damped Lyman alpha absorbers known in the spectra of high redshift QSOs, using new and archival observations obtained with UV-sensitive echelle spectrographs on the Keck and VLT telescopes.…

天体物理学 · 物理学 2009-11-13 Max Pettini , Berkeley J. Zych , Charles C. Steidel , Fred H. Chaffee

We present an investigation into the absorber in front of the z=2.63 radio galaxy MRC 2025-218, using integral field spectroscopy obtained at the Very Large Telescope, and long slit spectroscopy obtained at the Keck II telescope. The…

Significant fraction of matter in supercritical (or super-Eddington) accretion flow is blown away by radiation force, thus forming outflows, however, the properties of such radiation-driven outflows have been poorly understood. We have…

高能天体物理现象 · 物理学 2015-06-15 S. Takeuchi , K. Ohsuga , S. Mineshige