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Resolving scattering disks with ground-space VLBI

Ground-Space VLBI observations of pulsars with baselines up to ~20 Earth diameters show a surprising view of visibility (delay-fringe rate plot, or delay-Doppler in “secondary spectra”). At low & medium baselines, besides the main peak in the origin it contains a number of needle-like spikes at non-zero delays. At long baselines, the main peak is absent, it decays completely into a cloud of spikes within the delay range corresponding to the “scattering disk” diameter. Such uncommon structure is created because a scattered image of pulsar is essentially a number of coherent copies of a single original source which are distributed within the “scattering disk” area. Ground — Space baselines with Radioastron are favorable for studying interstellar scattering from nearby pulsars with a small scattering angle and a small number of scattered rays, hence it becomes possible to give an adequate interpretation of observational data.

 

Cody Hall, AB 107

Vladimir Soglasnov (Lebedev Physical Institute)

October 18, 2017
14:00 - 15:00