A Major Soft Gamma Repeater-like Outburst and Rotation Glitch in the No-longer-so-anomalous X-Ray Pulsar 1E 2259+586
Bibliographic record
Abstract
We report a major outburst from the anomalous X-ray pulsar 1E 2259+586, in which over 80 X-ray bursts were detected in 4 hr using the Rossi X-Ray Timing Explorer . The bursts range in duration from 2 ms to 3 s and have fluences in the 2-10 keV band that range from 3 × 10 -11 to 5 × 10 -9 ergs cm -2 . We simultaneously observed increases of the pulsed and persistent X-ray emission by over an order of magnitude relative to quiescent levels. Both decayed significantly during the course of our 14 ks observation. Correlated spectral hardening was also observed, with the spectrum softening during the observation. In addition, we observed a pulse profile change, in which the amplitudes of the two peaks in the pulse profile were swapped. The profile relaxed back to its pre-outburst morphology after ~6 days. The pulsar also underwent a sudden spin-up (Δν/ν = 4 × 10 -6 ), followed by a large (factor of ~2) increase in spin-down rate that persisted for more than 18 days. We also observed, using the Gemini North telescope, an infrared enhancement, in which the K s (2.15 μm) flux increased, relative to that measured in a observation made in 2000, by a factor of ~3, 3 days post-outburst. The IR counterpart then faded by a factor of ~2 1 week later. In addition, we report an upper limit of 50 μJy on radio emission at 1.4 GHz 2 days post-outburst. The X-ray properties of this outburst are like those seen only in soft gamma repeaters. This conclusively unifies anomalous X-ray pulsars and soft gamma repeaters, as predicted uniquely by the magnetar model.
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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 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".