Revealing Asymmetries in the HD 181327 Debris Disk: A Recent Massive Collision or ISM Warping

摘要: New multi-roll coronagraphic images of the HD 181327 debris disk obtained using Space Telescope Imaging Spectrograph (STIS) on board Hubble (HST) reveal ring in its entirety at high S/N and unprecedented spatial resolution. We present apply a new image processing routine to identify further remove quasi-static PSF-subtraction residuals quantify systematic uncertainties. also use iterative deprojection technique constrain true geometry aggressively any surface brightness asymmetries that can be explained without invoking dust density enhancements/deficits. The measured empirical scattering phase function for is more forward than previously thought not well-fit by Henyey-Greenstein function. varies with stellocentric distance, consistent expected radiation pressured-induced size segregation exterior belt. Within belt, contradicts unperturbed models, suggesting presence an unseen planet. radial profile flux degenerate radially-varying function; therefore estimates ring's width edge slope may highly uncertain. detect large scale disk, either recent catastrophic disruption body mass >1% Pluto, or warping due strong interactions interstellar medium (ISM).