University of Pennsylvania Astronomy Seminar
LIMFAST: a Semi-numerical Tool for Line Intensity Mapping
Intensity Mapping (IM) is emerging as a promising technique to study the evolution of the universe from the Cosmic Dawn down to the present day, and this creates a pressing need for new multi-scale and multi-frequency simulation tools. LIMFAST is a simulation code designed for such a purpose focusing on the epoch of cosmic reionization (z>5). LIMFAST builds on the 21cmFAST cosmological code, and takes advantage of a semi-numerical scheme to enable multiple realizations covering different galaxy models and reionization histories over large cosmic volumes in a short time. I will present how a flexible star-formation formalism is implemented in LIMFAST, accounting for Pop II and Pop III stellar components, as well as the metal enrichment of the galactic environment. Furthermore, we have designed LIMFAST to compute the emission of over a hundred emission lines, which will enable a large number of multi-line studies at high redshift. This treatment takes into account the properties of the medium and derives the emission from tabulated results of external photoionization computations. I will discuss the details of the code and a set of initial results, as well as the variations and extensions that can be easily implemented into LIMFAST when released publicly to the community.