SCExAO/CHARIS Near-infrared Scattered-light Imaging and Integral Field Spectropolarimetry of the AB Aurigae Protoplanetary System
Abstract We analyze near-infrared integral field spectropolarimetry of the AB Aurigae protoplanetary disk and protoplanet (AB Aur b), obtained with SCExAO/CHARIS in 22 wavelength channels covering the J , H , and K passbands ( λ 0 = 1.1–2.4 μ m) over angular separations of ρ ≈ 0.″13 to 1.″1 (∼20–175 au). Our images resolve spiral structures in the disk in each CHARIS channel. At the longest wavelengths, the data may reveal an extension of the western spiral seen in previous polarimetric data at ρ < 0.″3 out to larger distances clockwise from the protoplanet AB Aur b, coincident with the Atacama Large Millimeter/submillimeter Array–detected CO gas spiral. While AB Aur b is detectable in complementary total intensity data, it is a nondetection in polarized light at λ > 1.3 μ m. While the observed disk color is extremely red across JHK , the disk has a blue intrinsic scattering color consistent with small dust grains. The disk’s polarization spectrum is redder than AB Aur b’s total intensity spectrum. The polarization fraction peaks at ∼0.6 along the major disk axis. Radiative transfer modeling of the CHARIS data shows that small, porous dust grains with a porosity of p = 0.6–0.8 better reproduce the scattered-light appearance of the disk than more compact spheres ( p = 0.3), especially the polarization fraction. This work demonstrates the utility of integral field spectropolarimetry to characterize structures in protoplanetary disks and elucidate the properties of the disks’ dust.
Authors
- Timothy D. Brandt (ORCID: https://orcid.org/0000-0003-2630-8073)
- N. Jeremy Kasdin (ORCID: https://orcid.org/0000-0002-6963-7486)
- Tyler D. Groff (ORCID: https://orcid.org/0000-0001-5978-3247)
- C. A. Grady (ORCID: https://orcid.org/0000-0001-5440-1879)
- Nemanja Jovanović (ORCID: https://orcid.org/0000-0001-5213-6207)
- Danielle Bovie (ORCID: https://orcid.org/0000-0001-7967-9922)
- Jun Hashimoto (ORCID: https://orcid.org/0000-0002-3053-3575)
- Frantz Martinache (ORCID: https://orcid.org/0000-0003-1180-4138)
- Thayne Currie (ORCID: https://orcid.org/0000-0002-7405-3119)
- Olivier Guyon (ORCID: https://orcid.org/0000-0002-1097-9908)
- Julien Lozi (ORCID: https://orcid.org/0000-0002-3047-1845)
- Minghan Chen (ORCID: https://orcid.org/0000-0001-8892-4045)
- Kellen Lawson (ORCID: https://orcid.org/0000-0002-6964-8732)
- Jeffrey Chilcote (ORCID: https://orcid.org/0000-0001-6305-7272)
- Mona El Morsy (ORCID: https://orcid.org/0000-0001-9441-7656)
- Sébastien Vievard (ORCID: https://orcid.org/0000-0003-4018-2569)
- Motohide Tamura (ORCID: https://orcid.org/0000-0002-6510-0681)
- Nour Skaf (ORCID: https://orcid.org/0000-0002-9372-5056)
- Michael L. Sitko (ORCID: https://orcid.org/0000-0003-1799-1755)
- Tomoyuki Kudo (ORCID: https://orcid.org/0000-0002-9294-1793)
- Vincent Déo (ORCID: https://orcid.org/0000-0003-4514-7906)
- Taichi Uyama (ORCID: https://orcid.org/0000-0002-6879-3030)
- Miles Lucas (ORCID: https://orcid.org/0000-0001-6341-310X)
- Erica Dykes (ORCID: https://orcid.org/0009-0002-8645-1736)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2024-12-01
- DOI
- https://doi.org/10.3847/1538-4357/ad8ba0
- Citations
- 2
- Primary Topic
- Astrophysics and Star Formation Studies
- Type
- article
- Field-Weighted Citation Impact
- 0.66
Funders
- National Aeronautics and Space Administration