Polycyclic aromatic hydrocarbons in the high-redshift universe: prospect of the PRIMA FIRESS low-resolution spectroscopy

July 2025 • 2025JATIS..11c1634Y

Authors • Yoon, Ilsang • Hensley, Brandon • Lai, Thomas S.-Y. • Shivaei, Irene • García-Bernete, Ismael • Donnelly, Grant P. • Pope, Alexandra • Smith, John-David T. • Torrey, Paul

Abstract • The integrated luminosity from the features of the polycyclic aromatic hydrocarbons (PAHs) exceeds the luminosity from atomic and molecular emission lines in the star-forming regions in galaxies and is a potential tracer of galaxy-scale star formation and molecular gas content of the high-redshift universe. We simulate the observable PAH spectra using the PRobe far-Infrared Mission for Astrophysics far-infrared enhanced survey spectrometer (FIRESS) and investigate the capability of the FIRESS low-resolution spectroscopy for observing PAH emission spectrum from high-redshift galaxies. Our investigation suggests that (1) PRIMA observations of PAH emission are ≳10 times more efficient at detecting galaxies than the VLA observations of CO(1-0) for galaxies with the same infrared luminosity, (2) PRIMA/FIRESS can detect the PAH emission from galaxies with L_IR∼10¹²L_⊙ up to the end of reionization (and possibly beyond, if L_IR∼10¹³L_⊙), (3) the PAH band ratios measured from a full spectral fitting and from a simple flux "clipping" method are different and vary depending on the interstellar radiation field strength, and (4) PRIMA/FIRESS can also be used as the PAH mapping instrument to measure star formation and redshift of the galaxies in high-redshift protoclusters.

Links

• PREPRINT http://arxiv.org/abs/2509.02470
• ELECTR https://doi.org/10.1117%2F1.JATIS.11.3.031634