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

Francesco Sinigaglia*, Giulia Rodighiero, Ed Elson, Mattia Vaccari, Natasha Maddox, Bradley S. Frank, Matt J. Jarvis, Tom Oosterloo, Romeel Davé, Mara Salvato, Maarten Baes, Sabine Bellstedt, Laura Bisigello, Jordan D. Collier, Robin H. W. Cook, Luke J. M. Davies, Jacinta Delhaize, Simon P. Driver, Caroline Foster, Sushma KurapatiClaudia del P. Lagos, Christopher Lidman, Pavel E. Mancera Piña, Martin J. Meyer, K. Moses Mogotsi, Hengxing Pan, Anastasia A. Ponomareva, Isabella Prandoni, Sambatriniaina H. A. Rajohnson, Aaron S. G. Robotham, Mario G. Santos, Srikrishna Sekhar, Kristine Spekkens, Jessica E. Thorne, Jan M. van der Hulst, O. Ivy Wong

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

We present the first measurements of HI galaxy scaling relations from a blind survey at z>0.15. We perform spectral stacking of 9023 spectra of star-forming galaxies undetected in HI at 0.23<z<0.49, extracted from MIGHTEE-HI Early Science datacubes, acquired with the MeerKAT radio telescope. We stack galaxies in bins of galaxy properties (M∗, SFR, and sSFR, with sSFR≡M∗/SFR), obtaining ≳5σ detections in most cases, the strongest HI-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 (log10(M∗/M⊙)∼9) experience a strong HI depletion (∼0.5 dex in log10(MHI/M⊙)), while massive galaxies (log10(M∗/M⊙)∼11) keep their HI mass nearly unchanged. When looking at the star formation activity, highly star-forming galaxies evolve significantly in MHI (fHI, where fHI≡M/M∗) at fixed SFR (sSFR), while at the lowest probed SFR (sSFR) the scaling relations show no evolution. These findings suggest a scenario in which low-M∗ galaxies have experienced a strong HI depletion during the last ∼4 Gyr, while massive galaxies have undergone a significant HI replenishment through some accretion mechanism, possibly minor mergers. Interestingly, our results are in good agreement with the predictions of the SIMBA simulation. We conclude that this work sets novel important observational constraints on galaxy scaling relations.
Original languageEnglish
Article numberL13
Pages (from-to)1-9
Number of pages9
JournalAstrophysical Journal Letters
Issue number1
Publication statusPublished - 12 Aug 2022

Keywords / Materials (for Non-textual outputs)

  • astro-ph.GA
  • astro-ph.CO


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