The properties of the star-forming interstellar medium at<i>z</i> = 0.84-2.23 from HiZELS: mapping the internal dynamics and metallicity gradients in high-redshift disc galaxies
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
We present adaptive optics assisted, spatially resolved spectroscopy of a sample of nine Hα-selected galaxies at z = 0.84–2.23 drawn from the HiZELS narrow-band survey. These galaxies have star formation rates of 1–27 M⊙ yr−1 and are therefore representative of the typical high-redshift star-forming population. Our ∼kpc-scale resolution observations show that approximately half of the sample have dynamics suggesting that the ionized gas is in large, rotating discs. We model their velocity fields to infer the inclination-corrected, asymptotic rotational velocities. We use the absolute B-band magnitudes and stellar masses to investigate the evolution of the B-band and stellar-mass Tully–Fisher relationships. By combining our sample with a number of similar measurements from the literature, we show that, at fixed circular velocity, the stellar mass of star-forming galaxies has increased by a factor of 2.5 between z = 2 and 0, whilst the rest-frame B-band luminosity has decreased by a factor of ∼ 6 over the same period. Together, these demonstrate a change in mass-to-light ratio in the B band of Δ(M/LB)/(M/LB)z=0 ∼ 3.5 between z = 1.5 and 0, with most of the evolution occurring below z = 1. We also use the spatial variation of [N ii]/Hα to show that the metallicity of the ionized gas in these galaxies declines monotonically with galactocentric radius, with an average Δ log(O/H)/ΔR = −0.027 ± 0.005 dex kpc−1. This gradient is consistent with predictions for high-redshift disc galaxies from cosmologically based hydrodynamic simulations.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it