Caltech Faint Galaxy Redshift Survey. XIV. Galaxy Morphology in the Hubble Deep Field (North) and Its Flanking Fields to z = 1.2*
Bibliographic record
Abstract
Morphological classifications are reported for Hubble Space Telescope images of 241 galaxies in the Hubble Deep Field and its flanking fields with measured redshifts in the interval 0.25 < z < 1.2, drawn from a magnitude-limited redshift survey to R = 24.0. The galaxies are divided into three groups with redshifts in the intervals 0.25–0.6, 0.6–0.8, and 0.8–1.2. R_(606) images from the first group and I_(814) images from the second and third groups are compared with B-band images of nearby galaxies. All classifications were therefore made at approximately the same rest wavelength. Selection biases are discussed. We corroborate and extend the results of earlier investigations by observing that \n1.\tMost intermediate- and late-type galaxies with z ≳ 0.5 have morphologies that are dramatically different from those of local galaxies and cannot be shoehorned into the Hubble "tuning fork" classification scheme; \n2.\tGrand-design spirals appear to be rare or absent for z ≳ 0.3; \n3.\tMany Sa and Sb spirals with z ≳ 0.6 do not exhibit well-defined spiral arms, and the arms of distant Sc galaxies appear more chaotic than those of their nearby counterparts; \n4.\tThe fraction of all galaxies that are of types Sc and Scd drops from 23% at z ~ 0 to 5% for z > 0.6. \n5.\tBarred spirals are extremely rare for z ≳ 0.5; \n6.\tRoughly one in five galaxies with z ≳ 0.8 is a compact objects that resembles local E, S0, or Sa galaxies. \n7.\tPeculiar galaxies are more common beyond z = 0.3, especially among late-type spirals, than they are at z ~ 0; \n8.\tMerging galaxies, particularly those with three or more components, also become more common with increasing redshift. \nOn the basis of these and similar observations, it is inferred that the development of pronounced spiral structure was delayed until ~5 Gyr and that most bulges are probably not formed by disintegrating bars. Major morphological changes were still taking place only ~5 Gyr ago, even though changes in the integrated light of most galaxies were then much slower than they were ~10 Gyr ago.
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.
How this classification was reachedexpand
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 | 0.001 | 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 | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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 teacher head, 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".