Deep Searches for Radio Pulsations and Bursts from Four Southern Anomalous X‐Ray Pulsars
Bibliographic record
Abstract
We have searched for persistent radio pulsations, bright single pulses, and bursts from four southern anomalous X-ray pulsars (AXPs). Deep observations were conducted at 1.4 GHz in 1999 July and August with the Parkes 64 m telescope. For all of the target AXPs, the upper limits on integrated pulsed emission are ~0.02 mJy, while the limits on the flux of single pulses are ~1 Jy or better. The corresponding radio luminosity limits are significantly below the observed luminosities of the majority of the observed radio pulsars, and they are significantly below the radio luminosity of XTE J1810-197, the only AXP known thus far to emit radio pulsations, at the epoch when radio pulses were first detected from this source. Our null results support the hypothesis that pulsed radio emission from AXPs is only present in conjunction with X-ray outburst activity. However, we cannot rule out the possibility that pulsed radio emission is present, but that it is too weak to be detected in our observations, or that unfavorable viewing geometries prevent this emission from being seen by terrestrial observers. Given the possible association between the radio emission and transient X-ray behavior of XTE J1810-197, continued radio searches of these and other AXPs at different epochs are warranted, particularly after periods of X-ray burst activity.
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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 | 0.001 |
| 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 | 0.001 | 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".