Mightee-hi: Evolution of hi scaling relations of star-forming galaxies at z < 0.5*
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Date
2022
Journal Title
Journal ISSN
Volume Title
Publisher
IOP Publishing
Abstract
We present the first measurements of H I galaxy scaling relations from a blind survey at z > 0.15. We perform
spectral stacking of 9023 spectra of star-forming galaxies undetected in H I at 0.23 < z < 0.49, extracted from
MIGHTEE-H I Early Science data cubes, acquired with the MeerKAT radio telescope. We stack galaxies in
bins of galaxy properties (stellar mass M*, star formation rateSFR, and specific star formation rate sSFR, with
sSFR ≡ M*/SFR), obtaining 5σ detections in most cases, the strongest H I-stacking detections to date in this
redshift range. With these detections, we are able to measure scaling relations in the probed redshift interval,
finding evidence for a moderate evolution from the median redshift of our sample zmed ∼ 0.37 to z ∼ 0. In
particular, low-M* galaxies ( ~ * log 9 10( ) M M ) experience a strong H I depletion (∼0.5 dex in
log10( ) M M H I ), while massive galaxies ( ~ * log 11 10( ) M M ) keep their H I mass nearly unchanged. When
looking at the star formation activity, highly star-forming galaxies evolve significantly in MH I ( fH I, where
fH I ≡ MH I/M*) at fixed SFR (sSFR), while at the lowest probed SFR (sSFR) the scaling relations show no
evolution.
Description
Keywords
Astronomy, Astrophysics, Galaxy formation, Galaxy evolution, Radio astronomy
Citation
Sinigaglia, F. et al. (2022). Mightee-hi: Evolution of hi scaling relations of star-forming galaxies at z < 0.5*. Astrophysical Journal Letters, 935(1), L13. https://doi.org/10.3847/2041-8213/ac85ae