@article{4a8698baebaf4a77b22ca032a7a0fdf8,
title = "A dense, solar metallicity ISM in the z = 4.2 dusty star-forming galaxy SPT 0418-47",
abstract = "We present a study of six far-infrared fine structure lines in the z = 4.225 lensed dusty star-forming galaxy SPT 0418-47 to probe the physical conditions of its interstellar medium (ISM). In particular, we report Atacama Pathfinder EXperiment (APEX) detections of the [OI] 145 μm and [OIII] 88 μm lines and Atacama Compact Array (ACA) detections of the [NII] 122 and 205 μm lines. The [OI] 145 μm/[CII] 158 μm line ratio is ∼5× higher compared to the average of local galaxies. We interpret this as evidence that the ISM is dominated by photo-dissociation regions with high gas densities. The line ratios, and in particular those of [OIII] 88 μm and [NII] 122 μm imply that the ISM in SPT 0418-47 is already chemically enriched to nearly solar metallicity. While the strong gravitational amplification was required to detect these lines with APEX, larger samples can be observed with the Atacama Large Millimeter/submillimeter Array (ALMA), and should allow observers to determine if the dense, solar metallicity ISM is common among these highly star-forming galaxies.",
keywords = "Galaxies: ISM, Galaxies: high-redshift, Submillimeter: ISM, Submillimeter: galaxies",
author = "{De Breuck}, Carlos and Axel Wei{\ss} and Matthieu B{\'e}thermin and Daniel Cunningham and Yordanka Apostolovski and Manuel Aravena and Melanie Archipley and Scott Chapman and Chen, {Chian Chou} and Jianyang Fu and Sreevani Jarugula and Matt Malkan and Mangian, {Amelia C.} and Phadke, {Kedar A.} and Reuter, {Cassie A.} and Gordon Stacey and Maria Strandet and Joaquin Vieira and Amit Vishwas",
note = "Funding Information: Acknowledgements. We thank the anonymous referee for useful suggestions, Myha Vuong for stimulating discussions on fine structure lines, and the APEX staff for their excellent support in obtaining the data. This publication is based on data acquired with the Atacama Pathfinder Experiment (APEX) under programme IDs 098.A-0513 (ESO), 0101.F-9522, and 093.F-9512 (both Max Planck). APEX is a collaboration between the Max-Planck-Institut fur Radioastronomie, the European Southern Observatory, and the Onsala Space Observatory. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.00133.T and ADS/JAO.ALMA#2018.1.01670.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The SPT is supported by the NSF through grant PLR-1248097, with partial support through PHY-1125897, the Kavli Foundation and the Gordon and Betty Moore Foundation grant GBMF 947. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. Publisher Copyright: {\textcopyright} ESO 2019.",
year = "2019",
month = nov,
day = "1",
doi = "10.1051/0004-6361/201936169",
language = "English (US)",
volume = "631",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
}