Uncovering the absorbed atomic Universe with the [OI]63um line
Carlos De Breuck (ESO), Kevin C. Harrington (JAO/NAOJ/ESO/UDP), Wout Hermans (Gent), Luke Maud (ESO), Aniket Bhagwat (MPA), Ilse De Looze (Gent), Bo Peng (MPA), Amit Vishwas (Cornell), Benedetta Casavecchia (MPA), and Andreas Lundgren (LAM)

TL;DR
This study presents the first systematic survey of the [OI]63um line at z>4, revealing widespread absorption and complex ISM structures in high-redshift dusty star-forming galaxies, with implications for star formation diagnostics.
Contribution
It uncovers strong [OI]63um absorption in high-redshift galaxies and links this to high optical depth regions, advancing understanding of ISM conditions in early universe starbursts.
Findings
[OI]63um absorption detected in 10 of 12 galaxies
Absorption occurs in compact, high optical depth regions
High optical depth limits [OI]63um as a star formation tracer
Abstract
We report the discovery of strongly absorbed [OI]63um in a sample of 12 DSFGs at 4.2<z<5.8 selected from the SPT survey. This is the first systematic survey of the [OI]63um fine-structure line at z>4. Using ALMA Bands 9 and 10, we obtain spatially and spectrally resolved observations that probe the interstellar medium on sub-kpc scales. Despite reaching sensitivities 10-100x deeper than most previous studies, we detect [OI]63um in emission in only 2 sources at low significance, with the remaining galaxies yielding stringent non-detections over the full velocity range covered by robust detections of other far-infrared lines, including [CII] and [NII]205um. We identify several compact (0.05-0.2") regions having [OI]63um absorption against the far-infrared dust continuum, some of which are possibly reaching below rest-frame CMB radiation level. We also detect narrow, spatially localised…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
