The Three Hundred project: galaxy groups do not survive cluster infall
Bibliographic record
Abstract
ABSTRACT Galaxy clusters grow by accreting galaxies as individual objects, or as members of a galaxy group. These groups can strongly impact galaxy evolution, stripping the gas from galaxies, and enhancing the rate of galaxy mergers. However, it is not clear how the dynamics and structure of groups are affected when they interact with a large cluster, or whether all group members necessarily experience the same evolutionary processes. Using data from The Three Hundred project, a suite of 324 hydrodynamical resimulations of large galaxy clusters, we study the properties of 1340 groups passing through a cluster. We find that half of group galaxies become gravitationally unbound from the group by the first pericentre, typically just 0.5–1 Gyr after cluster entry. Most groups quickly mix with the cluster satellite population; only $8{{\ \rm per\ cent}}$ of infalling group haloes later leave the cluster, although for nearly half of these, all of their galaxies have become unbound, tidally disrupted or merged into the central by this stage. The position of galaxies in group-centric phase space is also important – only galaxies near the centre of a group (r ≲ 0.7R200) remain bound once a group is inside a cluster, and slow-moving galaxies in the group centre are likely to be tidally disrupted, or merge with another galaxy. This work will help future observational studies to constrain the environmental histories of group galaxies. For example, groups observed inside or nearby to clusters have likely approached very recently, meaning that their galaxies will not have experienced a cluster environment before.
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 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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".