Irregular Dust Features around Intermediate-mass Young Stars with GPI: Signs of Youth or Misaligned Disks?

Document Type

Article

Publication Date

12-27-2019

Publication Title

Astrophysical Journal

Volume

888

Issue

1

First page number:

1

Last page number:

21

Abstract

We are undertaking a large survey of over 30 disks using the Gemini Planet Imager (GPI) to see whether the observed dust structures match spectral energy distribution predictions and have any correlation with stellar properties. GPI can observe near-infrared light scattered from dust in circumstellar environments using high-resolution Polarimetric Differential Imaging with coronagraphy and adaptive optics. The data have been taken in the J and H bands over two years, with inner working angles of 0farcs08 and 0farcs11, respectively. Ahead of the release of the complete survey results, here we present five objects with extended and irregular dust structures within 2'' of the central star. These objects are FU Ori, MWC 789, HD 45677, Hen 3-365, and HD 139614. The observed structures are consistent with each object being a pre-main-sequence star with protoplanetary dust. The five objects' circumstellar environments could result from extreme youth and complex initial conditions, from asymmetric scattering patterns due to shadows cast by misaligned disks, or in some cases from interactions with companions. We see complex U phgr structures in most objects that could indicate multiple scattering or result from the illumination of companions. Specific key findings include the first high-contrast observation of MWC 789 revealing a newly discovered companion candidate and arc, and two faint companion candidates around Hen 3-365. These two objects should be observed further to confirm whether the companion candidates are comoving. Further observations and modeling are required to determine the causes of the structures.

Keywords

Near infrared astronomy; Protoplanetary disks; Polarimetry; Coronographic imaging; Circumstellar dust

Disciplines

Stars, Interstellar Medium and the Galaxy

Language

English

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