中文
相关论文

相关论文: Modelling the H Lyman lines in evolved late-type s…

200 篇论文

The high-redshift (z>2) galaxies discovered over the last few years with the Lyman-break technique represent, in number density, a major fraction of the galaxies known in the Local Universe. Thus, understanding the properties and the nature…

天体物理学 · 物理学 2007-05-23 Daniela Calzetti

Damped Lyman-alpha systems (DLAs) are useful probes of star formation and galaxy formation at high redshift. We study the physical properties of DLAs and their relationship to Lyman-break galaxies using cosmological hydrodynamic simulations…

天体物理学 · 物理学 2008-11-26 Kentaro Nagamine

We present a sample of 33 spectroscopically confirmed z ~ 3.1 Ly$\alpha$-emitting galaxies (LAEs) in the Cosmological Evolution Survey (COSMOS) field. This paper details the narrow-band survey we conducted to detect the LAE sample, the…

[Abridged] The detection of the rotational lines of CO in proto-galaxies in the early Universe provides one of the most promising ways of probing the fundamental physical properties of a galaxy, such as its size, dynamical mass, gas…

天体物理学 · 物理学 2009-11-11 T. R. Greve , J. Sommer-Larsen

The spectral data on the diffuse Galactic gamma-rays, at medium and high latitudes (|b| > 10) and energies of 1-100 GeV, recently published by the Fermi Collaboration are used to produce a novel study on the gamma-ray emissivity in the…

高能天体物理现象 · 物理学 2011-10-28 Maryam Tavakoli , Ilias Cholis , Carmelo Evoli , Piero Ullio

The Hydrogen Lyman-alpha (Lya) line shows a large variety of shapes which is caused by factors at different scales, from the interstellar medium to the intergalactic medium. This work aims to provide a systematic inventory and…

Calculating abundance stratifications in ApBp/HgMn star atmospheres, we are considering mass-loss in addition to atomic diffusion in our numerical code in order to achieve more realistic models. These numerical simulations with mass-loss…

太阳与恒星天体物理 · 物理学 2018-11-28 G. Alecian , M. J. Stift

In the last few years we have developed stellar model atmospheres which included effects of anomalous abundances and strong magnetic field. The full treatment of anomalous Zeeman splitting and polarized radiative transfer were introduced in…

天体物理学 · 物理学 2015-05-13 Denis Shulyak , Oleg Kochukhov , Sergiy Khan

Spectra of late-type stars are usually analyzed with static model atmospheres in local thermodynamic equilibrium (LTE) and a homogeneous plane-parallel or spherically symmetric geometry. The energy balance requires particular attention, as…

天体物理学 · 物理学 2009-11-06 Carlos Allende Prieto , Paul S. Barklem , Martin Asplund , Basilio Ruiz Cobo

Although observational data unequivocally point out to the presence of chromospheres in red giant stars, no attempts have been made so far to model them using 3D hydrodynamical model atmospheres. We therefore compute an exploratory 3D…

太阳与恒星天体物理 · 物理学 2017-10-04 Sven Wedemeyer , Arunas Kucinskas , Jonas Klevas , Hans-Gunter Ludwig

We investigated the properties of the late-type stellar component in the RASS at high-galactic latitude |b| based on an optically identified sample of ROSAT All-Sky Survey (RASS) X-ray sources. The stellar sample comprises ~250 objects in…

天体物理学 · 物理学 2007-05-23 F. -J. Zickgraf , J. M. Alcala , E. Covino , J. Krautter , I. Appenzeller , S. Frink , M. F. Sterzik

We conduct a comprehensive theoretical and numerical investigation of the pollution of pristine gas in turbulent flows, designed to provide new tools for modeling the evolution of the first generation of stars. The properties of such…

星系天体物理 · 物理学 2015-06-16 Liubin Pan , Evan Scannapieco , John Scalo

We present a new analytical model for the attenuation to Epoch of Reionization (EoR) galaxies by proximate neutral hydrogen gas. Many galaxy spectra in the EoR taken by JWST have shown a flux deficit at wavelengths just redward of the Lyman…

The atmospheric structure of chemically peculiar stars deviates from that of normal stars with similar fundamental parameters due to unusual chemistry, abundance inhomogeneities and the presence of strong magnetic field. These effects are…

天体物理学 · 物理学 2007-12-03 O. Kochukhov , D. Shulyak

Gas flows in and out of galaxies through their circumgalactic medium (CGM) are poorly constrained and direct observations of this faint, diffuse medium remain challenging. We use a sample of five $z$ $\sim$ 1-2 galaxy counterparts to Damped…

We present theoretical calculations of the quasi-molecular line profiles for the Lyman (Lya, Lyb, Lyg, Lyd) and Balmer (Ha, Hb, Hg, Hd, He, H8, H9, and H10) series, perturbed by collisions with protons. In all calculations we include the…

太阳与恒星天体物理 · 物理学 2015-06-04 M. G. Santos , S. O. Kepler

We present new calculations of unified line profiles for hydrogen perturbed by collisions with protons. We report on new calculations of the potential energies and dipole moments which allow the evaluation of profiles for the lines of the…

太阳与恒星天体物理 · 物理学 2015-06-23 Ingrid Pelisoli , M. G. Santos , S. O. Kepler

We examine the dust geometry and Ly{\alpha} scattering in the galaxies of the Lyman Alpha Reference Sample (LARS), a set of 14 nearby (0.02 < $z$ < 0.2) Ly{\alpha} emitting and starbursting systems with Hubble Space Telescope Ly{\alpha},…

We build a physical model for high-redshift Lyman Alpha emitters (LAEs) by coupling state of the art cosmological simulations (GADGET-2) with a dust model and a radiative transfer code (pCRASH). We post-process the cosmological simulation…

宇宙学与河外天体物理 · 物理学 2014-05-07 A. Hutter , P. Dayal , A. M. Partl , V. Müller

We employ observationally determined intrinsic velocity widths and column densities of damped Lyman-alpha systems at high redshift to investigate the distribution of baryons in protogalaxies within the context of a standard cold dark matter…

天体物理学 · 物理学 2009-10-30 Karsten Jedamzik , Jason X. Prochaska