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Related papers: Modelling the H Lyman lines in evolved late-type s…

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Dust is a key component of galaxies, but its properties during the earliest eras of structure formation remain elusive. Here we present a simple semi-analytic model of the dust distribution in galaxies at $z \gtrsim 5$. We calibrate the…

Astrophysics of Galaxies · Physics 2025-07-08 Roy J. Zhao , Steven R. Furlanetto

We investigate the influence of convection on the formation of molecular spectral lines in the atmospheres of late-type giants. For this purpose we use the 3D hydrodynamical CO5BOLD and classical 1D LHD stellar atmosphere codes and…

Solar and Stellar Astrophysics · Physics 2011-05-02 A. Ivanauskas , A. Kucinskas , H. -G. Ludwig , E. Caffau

Hydrogen Balmer lines are commonly used as spectroscopic effective temperature diagnostics of late-type stars. However, the absolute accuracy of classical methods that are based on one-dimensional (1D) hydrostatic model atmospheres and…

Solar and Stellar Astrophysics · Physics 2018-08-03 A. M. Amarsi , T. Nordlander , P. S. Barklem , M. Asplund , R. Collet , K. Lind

Models are presented for the Lyman alpha emission of dusty high-redshift galaxies by combining the Press-Schechter formalism with a treatment of the inhomogeneous dust distribution inside galaxies. It is found that the amount of Lyman alpha…

Astrophysics · Physics 2008-11-26 Zoltan Haiman , Marco Spaans

We investigate the role of convection in the formation of atomic and molecular lines in the atmosphere of a red giant star. For this purpose we study the formation properties of spectral lines that belong to a number of astrophysically…

Solar and Stellar Astrophysics · Physics 2013-05-16 A. Kucinskas , M. Steffen , H. -G. Ludwig , V. Dobrovolskas , A. Ivanauskas , J. Klevas , D. Prakapavicius , E. Caffau , P. Bonifacio

Spectral Energy Distribution (SED) fitting is a well-developed astrophysical tool that has recently been applied to high-redshift Lyman Alpha-emitting galaxies. If rest-frame ultraviolet through near-infrared photometry is available, it…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Eric Gawiser

As a well-established procedure for the vast majority of normal main-sequence stars, determination of atmospheric and stellar parameters turns to be a challenging process in case of magnetic chemically peculiar stars. Inhomogeneous…

Solar and Stellar Astrophysics · Physics 2015-06-12 D. Shulyak , T. Ryabchikova , O. Kochukhov

Model atmospheres of A and B stars are computed taking into account magnetic line blanketing. These calculations are based on the new stellar model atmosphere code LLModels which implements direct treatment of the opacities due to the…

Astrophysics · Physics 2009-11-10 O. Kochukhov , S. Khan , D. Shulyak

We have written a 3D radiative transfer code that computes emerging spectra and intensity maps. We derive from radiative hydrodynamic (RHD) simulations of RSG stars carried out with CO5BOLD (Freytag et al. 2002) observables expected for red…

Astrophysics · Physics 2008-02-12 A. Chiavassa , B. Plez , E. Josselin , B. Freytag

We present the results of a detailed modeling aimed to reproduce the spectral energy distribution (SED) of dust and molecular line emission of massive protostars under the hypothesis that they form via an accretion process. We model the…

Astrophysics · Physics 2007-12-17 Mayra Osorio

Various types of galaxies observed in the cosmological scales show P-Cygni type profiles in the Lyman alpha emission lines. A Monte Carlo code is developed to investigate the Lyman alpha line transfer in an optically thick and moving medium…

Astrophysics · Physics 2016-08-30 Sang-Hyeon Ahn , Hee-Won Lee

Lyman $\alpha$ (Ly$\alpha$) is now routinely used as a tool for studying high-redshift galaxies and its resonant nature means it can trace neutral hydrogen around star-forming galaxies. Integral field spectrograph measurements of…

In Paper I we present a new model for the Galactic distribution of free electrons. In this paper we describe the input data and methodology for determining the structure and parameters of the model. Tables of the input data are provided and…

Astrophysics · Physics 2007-05-23 J. M. Cordes , T. J. W. Lazio

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…

Astrophysics · Physics 2009-11-10 Tsutomu T. Takeuchi , Takako T. Ishii

We present a new model for high redshift Lyman-Alpha Emitters (LAEs) in the cosmological context which takes into account the resonant scattering of Ly-a photons through expanding gas. The GALICS semi-analytic model provides us with the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Thibault Garel , Jérémy Blaizot , Bruno Guiderdoni , Daniel Schaerer , Anne Verhamme , Matthew Hayes

Hydrogen recombination lines are one of the major diagnostics of H II region physical properties and kinematics. In the near future, the Expanded Very Large Array (EVLA) and the Atacama Large Millimeter Array (ALMA) will allow observers to…

Astrophysics of Galaxies · Physics 2012-09-04 Thomas Peters , Steven N. Longmore , Cornelis P. Dullemond

Lyman-alpha is now widely used to investigate the galaxy formation and evolution in the high redshift universe. However, without a rigorous understanding of the processes which regulate the Lya escape fraction, physical interpretations of…

Astrophysics · Physics 2008-09-15 Hakim Atek , Daniel Kunth , Matthew Hayes , Goeran Ostlin , J. Miguel Mas-Hesse , .

Photodissociation Region (PDR) models are computed over a wide range of physical conditions, from those appropriate to giant molecular clouds illuminated by the interstellar radiation field to the conditions experienced by circumstellar…

Astrophysics · Physics 2009-07-09 Michael J. Kaufman , Mark G. Wolfire , David J. Hollenbach , Michael L. Luhman

High-redshift QSO spectra show large spatial fluctuations in the Ly-alpha opacity of the intergalactic medium on surprisingly large scales at z>~5.5. We present a radiative transfer simulation of cosmic reionization driven by galaxies that…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-06 Girish Kulkarni , Laura C. Keating , Martin G. Haehnelt , Sarah E. I. Bosman , Ewald Puchwein , Jonathan Chardin , Dominique Aubert

Str\"omgren $uvby-\beta$ photometry of the stars classified as RR Lyrae stars RU Piscium, SS Piscium and TU Ursae Majoris has been used to estimate their iron abundance, temperature, gravity and absolute magnitude. The stability of the…

Astrophysics of Galaxies · Physics 2012-10-31 A. Arellano Ferro , J. H. Pena , R. Figuera Jaimes