2021/10/31 by Connor Hayden-Pawson, Mirko Curti, R. Maiolino +21 · 1 citation
Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Metallicity #Nitrogen #Physics #Redshift #Sky #Star formation #Stellar mass #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stac584
23 pages, 11 figures, Accepted for publication in Monthly Notices of the Royal Astronomical Society
openalex publication_date 2022/03/02 · openalex created_date 2022/03/05 · arxiv created 2022/03/09 · arxiv updated 2022/03/10 · openalex updated_date 2026/08/01
We present a comparison of the nitrogen-to-oxygen ratio (N/O) in 37 high-redshift galaxies at z∼2 taken from the KMOS Lensed Emission Lines and VElocity Review (KLEVER) Survey with a comparison sample of local galaxies, taken from the Sloan Digital Sky Survey (SDSS). The KLEVER sample shows only a mild enrichment in N/O of +0.1 dex when compared to local galaxies at a given gas-phase metallicity (O/H), but shows a depletion in N/O of -0.36 dex when compared at a fixed stellar mass (M_*). We find a strong anti-correlation in local galaxies between N/O and SFR in the M_*-N/O plane, similar to the anti-correlation between O/H and SFR found in the mass-metallicity relation (MZR). We use this anti-correlation to construct a fundamental nitrogen relation (FNR), analogous to the fundamental metallicity relation (FMR). We find that KLEVER galaxies are consistent with both the FMR and the FNR. This suggests that the depletion of N/O in high-z galaxies when considered at a fixed M_* is driven by the redshift-evolution of the mass-metallicity relation in combination with a near redshift-invariant N/O-O/H relation. Furthermore, the existence of an fundamental nitrogen relation suggests that the mechanisms governing the fundamental metallicity relation must be probed by not only O/H, but also N/O, suggesting pure-pristine gas inflows are not the primary driver of the FMR, and other properties such as variations in galaxy age and star formation efficiency must be important.