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 four hours 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 x 10^{-11} to 5 x 10^{-9} erg 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 (df/f = 4 x 10^{-6}), followed by a large (factor of \~2) increase in spin-down rate which persisted for >18 days. We also observed, using the Gemini-North telescope, an infrared enhancement, in which the K_s (2.15 um) flux increased, relative to that measured in a observation made in 2000, by a factor of ~3, three days post-outburst. The IR counterpart then faded by a factor of ~2 one week later. In addition, we report an upper limit of 50 uJy on radio emission at 1.4 GHz two 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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 teacher head, 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".