@article{2024NatAs...8..368P,
 abstract = {Heavy element accumulation and stellar mass assembly are fundamental
processes in the formation and evolution of galaxies. However,
the key elements that govern them, such as gas accretion and
outflow, are not fully understood. This is especially true for
luminous and massive galaxies, which usually suffer strong
feedback as massive outflows and large-scale gas accretion
triggered by galaxy interactions. Using a sample of 77 luminous
infrared (IR) galaxies, we derive chemical abundances using new
diagnostics based on nebular IR lines, which peer through their
dusty medium and allow us to include the obscured metals. In
contrast to optically based studies, our analysis reveals that
most luminous IR galaxies remain close to the mass-metallicity
relation. Four galaxies with extreme star formation rates (>60
M$_\ensuremathødot$ yr$^\ensuremath-1$) in their
late-merger stages show strongly depressed metallicities (12 +
log(O/H) \ensuremath≈ 7.7-8.1) along with solar-like
N/O ratios, indicative of gas mixing processes and suggesting
the action of massive infall of metal-poor gas in a short phase,
eventually followed by rapid enrichment. These results challenge
the classical gas equilibrium scenario applied to main-sequence
galaxies, suggesting that chemical enrichment and stellar-mass
growth in luminous IR galaxies likely occur via mergers, driving
these galaxies out of chemical equilibrium.},
 adsnote = {Provided by the SAO/NASA Astrophysics Data System},
 adsurl = {https://ui.adsabs.harvard.edu/abs/2024NatAs...8..368P},
 archiveprefix = {arXiv},
 author = {Pérez-Dı́az, Borja and Pérez-Montero, Enrique and Fernández-Ontiveros, Juan A. and V\ĺchez, José M. and Amor\',́ Ricardo},
 doi = {10.1038/s41550-023-02171-x},
 eprint = {2306.14843},
 journal = {Nature Astronomy},
 keywords = {Astrophysics - Astrophysics of Galaxies},
 month = {March},
 pages = {368-376},
 primaryclass = {astro-ph.GA},
 title = {A departure from the mass-metallicity relation in merging galaxies due to an infall of metal-poor gas},
 volume = {8},
 year = {2024}
}