arXiv: Astrophysics
Read

3D Lyman-alpha radiation transfer. III. Constraints on gas and stellar properties of z~3 Lyman break galaxies (LBG) and implications for high-z LBGs and Lyman-alpha emitters(LAEs)

Publication Date May 23, 2008

Abstract

The Aim of our study is to understand the variety of observed Lyman-alpha (Lya) line profiles and strengths in Lyman Break Galaxies (LBGs) and Lya emitters (LAEs), the physical parameters governing them, and hence deriving constraints on the gas and dust content and stellar populations of these objects. Using our 3D Lya radiation transfer code including gas and dust (Verhamme et al. 2006), we fit 11 LBGs from the FORS Deep Field with redshifts between 2.8 and 5 observed by Tapken et al. (2007). A simple geometry of a spherically expanding shell of HI is adopted. RESULTS : The variety of observed Lya profiles is successfully reproduced. Most objects show outflow velocities of 150-200 km/s; two objects are most likely quasi-static. The radial HI column density ranges from NH=2.10^{19} to 7.10^{20} cm^{-2}. Our Lya profile fits yield values of E(B-V)~0.05-0.2 for the gas extinction. We find indications for a dust-to-gas ratio higher than the Galactic value, and for a substantial scatter. The escape fraction of Lya photons is found to be determined primarily by the extinction, and a simple fit formula is proposed. Intrinsic EW(Lya)~50-100 Angstroms are found for 8/11 objects, as expected for stellar populations forming constantly over long periods (> 10-100 Myr). In three cases we found indications for younger populations. Correlations between the observed EW(Lya) and other observables such as FWHM(Lya), E(B-V),SFR(UV) etc, are reproduced. We also show that there is a clear overlap between LBGs and LAEs. Radiation transfer a...

Concepts
Powered ByUnsilo

Lyman Break Galaxies
FORS Deep Field
Lyman-alpha
Strong Lya Emission
HI Column Density
Radial HI
Lya Profile
Stellar Populations
Observables
Dust

Introducing Weekly Round-ups!Beta

Powered by R DiscoveryR Discovery

Round-ups are the summaries of handpicked papers around trending topics published every week. These would enable you to scan through a collection of papers and decide if the paper is relevant to you before actually investing time into reading it.

Climate change Research Articles published between Jun 20, 2022 to Jun 26, 2022

R DiscoveryJun 27, 2022
R DiscoveryArticles Included:  2

One eighth of the bird species in the world is considered globally threatened; the avifauna of Iraq comprises 409 species and is considered as the maj...

Read More

Coronavirus Pandemic

You can also read COVID related content on R COVID-19

R ProductsCOVID-19

ONE PROBLEM . ONE PURPOSE . ONE PLACE

Creating the world’s largest AI-driven & human-curated collection of research, news, expert recommendations and educational resources on COVID-19

COVID-19 Dashboard