Scintillation Properties of PSR B1133+16 Measured with Very Long Baseline Interferometry

TL;DR

This study uses VLBI to analyze scintillation arcs of pulsar PSR B1133+16, revealing anisotropic scattering screens and measuring their orientations and distances with high precision, enhancing understanding of the interstellar medium.

Contribution

It provides the first detailed VLBI measurements of scintillation arcs for PSR B1133+16, accurately determining the locations and orientations of scattering screens.

Findings

Three scintillation arcs identified, consistent with anisotropic scattering screens.

Measured distances to screens at approximately 140, 180, and 250 parsecs.

Screens near the Local Bubble wall are associated with the nearer scattering structures.

Abstract

The scintillation of pulsars reveals small-scale structure of the interstellar medium. A powerful technique for characterizing the scintillating structures (screens) combines analysis of scintillation arcs and very long baseline interferometry (VLBI). We present the results of a VLBI analysis of the scintillation arcs of PSR B1133+16 from simultaneous observations with Arecibo, VLA, Jodrell Bank, Effelsberg, and Westerbork. Three arcs appear in the data set, all of which appear consistent with being the result of very anisotropic scattering screens. We are able to measure their orientations on the sky, down to uncertainties of $5\arcdeg$ for the two stronger screens, and measure distances, of $140\pm30$, $180\pm20$, and $250\pm30{\rm\,pc}$, consistent with, but substantially more precise than what was inferred previously from annual modulation patterns in the scintillation. Comparing with the differential dust extinction with distance in this direction, the two nearer screens appear associated with the wall of the Local Bubble.