On the Geometry of Curvature Radiation and Implications for Subpulse Drifting

Abstract

The phenomenon of subpulse drifting offers unique insights into the emission geometry of pulsars, and is commonly interpreted in terms of a rotating carousel of "spark" events near the stellar surface. We develop a detailed geometric model for the emission columns above a carousel of sparks that is entirely calculated in the observer's inertial frame, and which is consistent with the well-understood rotational effects of aberration and retardation. We explore the observational consequences of the model, including (1) the appearance of the reconstructed beam pattern via the cartographic transform and (2) the morphology of drift bands and how they might evolve as a function of frequency. The model, which is implemented in the software package PSRGEOM, is applicable to a wide range of viewing geometries, and we illustrate its implications using PSRs B0809+74 and B2034+19 as examples. Some specific predictions are made with respect to the difference between subpulse evolution and microstructure evolution, which provides a way to further test our model.

arXiv commentAccepted for publication in ApJ

References in corpus (23)

• Topology and Polarisation of Subbeams Associated With Pulsar 0943+10's ``Drifting''-Subpulse Emission: I. Analysis of Arecibo 430- and 111-MHz Observations
• Coherent Emission Mechanisms in Astrophysical Plasmas
• Pulsar Magnetospheric Emission Mapping: Images and Implications of Polar-Cap Weather
• Understanding the radio emission geometry of PSR B0329+54
• Drifting Sub-Pulse Analysis Using the Two-Dimensional Fourier Transform
• On the methods of determining the radio emission geometry in pulsar magnetospheres
• Pulsar polarisation below 200 MHz: Average profiles and propagation effects
• Rotational sweepback of magnetic field lines in geometrical models of pulsar radio emission
• The Crab Pulsar at Centimeter Wavelengths II: Single Pulses
• Pulsar Radio Emission Altitude from Curvature Radiation
• Frequency dependence of the drifting subpulses of PSR B0031-07
• Low Frequency Observations of the Subpulse Drifter PSR J0034-0721 with the Murchison Widefield Array
• Frequency independent quenching of pulsed emission
• Vela, its X-ray nebula, and the polarization of pulsar radiation
• Differential Frequency-dependent Delay from the Pulsar Magnetosphere
• Pulsar "Drifting"-Subpulse Polarization: No Evidence for Systematic Polarization-Angle Rotations
• Inter-relationship between the Two Emission Cones of B1237+25
• B0943+10: low-frequency study of subpulse periodicity in the Bright mode with LOFAR
• Dynamics of Charged Particles in the Radio Emission Region of Pulsar Magnetosphere
• Variations of $P_2$ in subpulse drifting pulsars
• RRI-GBT Multi-Band Receiver: Motivation, Design & Development
• Rotational asymmetry of pulsar profiles
• Understanding the effects of geometry and rotation on pulsar intensity profiles