Lyα EMISSION FROM COSMIC STRUCTURE. I. FLUORESCENCE

Lyα Emission from Structure Formation

The nature of the interaction between galaxies and the intergalactic medium (IGM) is one of the most fundamental problems in astrophysics. The accretion of gas onto galaxies provides fuel for star formation, while galactic winds transform the nearby IGM in a number of ways. One exciting technique to study this gas is through the imaging of hydrogen Lyα emission. We use cosmological simulations ...

Mapping the Cosmic Web with Lyα Emission

We use a high-resolution cosmological simulation to predict the distribution of H I Lyα emission from the lowredshift (z . 0.5) intergalactic medium (IGM). Our simulation can be used to reliably compute the emission from optically thin regions of the IGM but not that of self-shielded gas. We therefore consider several models that bracket the expected emission from self-shielded regions. Most ga...

Broad Lyα Emission from Supernova Remnants in Young Galaxies

Context. Charge transfer (or exchange) reactions between hydrogen atoms and protons in collisionless shocks of supernova remnants (SNRs) are a natural way of producing broad Balmer, Lyman and other lines of hydrogen. Aims. We wish to quantify the importance of shock-induced, non-thermal hydrogen emission from SNRs in young galaxies. Methods. We present a method to estimate the luminosity of bro...

Fluorescent Lyα Emission from the High-redshift Intergalactic Medium

We combine a high-resolution hydro-simulation of the ΛCDM cosmology with two radiative transfer schemes (for continuum and line radiation) to predict the properties, spectra and spatial distribution of fluorescent Lyα emission at z ∼ 3. We focus on line radiation produced by recombinations in the dense intergalactic medium ionized by UV photons. In particular, we consider both a uniform backgro...

Detecting Radio Emission from Cosmic Ray