Interstellar scintillation and polarization of PSR B0656+14 in the Monogem ring
Yao, Jumei
High sensitivity interstellar scintillation and polarization observations made using the Five-hundred-meter Aperture Spherical radio Telescope (FAST) show that the shell of the Monogem ring and the local hot bubble dominate the scattering of PSR B0656+14 and the two-dimensional alignment of the pulsar spin axis and space velocity is far from near-perfect alignment. Based on the temporal
auto-correlation of the dynamic spectra on MJDs 59139 and 59183, we estimate the phase structure functions of the scattering plasma and find that they are inconsistent with a Kolmogorov spectrum for the scattering density fluctuations with showing both steeper and flatter spectra. The secondary spectrum computed from the dynamic spectrum on MJD 59183 shows two strong parabolic arcs, with the arc curvature implying that the scattering screens corresponding to the outer and inner arcs are located 52\pm7 pc and 103\pm13 pc from PSR B0656+14. The outer arc is consistent with the scattering occurring in the shell of the Monogem ring, thereby confirming the association, and the inner arc is approximately consistent with the scattering coming from shell of the local hot bubble. The position angle of spin axis derived from FAST pulse polarization observations is 19.8\pm0.9 deg from pulsar velocity, which is far from previously detected near-perfect alignment of 1\pm2 deg.