Atomic Hydrogen Scaling Relations at z ≈ 0.35
Abstract
The atomic hydrogen (H I) properties of star-forming galaxies in the local universe are known to correlate with other galaxy properties via the "H I scaling relations." The redshift evolution of these relations serves as an important constraint on models of galaxy evolution. However, until recently, there were no estimates of the H I scaling relations at cosmological distances. Using data from a deep Giant Metrewave Radio Telescope H I 21 cm survey of the Extended Groth Strip, and the technique of spectral-line stacking, we determine the scaling relation between the H I mass and the stellar mass for star-forming galaxies at z ≈ 0.35. We use this measurement, along with the main-sequence relation in galaxies, to infer the dependence of the H I depletion timescale of these galaxies on their stellar mass. We find that massive star-forming galaxies at z ≈ 0.35, with stellar mass M * ≳ 109.5 M ⊙, are H I-poor compared to local star-forming galaxies of a similar stellar mass. However, their characteristic H I depletion time is lower by a factor of ≈5 than that of their local analogs, indicating a higher star formation efficiency at intermediate redshifts (similar to that at z ≈ 1). While our results are based on a relatively small cosmic volume and could thus be affected by cosmic variance, the short characteristic H I depletion timescales (≲3 Gyr) of massive star-forming galaxies at z ≈ 0.35 indicate that they must have acquired a significant amount of neutral gas through accretion from the circumgalactic medium over the past 4 Gyr, to avoid quenching of their star formation activity.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2023
- DOI:
- 10.3847/2041-8213/acd0b3
- arXiv:
- arXiv:2305.01389
- Bibcode:
- 2023ApJ...950L..18B
- Keywords:
-
- Galaxy evolution;
- Radio spectroscopy;
- H I line emission;
- High-redshift galaxies;
- 594;
- 1359;
- 690;
- 734;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted for publication in the Astrophysical Journal Letters