Multiband Polarimetric Imaging of HR 4796A With the Gemini Planet Imager

Authors

• Pauline Arriaga, University of California, Los Angeles
• Michael P. Fitzgerald, University of California, Los Angeles
• Gaspard Duchêne, University of California, Berkeley
• Paul Kalas, University of California, Berkeley
• Maxwell A. Millar-Blanchaer, Jet Propulsion Laboratory
• Marshall D. Perrin, Space Telescope Science Institute
• Christine H. Chen, Space Telescope Science Institute
• Johan Mazoyer, Jet Propulsion Laboratory
• Mark Ammons, Lawrence Livermore National Laboratory
• Vanessa P. Bailey, Jet Propulsion Laboratory
• Trafis S. Barman, The University of Arizona
• Joanna Bulger, National Institutes of Natural Sciences - National Astronomical Observatory of Japan
• Jeffrey K. Chilcote, University of Notre Dame
• Tara Cotten, University of Georgia
• Robert J. De Rosa, European Southern Observatory Santiago
• Rene Doyon, Institut de Recherche sur les Exoplanètes
• Thomas M. Esposito, University of California, Berkeley
• Katherine B. Follette, Amherst College
• Benjamin L. Gerard, University of Victoria
• Stephen Goodsell, Gemini ObservatorySouthern Operations Center
• James R. Graham, University of California, Berkeley
• Alexandra Z. Greenbaum, University of Michigan, Ann Arbor
• Pascale Hibon, European Southern Observatory Santiago
• Justin Hom, School of Earth and Space Exploration
• Li Wei Hung, US National Park Service
• Patrick Ingraham, Large Synoptic Survey Telescope
• Quinn M. Konopacky, Center for Astrophysics & Space Sciences
• Bruce A. MacIntosh, Stanford University
• Jérôme Maire, Center for Astrophysics & Space Sciences
• Franck Marchis, SETI Institute
• Mark S. Marley, NASA Ames Research Center
• Christian Marois, University of Victoria
• Kimberly Ward-Duong, Amherst CollegeFollow
• et al, Various Institutions

Document Type

Article

Publication Date

8-1-2020

Publication Title

Astronomical Journal

Abstract

HR4796A hosts a well-studied debris disk with a long history due to its high fractional luminosity and favorable inclination, which facilitate both unresolved and resolved observations. We present new J-and K 1-band images of the resolved debris disk HR4796A taken in the polarimetric mode of the Gemini Planet Imager (GPI). The polarized intensity features a strongly forward-scattered brightness distribution and is undetected at the far side of the disk. The total intensity is detected at all scattering angles and also exhibits a strong forward-scattering peak. We use a forward-modeled geometric disk in order to extract geometric parameters, polarized fraction, and total intensity scattering phase functions for these data as well as H-band data previously taken by GPI. We find the polarized phase function becomes increasingly more forward-scattering as wavelength increases. We fit Mie and distribution of hollow spheres (DHS) grain models to the extracted functions. We find that it is possible to generate a satisfactory model for the total intensity using a DHS model, but not with a Mie model. We find that no single grain population of DHS or Mie grains of arbitrary composition can simultaneously reproduce the polarized fraction and total intensity scattering phase functions, indicating the need for more sophisticated grain models.

Volume

160

Issue

2

DOI

https://doi.org/10.3847/1538-3881/ab91b1

ISSN

00046256

Rights

© 2020. The American Astronomical Society.

Version

Version of Record

Recommended Citation

Arriaga, Pauline; Fitzgerald, Michael P.; Duchêne, Gaspard; Kalas, Paul; Millar-Blanchaer, Maxwell A.; Perrin, Marshall D.; Chen, Christine H.; Mazoyer, Johan; Ammons, Mark; Bailey, Vanessa P.; Barman, Trafis S.; Bulger, Joanna; Chilcote, Jeffrey K.; Cotten, Tara; De Rosa, Robert J.; Doyon, Rene; Esposito, Thomas M.; Follette, Katherine B.; Gerard, Benjamin L.; Goodsell, Stephen; Graham, James R.; Greenbaum, Alexandra Z.; Hibon, Pascale; Hom, Justin; Hung, Li Wei; Ingraham, Patrick; Konopacky, Quinn M.; MacIntosh, Bruce A.; Maire, Jérôme; Marchis, Franck; Marley, Mark S.; Marois, Christian; Ward-Duong, Kimberly; and al, et, "Multiband Polarimetric Imaging of HR 4796A With the Gemini Planet Imager" (2020). Astronomy: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/ast_facpubs/105