Abstract
Abstract
During reionization, a fraction of galactic Lyα emission is scattered in the intergalactic medium (IGM) and appears as diffuse light extending megaparsecs from the source. We investigate how to probe the properties of the early galaxies and their surrounding IGM using this scattered light. We create a Monte Carlo algorithm to track individual photons and reproduce several test cases from previous literature. Then, we run our code on the simulated IGM of the CoDaII simulation. We find that the scattered light can leave an observable imprint on the emergent spectrum if collected over several square arcminutes. Scattering can redden the emission by increasing the path lengths of photons, but it can also make the photons bluer by upscattering them according to the peculiar motion of the scatterer. The photons emitted on the far blue side of the resonance appear more extended in both frequency and space compared to those emitted near the resonance. This provides a discriminating feature for the blueward emission, which cannot be constrained from the unscattered light coming directly from the source. The ionization state of the IGM also affects the scattered light spectrum. When the source is in a small H ii region, the emission goes through more scatterings in the surrounding H i region regardless of the initial frequency and ends up more redshifted and spatially extended. This can result in a weakening of the scattered light toward high z during reionization. Our results provide a framework for interpreting the scattered light to be measured by high-z integral-field-unit surveys.
Funder
MEXT ∣ Japan Society for the Promotion of Science
National Research Foundation of Korea
National Science Foundation
National Aeronautics and Space Administration
NASA ∣ Jet Propulsion Laboratory
French Agence Nationale de la Recherche
UKRI ∣ Science and Technology Facilities Council
NSF XSEDE
Publisher
American Astronomical Society
Subject
Space and Planetary Science,Astronomy and Astrophysics
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献