Origin of the discrepancy in the [N/Fe]–[Fe/H] trend relative to APOGEE

Determine the cause of the observed discrepancy between the [N/Fe]–[Fe/H] abundance trend obtained from the Data-Driven Payne analysis of DESI Early Data Release spectra and the trend measured by APOGEE DR17.

Background

When comparing DESI DD-Payne abundance trends with those from APOGEE DR17, most elements show consistent behavior. However, nitrogen displays a slightly different [N/Fe]–[Fe/H] trend.

The authors explicitly note that the reason for this discrepancy is unclear, leaving an unresolved question about the origin of the difference between surveys for nitrogen.