We present Herschel-PACS spectroscopy of four main-sequence star-forming galaxies at z~1.5. We detect [OI]63micron line emission in BzK-21000 at z=1.5213, and measure a line luminosity, L([OI]63micron) = (3.9+/-0.7)x1.E+9 Lsun. Our PDR modelling of the interstellar medium in BzK-21000 suggests a UV radiation field strength, G~320 G0, and gas density, n~1800 cm-3, consistent with previous LVG modelling of the molecular CO line excitation. The other three targets in our sample are individually undetected in these data, and we perform a spectral stacking analysis which yields a detection of their average emission and an [OI]63micron line luminosity, L([OI]63micron) =(1.1+/-0.2)x1E+9 Lsun. We find that the implied luminosity ratio, L([OI]63micron)/L(IR), of the undetected BzK-selected star-forming galaxies broadly agrees with that of low-redshift star-forming galaxies, while BzK-21000 has a similar ratio to that of a dusty star-forming galaxy at z~6. The high [OI]63micron line luminosities observed in BzK-21000 and the z∼1−3 dusty and submm luminous star-forming galaxies may be associated with extended reservoirs of low density, cool neutral gas.
@article{arxiv.2009.08984,
title = {Observations of [OI]63micron line emission in main-sequence galaxies at z~1.5},
author = {J. Wagg and M. Aravena and D. Brisbin and I. Valtchanov and C. Carilli and E. Daddi and H. Dannerbauer and R. Decarli and T. Diaz-Santos and D. Riechers and M. Sargent and F. Walter},
journal= {arXiv preprint arXiv:2009.08984},
year = {2020}
}