The puzzling nature of dwarf-sized gas poor disk galaxies
Bibliographic record
Abstract
N early-type dwarf galaxiesThis thesis is about red low-mass galaxies in the Virgo cluster.Such a characterization of the topic is obviously inexact, but with the simplicity comes one advantage: it is descriptive and independent of naming conventions.Low-mass lacks a precise definition and is not a direct observable.Often the term dwarf galaxy is used, instead.How is a dwarf galaxy different from a normal galaxy?The word suggests that it is smaller.However, in astronomical terms most often a limit in galaxy brightness is used for the separation.The dividing line is usually taken somewhere between M B -18 mag (e.g.Boselli et al., 2008) and M B -16 mag (e.g.Ferguson & Binggeli, 1994).The large span of choices reflects the fact that it is even disputed whether or not the dwarf galaxies are really different from the brighter galaxies.There is a large variety of different dwarf galaxy types (Fig. 1.1) and even more diversity in the names for these types.As Tolstoy et al. ( 2009) state: "The taxonomy of dwarf galaxies typically opens a Pandora's box."For example, Grebel (2001) lists: dwarf spirals (S0, Sa, Sb, Sc, and Sd), Magellanic irregulars (Sm, Sdm), blue compact dwarf galaxies (BCDs), dwarf irregulars (dIrr), dwarf ellipticals (dE), dwarf spheroidal galaxies (dSph), and tidal dwarf galaxies.Tolstoy et al. (2009) cover in addition ultra-compact dwarf galaxies (UCDs) and ultra-faint dwarfs (uFd).The galaxies in focus in our study are red, which excludes spirals, Sm, Sdm, BCD, and dIrr.With our data sources and the interest in detailed morphologies of galaxies we are restricted to dEs.The other red low-mass galaxies are too small and faint at the distance of the Virgo cluster (d = 16.5 Mpc, Mei et al. 2007; UCDs:
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 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".