TRANSIENT EXTREMELY SOFT X-RAY EMISSION FROM THE UNUSUALLY BRIGHT CATACLYSMIC VARIABLE IN THE GLOBULAR CLUSTER M3: A NEW CV X-RAY LUMINOSITY RECORD?
Bibliographic record
Abstract
We observed the accreting white dwarf (WD) 1E1339.8+2837 (1E1339) in the globular cluster M3 in 2003 November, 2004 May, and 2005 January, using the Chandra ACIS-S detector. The source was observed in 1992 to possess traits of a supersoft X-ray source (SSS), with a 0.1–2.4 keV luminosity as large as 2 × 10 35 erg s −1 , after which time the source's luminosity fell by roughly two orders of magnitude, adopting a hard X-ray spectrum more typical of cataclysmic variables (CVs). Our observations confirm 1E1339's hard CV-like spectrum, with photon index Γ = 1.3 ± 0.2. We found 1E1339 to be highly variable, with a 0.5–10 keV luminosity ranging from (1.4 ± 0.3) × 10 34 erg s −1 to 8.5 +4.9 − 4.6 × 10 32 erg s −1 , with 1E1339's maximum luminosity being perhaps the highest yet recorded for hard X-ray emission from a WD. In 2005 January, 1E1339 displayed substantial low-energy emission below ∼0.3 keV. Although current Chandra responses cannot properly model this emission, its bolometric luminosity appears comparable to or greater than that of the hard spectral component. This raises the possibility that the supersoft X-ray emission seen from 1E1339 in 1992 may have shifted to the far-UV.
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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 | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 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) | 0.000 | 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 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".