Cosmology Constraints from Type Ia Supernova Simulations of the Nancy Grace Roman Space Telescope Strategy Recommended by the High Latitude Time Domain Survey Definition Committee

TL;DR

This study simulates the Nancy Grace Roman Space Telescope's supernova survey to forecast its potential for constraining dark energy parameters, showing significant improvements over current constraints.

Contribution

It provides a detailed simulation and analysis pipeline for Roman supernova data, estimating dark energy constraints including systematic uncertainties.

Findings

10,000 Roman SNe Ia simulated for dark energy analysis

Combined Roman and LSST data yield high figure of merit

Predicted constraints surpass NASA requirements

Abstract

Within the next few years, the upcoming Nancy Grace Roman Space Telescope will be gathering data for the High Latitude Time Domain Survey (HLTDS) that will be used to significantly improve the Type Ia supernova measurement of the dark energy equation of state parameters w0 and wa. Here we generate a catalog-level simulation of the in-guide strategy recommended by the HLTDS definition committee, and determine dark energy parameter constraints using a detailed analysis that includes light curve fitting, photometric redshifts and classification, BEAMS formalism, systematic uncertainties, and cosmology fitting. After analysis and selection requirements, the sample includes 10,000 Roman SNe Ia that we combine with 4,400 events from LSST. The resulting dark energy figure of merit is well above the NASA mission requirement of 326, with the caveat that SN Ia model training systematics have not been included.