Probing Individual Star Forming Regions Within Strongly Lensed Galaxies at z > 1

TL;DR

This study uses gravitational lensing to resolve and analyze individual star forming regions in distant galaxies, revealing diverse properties and complex star formation processes during the universe's peak star formation era.

Contribution

It demonstrates the use of strong gravitational lensing combined with multi-wavelength spectroscopy to study sub-galactic star forming regions at high redshift, providing new insights into their properties.

Findings

Wide variation in UV spectral features among regions

Significant differences in Lyman-alpha and P Cygni line strengths

Evidence of diverse outflow and nebular gas properties

Abstract

Star formation occurs on physical scales corresponding to individual star forming regions, typically of order ~100 parsecs in size, but current observational facilities cannot resolve these scales within field galaxies beyond the local universe. However, the magnification from strong gravitational lensing allows us to measure the properties of these discrete star forming regions within galaxies in the distant universe. New results from multi-wavelength spectroscopic studies of a sample of extremely bright, highly magnified lensed galaxies are revealing the complexity of star formation on sub-galaxy scales during the era of peak star formation in the universe. We find a wide range of properties in the rest-frame UV spectra of individual galaxies, as well as in spectra that originate from different star forming regions within the same galaxy. Large variations in the strengths and velocity structure of Lyman-alpha and strong P Cygni lines such as C IV, and MgII provide new insights into the astrophysical relationships between extremely massive stars, the elemental abundances and physical properties of the nebular gas those stars ionize, and the galactic-scale outflows they power.