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

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; Metchev, Stanimir; Nielsen, Eric L.; Oppenheimer, Rebecca; Palmer, David W.; Patience, Jenny; Poyneer, Lisa A.; Pueyo, Laurent; Rajan, Abhijith; Rameau, Julien; Rantakyrö, Fredrik T.; Ruffio, Jean-Baptiste; Savransky, Dmitry; Schneider, Adam C.; Sivaramakrishnan, Anand; Song, Inseok; Soummer, Remi; Thomas, Sandrine; Wang, Jason J.; Ward-Duong, Kimberly; Wolff, Schuyler G.

doi:10.3847/1538-3881/ab91b1

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

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; Metchev, Stanimir; Nielsen, Eric L.; Oppenheimer, Rebecca; Palmer, David W.; Patience, Jenny; Poyneer, Lisa A.; Pueyo, Laurent; Rajan, Abhijith; Rameau, Julien; Rantakyrö, Fredrik T.; Ruffio, Jean-Baptiste; Savransky, Dmitry; Schneider, Adam C.; Sivaramakrishnan, Anand; Song, Inseok; Soummer, Remi; Thomas, Sandrine; Wang, Jason J.; Ward-Duong, Kimberly; Wolff, Schuyler G.

Authors

Pauline Arriaga

Michael P. Fitzgerald

Gaspard Duchêne

Paul Kalas

Maxwell A. Millar-Blanchaer

Marshall D. Perrin

Christine H. Chen

Johan Mazoyer

Mark Ammons

Vanessa P. Bailey

Trafis S. Barman

Joanna Bulger

Jeffrey K. Chilcote

Tara Cotten

Robert J. De Rosa

Rene Doyon

Thomas M. Esposito

Katherine B. Follette

Benjamin L. Gerard

Dr Stephen Goodsell stephen.goodsell@durham.ac.uk
Programme Manager

James R. Graham

Alexandra Z. Greenbaum

Pascale Hibon

Justin Hom

Li-Wei Hung

Patrick Ingraham

Quinn M. Konopacky

Bruce A. Macintosh

Jérôme Maire

Franck Marchis

Mark S. Marley

Christian Marois

Stanimir Metchev

Eric L. Nielsen

Rebecca Oppenheimer

David W. Palmer

Jenny Patience

Lisa A. Poyneer

Laurent Pueyo

Abhijith Rajan

Julien Rameau

Fredrik T. Rantakyrö

Jean-Baptiste Ruffio

Dmitry Savransky

Adam C. Schneider

Anand Sivaramakrishnan

Inseok Song

Remi Soummer

Sandrine Thomas

Jason J. Wang

Kimberly Ward-Duong

Schuyler G. Wolff

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.

Citation

Arriaga, P., Fitzgerald, M. P., Duchêne, G., Kalas, P., Millar-Blanchaer, M. A., Perrin, M. D., …Wolff, S. G. (2020). Multiband Polarimetric Imaging of HR 4796A with the Gemini Planet Imager. Astronomical Journal, 160(2), Article 79. https://doi.org/10.3847/1538-3881/ab91b1

Journal Article Type	Article
Acceptance Date	May 8, 2020
Online Publication Date	Jul 23, 2020
Publication Date	2020-08
Deposit Date	Aug 12, 2020
Publicly Available Date	Aug 12, 2020
Journal	Astronomical Journal
Print ISSN	0004-6256
Publisher	IOP Publishing
Peer Reviewed	Peer Reviewed
Volume	160
Issue	2
Article Number	79
DOI	https://doi.org/10.3847/1538-3881/ab91b1