TWO LONG-TERM INTERMITTENT PULSARS DISCOVERED IN THE PALFA SURVEY
Bibliographic record
Abstract
ABSTRACT We report the discovery of two long-term intermittent radio pulsars in the ongoing Pulsar Arecibo L-Band Feed Array survey. Following discovery with the Arecibo Telescope, extended observations of these pulsars over several years at Jodrell Bank Observatory have revealed the details of their rotation and radiation properties. PSRs J1910+0517 and J1929+1357 show long-term extreme bimodal intermittency, switching between active (ON) and inactive (OFF) emission states and indicating the presence of a large, hitherto unrecognized underlying population of such objects. For PSR J1929+1357, the initial duty cycle was f ON = 0.008, but two years later, this changed quite abruptly to f ON = 0.16. This is the first time that a significant evolution in the activity of an intermittent pulsar has been seen, and we show that the spin-down rate of the pulsar is proportional to the activity. The spin-down rate of PSR J1929+1357 is increased by a factor of 1.8 when it is in active mode, similar to the increase seen in the other three known long-term intermittent pulsars. These discoveries increase the number of known pulsars displaying long-term intermittency to five. These five objects display a remarkably narrow range of spin-down power ( ) and accelerating potential above their polar caps. If confirmed by further discoveries, this trend might be important for understanding the physical mechanisms that cause intermittency.
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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 | 0.001 | 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".