Simultaneous multi-frequency single pulse observations of pulsars

Abstract

We performed simultaneous observations at 326.5 MHz with the Ooty Radio Telescope and at 326, 610 and 1308 MHz with the Giant Meterwave Radio Telescope for a sample of 12 pulsars, where frequency dependent single pulse behaviour was reported. The single pulse sequences were analysed with fluctuation analysis, sensitive to both the average fluctuation properties (using longitude resolved fluctuation spectrum and two-dimensional fluctuation spectrum) as well as temporal changes in these (using sliding two-dimensional fluctuation spectrum ) to establish concurrent changes in subpulse drifting over the multiple frequencies employed. We report subpulse drifting in PSR J0934$-$5249 for the first time. We also report pulse nulling measurements in PSRs J0934$-$5249, B1508+55, J1822$-$2256, B1845$-$19 and J1901$-$0906 for the first time. Our measurements of subpulse drifting and pulse nulling for the rest of the pulsars are consistent with previously reported values. Contrary to previous belief, we find no evidence for a frequency dependent drift pattern in PSR B2016+28 implied by non-simultaneous observations by Oster et al. (1977). In PSRs B1237+25, J1822$-$2256, J1901$-$0906 and B2045$-$16, our longer and more sensitive observations reveal multiple drift rates with distinct P3. We increase the sample of pulsars showing concurrent nulling across multiple frequencies by more than 100 percent, adding 4 more pulsars to this sample. Our results confirm and further strengthen the understanding that the subpulse drifting and pulse nulling are broadband consistent with previous studies (Gajjar et al. 2014a; Rankin 1986; Weltevrede et al. 2007) and are closely tied to physics of polar gap.

22 pages, 44 figures, Single pulse studies of pulsars, accepted by A&A

References in corpus (12)

• TEMPO2, a new pulsar timing package. I: Overview
• Tempo2, a new pulsar timing package. II: The timing model and precision estimates
• Switched magnetospheric regulation of pulsar spin-down
• A periodically active pulsar giving insight into magnetospheric physics
• Pulsar Nulling and Mode Changing
• The subpulse modulation properties of pulsars at 92 cm and the frequency dependence of subpulse modulation
• Meterwavelength Single-pulse Polarimetric Emission Survey II: The phenomenon of Drifting Subpulses
• Simultaneous Single-Pulse Observations of Radio Pulsars: V. On the Broadband Nature of The Pulse Nulling Phenomenon in PSR B1133+16
• Frequency independent quenching of pulsed emission
• The Geometry of PSR B0031-07
• PONDER - A Real time software backend for pulsar and IPS observations at the Ooty Radio Telescope
• Inter-relationship between the Two Emission Cones of B1237+25

Cited by in corpus (11)

• The CHIME Pulsar Project: System Overview
• Subpulse Drifting, Nulling and Mode changing in PSR J1822$-$2256
• Jiamusi pulsar observations: III. Nulling of 20 pulsars
• Radio Pulsar Sub-Populations (I) : The Curious Case of Nulling Pulsars
• Revisiting the sub-pulse drifting phenomenon in PSR J1822-2256: Drift Modes, Sparks, and Emission Heights
• Detection of long nulls in PSR B1706$-$16, a pulsar with large timing irregularities
• The Discovery of Nulling and Mode Switching Pulsars with CHIME/Pulsar
• Detection of Echoes in PSR B1508+55 at frequencies below 100 MHz using the LWA1
• Discovery and follow-up of a quasiperiodically nulling and sub-pulse drifting pulsar with the Murchison Widefield Array
• Individual pulse emission from the diffuse drifter PSR J1401$-$6357 using the ultrawideband receiver on the Parkes radio telescope
• Independent discovery of a nulling pulsar with unusual sub-pulse drifting properties with the Murchison Widefield Array