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Title: Revealing asymmetries in the HD 181327 debris disk: A recent massive collision or interstellar medium warping

New multi-roll coronagraphic images of the HD 181327 debris disk obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope reveal the debris ring in its entirety at high signal-to-noise ratio and unprecedented spatial resolution. We present and apply a new multi-roll image processing routine to identify and further remove quasi-static point-spread function-subtraction residuals and quantify systematic uncertainties. We also use a new iterative image deprojection technique to constrain the true disk geometry and aggressively remove any surface brightness asymmetries that can be explained without invoking dust density enhancements/deficits. The measured empirical scattering phase function for the disk is more forward scattering than previously thought and is not well-fit by a Henyey-Greenstein function. The empirical scattering phase function varies with stellocentric distance, consistent with the expected radiation pressured-induced size segregation exterior to the belt. Within the belt, the empirical scattering phase function contradicts unperturbed debris ring models, suggesting the presence of an unseen planet. The radial profile of the flux density is degenerate with a radially varying scattering phase function; therefore estimates of the ring's true width and edge slope may be highly uncertain. We detect large scale asymmetries in the disk, consistent with either the recentmore » catastrophic disruption of a body with mass >1% the mass of Pluto, or disk warping due to strong interactions with the interstellar medium.« less
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6]
  1. NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States)
  2. Steward Observatory, The University of Arizona, Tucson, AZ 85721 (United States)
  3. Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015 (United States)
  4. Space Telescope Science Institute, Baltimore, MD 21218 (United States)
  5. Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States)
  6. Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States)
Publication Date:
OSTI Identifier:
22356469
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 789; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASYMMETRY; BRIGHTNESS; DENSITY; DISTANCE; FLUX DENSITY; IMAGE PROCESSING; IMAGES; INTERSTELLAR SPACE; MASS; PLUTO PLANET; RADIATION PRESSURE; SCATTERING; SIGNAL-TO-NOISE RATIO; SPACE; SPATIAL RESOLUTION; STELLAR CORONAE; STRONG INTERACTIONS; TELESCOPES