Interpreting ALMA non-detections of JWST super-early galaxies. Issue 1 (2nd January 2023)

• Record Type: Journal Article
• Authors: Kohandel, M; Ferrara, A; Pallottini, A; Vallini, L; Sommovigo, L; Ziparo, F
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 520:Issue 1(2023)
• Page Start: L16
• Page End: L20
• Publication Date: 2023-01-02
• Subjects: methods: numerical -- galaxies: evolution -- galaxies: formation -- galaxies: high-redshift -- galaxies: ISM -- infrared: general; Astronomy -- Research -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnrasl/slac166
• Languages: English
• ISSNs: 1745-3933

Abstract

ABSTRACT: Recent attempts to detect [O iii ] 88$\, \mu$ m emission from super-early ( z > 10) galaxy candidates observed by JWST have been unsuccessful. Non-detections can be either due to wrong photometric redshifts or to the faintness of the line in such early systems. By using zoom-in simulations, we show that if redshifts of these galaxies are confirmed, they are faint and mostly fall below the local metal-poor $\rm [O\, {\small III}]-SFR$ relation as a result of their low ionization parameter, U ion ≲ 10 −3 . Such low U ion values are found in galaxies that are in an early assembly stage, and whose stars are still embedded in high-density natal clouds. However, the most luminous galaxy in our sample ($\rm {log}[L_{\rm {[O\, {\small III}]}}/\mathrm{L}_\odot ] = 8.4$, U ion ≈ 0.1) could be detected by ALMA in only 2.8 h.