Large-Scale Statistics from Line Intensity Mapping Simulations

Line Intensity Mapping (LIM), which measures the aggregate line and continuum spectrum within large conical volumes (light-cones), provides a rapid and deep probe of the evolution of galaxies, the interstellar (ISM) and intergalactic (IGM) media, though this information is subtle and encoded in a complex way. Since deep LIM surveys in a diverse set of optical, radio, and millimeter wave lines probing a wide range of physical processes are underway or will soon be, there is a great need for tools to help connect the observables to physical conditions.

The research team will combine multiple emission lines generated by semi-analytic models (SAMs) of galaxy formation with existing cosmological simulations to derive a suite of "mock" intensity maps in a self-consistent manner. By varying the SAMs the resulting simulated data sets will inform the calibration and interpretation of LIM surveys. This research will also support research activities by a postdoctoral researcher and a graduate student, as well as efforts by the principal investigator to develop astronomy/cosmology classes for area majority-minority high-schools in New York City.

The research team will use SAMs together with existing cosmological simulations to produce sets of light-cones, mock LIM maps and galaxy surveys out to z = 10 for 2-square degree survey fields in order to compute the LIM auto- and cross-power spectrum and 1-point PDF for the 21 cm HI line, various sub/millimeter wave CO transitions, 158 micron [C II] fine structure line, and Hα. They will also simulate astrophysical parameter estimates with these statistics for realistic representative surveys.

These will contain optical photometry which will be used for simulated cross-correlations with galaxy surveys such as the Dark Energy Spectroscopic Instrument (DESI). Scientific deliverables released by the team will include halo catalogs and halo merger trees, galaxy catalogs produced by SAMs, broad-band photometry and line properties for N-body snapshots, source catalogs along light-cones, and multi-wavelength LIM and synthetic cosmic infrared background maps.

The full suite of simulated survey catalogs and maps will also allow the team to determine how well these statistical measures can constrain the physical processes driving galaxy formation as well as search for synergies between LIM and traditional galaxy surveys.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.