Recent & Upcoming Talks


The dimensionally split power spectrum/two-point correlation are standard tools for constraining the cosmological model from redshift surveys. Given the Lyman-alpha emission line, I will try to motivate what significant distortions from the line’s radiative transfer modify those statistics.

Lyman-alpha based emission line surveys are prone to errors in their interpretation due to the complex radiative transfer for this line. We address this issue by running full radiative transfer simulations on the Illustris simulations and generate mock observations of Lyman-alpha emitters. Doing so, we can quantify two physical distortion effects in the two-point correlation function introduced by radiative transfer.

Lyman-alpha emitters and their intensity map are powerful probes of the large-scale structure at optical and near-infrared wavelength as HETDEX plans. However, the fact that the Lyman-alpha photons are scattered due to the neutral hydrogen has non-negligible impact on the observed distribution of Lyman-alpha photons. To study this in detail, we run a suit of radiative transfer (RT) simulations on Illustris and quantify the impact of RT on the real space galaxy clustering (Behrens, CB et al. arXiv: 1710.06171).


Lyman-alpha emitters can be used as probes of the large-scale structure at intermediate redshifts. Recent work discusses a possible distortion from radiative transfer effects of the resonant Lyman-alpha line on the observed clustering statistics, which would also affect the upcoming HETDEX survey aiming to measure the dark energy equation of state. We reassess the influence of Lyman-alpha scattering on observed emitters by running a Lyman-alpha transport simulation on the datasets from the state of the art cosmological simulations run in the Illustris Project, combining a large volume at high resolution with various baryon feedback processes. We do not find such distortion effect. The processed datasets are also useful for the study of individual Lyman-alpha emitter in their cosmological environment and use of Lyman-alpha intensity mapping. Both applications are discussed.

Dark Energy is often presented as mysterious and incomprehensible entity in our Universe while the evidence for it in Cosmology helps to understand scientists’ motivation for its concept. Slides available in German only.