The frequency-dependent behaviour of subpulse drifting: I. Carousel geometry and emission heights of PSR B0031-07

Abstract

The carousel model of pulsar emission attributes the phenomenon of subpulse drifting to a set of discrete sparks located very near the stellar surface rotating around the magnetic axis. Here, we investigate the subpulse drifting behaviour of PSR B0031-07 in the context of the carousel model. We show that B0031-07's three drift modes (A, B, and C) can be understood in terms of a single carousel rotation rate if the number of sparks is allowed to change by an integral number, and where the different drift rates are due to (first-order) aliasing effects. This also results in harmonically-related values for P 3 (the time it takes a subpulse to reappear at the same pulse phase), which we confirm for B0031-07. A representative solution has [n_A, n_B, n_C] = [15, 14, 13] sparks and a carousel rotation period of P_4 = 16.4 P_1. We also investigate the frequency dependence of B0031-07's subpulse behaviour. We extend the carousel model to include the dual effects of aberration and retardation, including the time it takes the information about the surface spark configuration to travel from the surface up to the emission point. Assuming these effects dominate at B0031-07's emission heights, we derive conservative emission height differences of $\lesssim 2000$ km for mode A and $\lesssim 1000$ km for modes B and C as seen between 185 MHz and 610 MHz. This new method of measuring emission heights is independent of others that involve average profile components or the polarisation position angle curve, and thus provides a potentially strong test of the carousel model.

arXiv commentThis paper has been accepted for publication in ApJ

References in corpus (35)

• The Murchison Widefield Array: the Square Kilometre Array Precursor at low radio frequencies
• PSRCHIVE and PSRFITS An Open Approach to Radio Pulsar Data Storage and Analysis
• DSPSR: Digital Signal Processing Software for Pulsar Astronomy
• The subpulse modulation properties of pulsars at 21 cm
• Topology and Polarisation of Subbeams Associated With Pulsar 0943+10's ``Drifting''-Subpulse Emission: I. Analysis of Arecibo 430- and 111-MHz Observations
• Spark Model for Pulsar Radiation Modulation Patterns
• Understanding the radio emission geometry of PSR B0329+54
• The subpulse modulation properties of pulsars at 92 cm and the frequency dependence of subpulse modulation
• Drifting Sub-Pulse Analysis Using the Two-Dimensional Fourier Transform
• Mode Switching and Subpulse Drifting in PSR B0826-34
• Probing drifting and nulling mechanisms through their interaction in PSR B0809+74
• Pulsar Radio Emission Altitude from Curvature Radiation
• Frequency dependence of the drifting subpulses of PSR B0031-07
• Drifting, moding, and nulling: another look at pulsar B1918+19
• The High Time and Frequency Resolution Capabilities of the Murchison Widefield Array
• Low Frequency Observations of the Subpulse Drifter PSR J0034-0721 with the Murchison Widefield Array
• A model for the challenging "bi-drifting" phenomenon in PSR J0815+09
• Unraveling the drift behaviour of the remarkable pulsar PSR B0826-34
• On the long and short nulls, modes and interpulse emission of radio pulsar B1944+17
• A low frequency study of PSRs B1133+16, B1112+50, and B0031-07
• Giant pulses in Pulsar PSR B0031-07
• The frequency-dependence of drifting subpulse patterns
• The Geometry of PSR B0031-07
• Pulsar bi-drifting: implications for polar cap geometry
• Discovery of a remarkable subpulse drift pattern in PSR B0818-41
• Inter-relationship between the Two Emission Cones of B1237+25
• The origin of the frequency-dependent behaviour of pulsar radio profiles
• B0943+10: low-frequency study of subpulse periodicity in the Bright mode with LOFAR
• MWA Tied-Array Processing I: Calibration and Beamformation
• Dynamics of Charged Particles in the Radio Emission Region of Pulsar Magnetosphere
• MWA Tied-Array Processing II: Polarimetric Verification and Analysis of two Bright Southern Pulsars
• Results from multi-frequency observations of PSR B0826-34
• Variations of $P_2$ in subpulse drifting pulsars
• PSR B0809+74: Understanding Its Perplexing Subpulse-separation (P2) Variations
• Understanding the effects of geometry and rotation on pulsar intensity profiles

Cited by in corpus (9)

• The Thousand-Pulsar-Array programme on MeerKAT I: Science objectives and first results
• Revisiting the sub-pulse drifting phenomenon in PSR J1822-2256: Drift Modes, Sparks, and Emission Heights
• Discovery of a steep-spectrum low-luminosity pulsar with the Murchison Widefield Array
• Circular polarization in radio pulsar PSR B1451-68: coherent mode transitions and intrabeam interference
• PSR J0026-1955: A curious case of evolutionary subpulse drifting and nulling
• Individual pulse emission from the diffuse drifter PSR J1401$-$6357 using the ultrawideband receiver on the Parkes radio telescope
• Testing the circularity of PSR B0818-41's carousel
• Independent discovery of a nulling pulsar with unusual sub-pulse drifting properties with the Murchison Widefield Array
• Pushchino multibeams pulsar search -- III. Drift periods of pulsars from summed power spectra method