Strongly lensed [O III] emitters at Cosmic Noon with Roman: Characterizing extreme emission line galaxies on star cluster complex scales (100 pc)

TL;DR

This paper discusses how Roman's upcoming survey will identify and analyze strongly lensed extreme emission line galaxies at Cosmic Noon, enabling detailed study of their small-scale interstellar medium and stellar properties relevant to cosmic reionization.

Contribution

It highlights Roman's unique capability to detect and characterize lensed [O III] emitters at high redshift on small scales, advancing understanding of massive stars and the ISM during cosmic reionization.

Findings

Roman will find numerous strongly lensed [O III] emitters at 1<z<2.8.

Roman's imaging and spectroscopy will confirm lens systems and analyze their small-scale properties.

Synergistic follow-up will provide multi-wavelength insights into galaxy properties.

Abstract

Extreme emission line galaxies (EELGs) are considered the primary contributor to cosmic reionization and are valuable laboratories to study the astrophysics of massive stars. It is strongly expected that Roman's High Latitude Wide Area Survey (HLWAS) will find many strongly gravitationally lensed [O III] emitters at Cosmic Noon (1 < z < 2.8). Roman imaging and grism spectroscopy alone will simultaneously confirm these strong lens systems and probe their interstellar medium (ISM) and stellar properties on small scales ($\lesssim$ 100 pc). Moreover, these observations will synergize with ground-based and space-based follow-up observations of the discovered lensed [O III] emitters in multi-wavelength analyses of their properties (e.g., massive stars and possible escape of ionizing radiation), spatially resolved on the scales of individual star cluster complexes. Only Roman can uniquely sample a large number of lensed [O III] emitters to study the small scale (~ 100 pc) ISM and stellar properties of these extreme emission line galaxies, detailing the key physics of massive stars and the ISM that govern cosmic reionization.