Young stellar populations in the solar neighbourhood
Bibliographic record
Abstract
Stellar X-ray surveys play an important role in understanding the star formation history in our Galaxy in the last billion years (the scale time of coronal activity evolution). In particular, the comparison of observed counts in a given sky direction with predictions by Galactic models can put constraints on the spatial distribution and stellar birthrate of stellar populations. We present the results of our study of the stellar content of the Galaxy in the Solar vicinity using the results of the XMM-Newton Bright Serendipitous Survey (XBSS) Bright Source Sample (BSS) and the ROSAT North Ecliptic Pole survey (NEP). We have used the computational model XCOUNT for predicting the number of coronal sources and their spectral type distribution in the surveyed area. The comparison of the predictions with the observations supports a scenario with an increasing stellar formation rate during the last billion years. Nevertheless, we observe an excess of dwarf FGK stars in the observations, which can be due to both the existence of a young stellar population or to a number of M stars in binary systems with a yellow primary.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 0.002 |
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".