SPECTRAL AND TIMING PROPERTIES OF THE MAGNETAR CXOU J164710.2–455216
Bibliographic record
Abstract
We report on spectral and timing properties of the magnetar CXOU J164710.2−455216 in the massive star cluster Westerlund 1. Using 11 archival observations obtained with Chandra and XMM-Newton over approximately 1000 days after the source's 2006 outburst, we study the flux and spectral evolution of the source. We show that the hardness of the source, as quantified by hardness ratio, blackbody temperature, or power-law photon index, shows a clear correlation with the 2–10 keV absorption-corrected flux and that the power-law component flux decayed faster than the blackbody component for the first ∼100 days. We also measure the timing properties of the source by analyzing data spanning approximately 2500 days. The measured period and period derivative are 10.610644(17) s (MJD 53999.06) and <4 × 10 −13 s s −1 (90% confidence) which imply that the spin-inferred dipolar magnetic field of the source is less than 7 × 10 13 G. This is significantly smaller than was suggested previously. We find evidence for a second flux increase, suggesting a second outburst between MJDs 55068 and 55832. Finally, based on a crustal cooling model, we find that the source's cooling curve can be reproduced if we assume that the energy was deposited in the outer crust and that the temperature profile of the star right after the 2006 outburst was relatively independent of density.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".