MIGHTEE-Hi: Evolution of Hi Scaling Relations of Star-forming Galaxies at z < 0.5*

Abstract We present the first measurements of H i galaxy scaling relations from a blind survey at z > 0.15. perform spectral stacking 9023 spectra star-forming galaxies undetected in 0.23 < 0.49, extracted MIGHTEE-H Early Science data cubes, acquired with MeerKAT radio telescope. stack bins properties (stellar mass M * , star formation rateSFR, and specific rate sSFR, sSFR ? /SFR), obtaining ?5 ? detections most cases, strongest -stacking to date this redshift range. With these detections, we are able measure probed interval, finding evidence for moderate evolution median our sample med ? 0.37 0. In particular, low- ( log 10 ( M * stretchy="true">/ ? stretchy="false">) ? 9 ) experience strong depletion (?0.5 dex ${\mathrm{log}}_{10}({M}_{{\rm{H}}\,{\rm\small{I}}}/{M}_{\odot })$?> H mathsize="small" mathvariant="normal">I ), while massive 11$?> 11 keep their nearly unchanged. When looking activity, highly evolve significantly I f where / fixed SFR (sSFR), lowest (sSFR) show no evolution. These findings suggest scenario which have experienced during last ?5 Gyr, undergone significant replenishment through some accretion mechanism, possibly minor mergers. Interestingly, results good agreement predictions simba simulation. conclude that work sets novel important observational constraints on relations.