Fast moving pulsars as probes of interstellar medium

Abstract

Pulsars moving through ISM produce bow shocks detected in hydrogen H$\alpha$ line emission. The morphology of the bow shock nebulae allows one to probe the properties of ISM on scales $\sim 0.01$ pc and smaller. We performed 2D RMHD modeling of the pulsar bow shock and simulated the corresponding H$\alpha$ emission morphology. We find that even a mild spatial inhomogeneity of ISM density, $\delta \rho /\rho \sim 1$, leads to significant variations of the shape of the shock seen in H$\alpha$ line emission. We successfully reproduce the morphology of the Guitar Nebula. We infer quasi-periodic density variations in the warm component of ISM with a characteristic length of $\sim 0.1$~pc. Structures of this scale might be also responsible for the formation of the fine features seen at the forward shock of Tycho SNR in X-rays. Formation of such short periodic density structures in the warm component of ISM is puzzling, and bow-shock nebulae provide unique probes to study this phenomenon.

12 pages, 7 figures, accepted MNRAS

References in corpus (11)

• PLUTO: a Numerical Code for Computational Astrophysics
• Three-dimensional Features of the Outer Heliosphere Due to Coupling between the Interstellar and Heliospheric Magnetic Field. V. The Bow Wave, Heliospheric Boundary Layer, Instabilities, and Magnetic Reconnection
• Pulsar Wind Nebulae Created by Fast-Moving Pulsars
• Pulsar-wind nebulae and magnetar outflows: observations at radio, X-ray, and gamma-ray wavelengths
• On the X-ray feature associated with the Guitar Nebula
• X-ray emission properties of the old pulsar PSR B2224+65
• Three-dimensional hydrodynamic simulations of asymmetric pulsar wind bow shocks
• X-ray Stripes in Tycho's Supernova Remant: Synchrotron Footprints of a Nonlinear Cosmic Ray-driven Instability
• How the power spectrum of dust continuum images may hide the presence of a characteristic filament width
• Bow-shock Pulsar Wind Nebulae Passing Through Density Discontinuities
• Inner-shell ionization, radiative losses and thermal conductivity in young SNRs

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