Speaker
Description
The Epoch of Reionization (EoR) marks the transition from a neutral to an ionized intergalactic medium (IGM). A key method to trace the rate of this transition is Lyman Alpha (Ly𝜶) emission from galaxies. The evolution of the IGM’s HI fraction can be inferred from Ly𝜶 observations due to its resonant nature and the damping of its emission. But to understand the effect of inter-galactic HI over Ly𝜶 we must first answer: How does Ly𝜶 look right as it emerges from a galaxy?
We present a new high-resolution spectra dataset from MMT/Binospec, accompanied by NIRCam/JWST slitless spectra coverage from the FRESCO collaboration. We provide detailed Lya profile properties of 70 galaxies at the edge of the EoR (z~5-6.5) plus 200 non-emitting Lyman-Break selected sources. The addition of high-redshift H𝜶 detections allow us to cover the systemic redshift and new properties such as Ly𝜶 escape fraction and velocity offsets.
We produce an empirical model in a Bayesian framework, used to infer the probability density function of Ly𝜶 equivalent width and escape fraction, based on UV magnitude and slope. We accompany this model by probability distributions of line emission broadness as trackers of NHI and dynamical mass, as well as Lya asymmetry results allowed by our high-resolution dataset.
In this talk I will present our empirical models for emerging Lya and discuss possible correlations originating from the ISM of young galaxies, as well as the evolution of the velocity offset of Lya with halo mass, and its implications for the search of large ionized bubbles.
