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

Abstract

HR4796A hosts a well-studied debris disk with a long history due to its high fractional luminosity and favorable inclination lending itself well to both unresolved and resolved observations. We present new J- and K1-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 modelled 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 grain (DHS) models to the extracted functions. We find that while it is possible to describe 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.

Accepted for publication in AJ. 3 tables, 11 figures

References in corpus (14)

• The Gaia mission
• Monte Carlo radiative transfer in protoplanetary disks
• Probing for Exoplanets Hiding in Dusty Debris Disks: Disk Imaging, Characterization, and Exploration with HST/STIS Multi-Roll Coronagraphy
• Polarimetry with the Gemini Planet Imager: Methods, Performance at First Light, and the Circumstellar Ring around HR 4796A
• Near-infrared scattered light properties of the HR4796A dust ring: a measured scattering phase function from 13.6deg to 166.6deg
• STIS Imaging of the HR 4796A Circumstellar Debris Ring
• Speckle Suppression Through Dual Imaging Polarimetry, and a Ground-Based Image of the HR 4796A Circumstellar Disk
• Gemini Planet Imager Observational Calibrations I: Overview of the GPI Data Reduction Pipeline
• Gemini Planet Imager Observational Calibrations VIII: Characterization and Role of Satellite Spots
• Gap Clearing by Planets in a Collisional Debris Disk
• Gemini Planet Imager Observational Calibrations V: Astrometry and Distortion
• Optical polarized phase function of the HR\,4796A dust ring
• On the Morphology and Chemical Composition of the HR 4796A Debris Disk
• Infrared Spectroscopy of HR 4796A's Bright Outer Cometary Ring + Tenuous Inner Hot Dust Cloud

Cited by in corpus (15)

• How large are the monomers of dust aggregates in planet-forming disks?: Insights from quantitative optical and near-infrared polarimetry
• Retrieving Dust Grain Sizes from Photopolarimetry: An Experimental Approach
• The vertical structure of debris disks and the impact of gas
• Debris Disk Color with the Hubble Space Telescope
• Imaging exoplanets with coronagraphic instruments
• A Deep Polarimetric Study of the Asymmetrical Debris Disk HD 106906
• Morphology of the gas-rich debris disk around HD 121617 with SPHERE observations in polarized light
• A re-investigation of debris disc halos
• A model grid for the reflected light from transition disks
• Quadrant polarization parameters for the scattered light of circumstellar disks. Analysis of debris disk models and observations of HR 4796A
• Multiband polarimetric imaging of HD 34700 with SCExAO/CHARIS
• An HST/STIS View of Protoplanetary Disks in Upper Scorpius: Observations of Three Young M-Stars
• The Disks In Scorpius-Centaurus Survey (DISCS) I: Four Newly-Resolved Debris Disks in Polarized Intensity Light
• A Multiband Study of the HR 4796A Disk in the Optical Using MagAO-X
• Resolution and calibration effects in high contrast polarimetric imaging of circumstellar scattering regions