The Properties of the Star-Forming Interstellar Medium at z=0.8-2.2 from\n HiZELS - II: Star-Formation and Clump Scaling Laws in Gas Rich, Turbulent\n Disks
Bibliographic record
Abstract
We present adaptive optics assisted integral field spectroscopy of nine\nHalpha-selected galaxies at z=0.84--2.23 selected from the HiZELS narrow-band\nsurvey. Our observations map the star-formation and kinematics of these\nrepresentative star-forming galaxies on ~kpc-scales. We demonstrate that within\nthe ISM of these galaxies, the velocity dispersion of the star-forming gas\n(\\sigma) follows a scaling relation \\sigma\\propto\\Sigma_SFR^(1/n)+constant\n(where \\Sigma_SFR is the star formation surface density and the constant\nincludes the stellar surface density). Assuming the disks are marginally stable\n(Toomre Q=1), we show that this follows from the Kennicutt-Schmidt relation\n(\\Sigma_SFR = A\\Sigma_gas^n), and we use the data to derive best fit parameters\nof n=1.34+/-0.15 and A=3.4_(-1.6)^(+2.5)x10^(-4)Mo/yr/kpc^2, consistent with\nthe local relation and implying cold molecular gas masses of M_gas=10^(9-10)Mo\nand molecular gas fractions M_gas/(M_gas+Mstars)=0.3+/-0.1, with a range of\n10-75%. These values confirm the high gas fractions for high-redshift\nstar-forming galaxies, independent of CO-H_2 conversion factor. We also\nidentify eleven ~kpc-scale star-forming regions (clumps) within our sample and\nshow that their sizes are comparable to the wavelength of the fastest growing\nunstable mode. The luminosities and velocity dispersions of these clumps follow\nthe same scaling relations as local HII regions, although their star formation\ndensities are a factor 15+/-5x higher than typically found locally. We discuss\nhow the clump properties are related to the disk, and show that their high\nmasses and luminosities are a consequence of the high disk surface density.\n
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".