Phenomenology of pulsar B0809+74's rotating subbeam 
system

Rankin, Joanna M.; Ramachandran, R.; Suleymanova, S. A.

doi:10.1051/0004-6361:20042310

Cited by 14 publications

(13 citation statements)

References 31 publications

(42 reference statements)

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“…Evidence in other pulsar contexts does indeed suggest that a partial or complete blockage of the radiation from either the leading or trailing side of the magnetic axis longitude does occur. The most interesting recent evidence about the phenomenon comes from the studies of the drifting‐subpulse patterns of pulsars B0943+10 (Deshpande & Rankin 1999, 2001; Rankin & Ramachandran 2003; Rankin & Suleymanova 2006) and B0809+74 (Rankin et al 2005, 2006a,b), where the rotating‐subbeam ‘carousel’ is usually visible only at longitudes later and earlier than the central longitude, respectively. Fascinatingly, however, this is not always the case: in B0809+74, the ‘absorption’ characteristics are frequency dependent and are possibly in some cases specific to one polarization mode.…”

Section: How Are ‘Events’ To Be Understood?mentioning

confidence: 99%

Bistable profile illumination in pulsars B0919+06 and B1859+07

Rankin

Rodríguez

Wright

2006

Monthly Notices of the Royal Astronomical Society

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Unusual single-pulse behaviour has been identified in two pulsars, B0919+06 and B1859+07. Both stars normally emit bright subpulses in a region near the trailing edge of their profile. However, they occasionally undergo 'events', whereby the emission longitude gradually decreases by about their profile width, remains in this position for typically several tens of pulses, and then gradually returns over a few pulses to the usual longitude. The effect bears some resemblance to a profile 'mode change', but here the effect is gradual and episodic. On close inspection, the separate profiles of the normal and 'event' in each pulsar emission reveal a broad and complex structure -but one which may be understood in terms of the geometry of a conical beam. Possibly the effect entails an extreme example of variable 'absorption' within the magnetosphere, as suspected in other pulsars. Alternatively, it may be caused by intrinsic changes in the emission within the pulsar's beam.

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Section: How Are ‘Events’ To Be Understood?mentioning

confidence: 99%

Bistable profile illumination in pulsars B0919+06 and B1859+07

Rankin

Rodríguez

Wright

2006

Monthly Notices of the Royal Astronomical Society

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“…Apart from these, pulsars also display well known phenomena such as drifting subpulses (Backer 1970a), polarisation modes (Gangadhara 1997;van Straten & Tiburzi 2017), microstructure (Johnston et al 2001) and profile 'absorption' where part of the profile is obscured, (see e.g. Rankin et al 2006b). A recent addition to these phenomena are 'emission shifts' where the emission briefly shifts to an earlier longitude, first identified by Rankin et al (2006a) for PSRs J1901+0716 (B1859+07) and J0922+0638 (B0919+06).…”

Section: Introductionmentioning

confidence: 99%

Multifrequency behaviour of the anomalous events of PSR J0922+0638

Shaifullah

Tiburzi

Osłowski

et al. 2018

Monthly Notices of the Royal Astronomical Society: Letters

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PSR J0922+0638 (B0919+06) shows unexplained anomalous variations in the on-pulse phase, where the pulse appears to episodically move to an earlier longitude for a few tens of rotations before reverting to the usual phase for approximately several hundred to more than a thousand rotations. These events, where the pulse moves in phase by up to 5°, have been previously detected in observations from ∼300 to 2000 MHz. We present simultaneous observations from the Effelsberg 100-m radio telescope at 1350 MHz and the Bornim (Potsdam) station of the LOw Frequency ARray at 150 MHz. Our observations present the first evidence for an absence of the anomalous phase-shifting behaviour at 150 MHz. Instead, the observed intensity at the usual pulse-phase typically decreases, often showing a pseudo-nulling feature corresponding to the times when phase shifts are observed at 1350 MHz. The presence of weak emission at the usual pulse-phase supports the theory that these shifts may result from processes similar to the 'profile-absorption' expected to operate for PSR J0814+7429 (B0809+74). A possible mechanism for this could be intrinsic variations of the emission within the pulsar's beam combined with absorption by expanding shells of electrons in the line of sight.

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“…In the present case, our fluctuation spectral analysis revealed a single high-Q feature in an otherwise featureless spectrum, providing an estimate of P 3 to be 10.8529 ± 0.0007 spin periods 5 . Using the geometrical parameters 6 from Rankin et al (2006), and assuming a total of 9 sub-beams, 2048 periods long pulse sequences are cartographically transformed to map the emission pattern in each of the sub-bands. While further details of analysis on this pulsar and the assumed carousel circulation period would be discussed elsewhere, here we present a preliminary tomograph of the polar emission region of this pulsar in Figure 12, using data in the lowest 4 frequency bands having adequate signal-to-noise ratio.…”

Section: Observations and Preliminary Resultsmentioning

confidence: 99%

Rri-GBT Multi-Band Receiver: Motivation, Design, and Development

Maan

Deshpande

Chandrashekar

et al. 2013

ApJS

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We report the design and development of a self-contained multi-band receiver (MBR) system, intended for use with a single large aperture to facilitate sensitive & high time-resolution observations simultaneously in 10 discrete frequency bands sampling a wide spectral span (100-1500 MHz) in a nearly log-periodic fashion. The development of this system was primarily motivated by need for tomographic studies of pulsar polar emission regions. Although the system design is optimized for the primary goal, it is also suited for several other interesting astronomical investigations. The system consists of a dual-polarization multi-band feed (with discrete responses corresponding to the 10 bands pre-selected as relatively RFI-free), a common wide-band RF front-end, and independent back-end receiver chains for the 10 individual sub-bands. The raw voltage time-sequences corresponding to 16 MHz bandwidth each for the two linear polarization channels -2and the 10 bands, are recorded at the Nyquist rate simultaneously. We present the preliminary results from the tests and pulsar observations carried out with the Green Bank Telescope using this receiver. The system performance implied by these results, and possible improvements are also briefly discussed.

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Phenomenology of pulsar B0809+74's rotating subbeam system

Cited by 14 publications

References 31 publications

Bistable profile illumination in pulsars B0919+06 and B1859+07

Bistable profile illumination in pulsars B0919+06 and B1859+07

Multifrequency behaviour of the anomalous events of PSR J0922+0638

Rri-GBT Multi-Band Receiver: Motivation, Design, and Development

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