2008/03/05 by Alice K. Harding, Julie V. Stern, Jaroslaw Dyks +1 · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Pulsars and Gravitational Waves Research #Radio Astronomy Observations and Technology #astro-ph
paper · pdf · doi:10.1086/588037
35 pages, 7 figures, accepted for publication in Astrophysical Journal
arxiv created 2008/03/05 · openalex publication_date 2008/06/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We present results of a 3D model of optical-to-γ-ray emission from the slot gap accelerator of a rotation-powered pulsar. Primary electrons accelerating to high altitudes in the unscreened electric field of the slot gap reach radiation reaction limited Lorentz factors of ~2 × 10 7 , while electron-positron pairs from lower altitude cascades flow along field lines interior to the slot gap. The curvature, synchrotron, and inverse Compton radiation of both primary electrons and pairs produce a broad spectrum of emission from infrared to GeV energies. Both primaries and pairs undergo cyclotron resonant absorption of radio photons, allowing them to maintain significant pitch angles. Synchrotron radiation from pairs with a power-law energy spectrum from γ = 10 2 to 10 5 , dominate the spectrum up to ~10 MeV. Synchrotron and curvature radiation of primaries dominates from 10 MeV up to a few GeV. We examine the energy-dependent pulse profiles and phase-resolved spectra for parameters of the Crab pulsar as a function of magnetic inclination α and viewing angle ζ, comparing to broadband data. In most cases, the pulse profiles are dominated by caustics on trailing field lines. We also explore the relation of the high-energy and the radio profiles, as well as the possibility of caustic formation in the radio cone emission. We find that the Crab pulsar profiles and spectrum can be reasonably well reproduced by a model with α = 45° and ζ ∼ 100° or 80°. This model predicts that the slot gap emission below 200 MeV will exhibit correlations in time and phase with the radio emission.