IR STIG PRIMA Seminar, 27 July 2026 – NASA Science

Infrared Science and Technology Interest Group

Over the next few months, our talk series will be highlighting research from PRIMA’s Working Groups, with this talk focusing on dust properties in galaxies in the nearby universe. Stay tuned as well for overview talks this fall that highlight PRIMA’s PI science in the areas of Protoplanetary Disks and the Evolution of Dust and Metals.

IR STIG about IR STIG PRIMA Seminar

Dates

27 July 2026
9:00am PT / 12:00pm ET

Far-infrared Properties of Green Pea Galaxies, the Best Local Analogues of Galaxies in the Epoch of Reionization

Speaker

Takuya Hashimoto (University of Tsukuba)

Abstract

I will present a science case proposed by our team using PRIMA/FIRESS: a systematic investigation of the far-infrared properties of Green Pea galaxies, which are among the best local analogues of galaxies in the Epoch of Reionization. ALMA observations have revealed luminous far-infrared fine-structure lines in galaxies out to redshifts of approximately 14. In particular, these galaxies often exhibit [O III] 88 μm emission that is 2-10 times more luminous than [C II] 158 μm. Simulations suggest that such elevated line ratios may reflect highly ionized gas or a low neutral-gas covering fraction, both of which could facilitate the escape of Lyman-continuum photons. However, far-infrared spectroscopy is currently available for only a small number of local Lyman-continuum emitters.

We therefore propose PRIMA/FIRESS observations of Green Pea galaxies. FIRESS can detect multiple diagnostic lines, including [N III] 57 μm, [O I] 63 μm, [O III] 52 and 88 μm, [C II] 158 μm, and OH 119 μm absorption, within a reasonable integration time. These observations will enable us to investigate the connection between Lyman-continuum escape and far-infrared line properties, constrain the electron density, ionization state, and chemical abundance of the interstellar medium, and examine multiphase gas and outflows through the combination of optical and far-infrared diagnostics. The resulting dataset will provide an important local benchmark for interpreting future observations of distant galaxies with PRIMA and next-generation radio facilities.