Direct Imaging of the HD 35841 Debris Disk: A Polarized Dust Ring from Gemini Planet Imager and an Outer Halo from HST/STIS
Duchêne, Gaspard; Esposito, Thomas M.; Oppenheimer, Rebecca; Rice, Malena; Chen, Christine H.; Kalas, Paul; Arriaga, Pauline; De Rosa, Robert J.; Fitzgerald, Michael P.; Macintosh, Bruce; Mazoyer, Johan; Metchev, Stanimir; Millar-Blanchaer, Maxwell A.; Nielsen, Eric L.; Perrin, Marshall D.; Pueyo, Laurent; Rantakyrö, Fredrik T.; Barman, Travis; Graham, James R.; Song, Inseok; Marchis, Franck; Schneider, Adam C.; Ansdell, Megan; Wolff, Schuyler; Sivaramakrishnan, Anand; Marois, Christian; Chilcote, Jeffrey; Ward-Duong, Kimberly; Wang, Jason J.; Bailey, Vanessa P.; Ammons, S. Mark; Choquet, Élodie; Ren, Bin; Chiang, Eugene; Follette, Katherine B.; Sebastián Bruzzone, Juan; Bulger, Joanna; Cotten, Tara; Doyon, Rene; Goodsell, Stephen J.; Greenbaum, Alexandra Z.; Hibon, Pascale; Hung, Li-Wei; Ingraham, Patrick; Konopacky, Quinn; Larkin, James E.; Maire, Jérôme; Palmer, David; Patience, Jennifer; Poyneer, Lisa; Rajan, Abhijith; Rameau, Julien; Ryan, Dominic; Savransky, Dmitry; Soummer, Rémi; Thomas, Sandrine; Wallace, J. Kent; Wiktorowicz, Sloane
United States, France, Canada, Chile, Netherlands
Abstract
We present new high resolution imaging of a light-scattering dust ring and halo around the young star HD 35841. Using spectroscopic and polarimetric data from the Gemini Planet Imager in H-band (1.6 μm), we detect the highly inclined (i = 85°) ring of debris down to a projected separation of ∼12 au (∼0.″12) for the first time. Optical imaging from HST/STIS shows a smooth dust halo extending outward from the ring to >140 au (>1.″4). We measure the ring’s scattering phase function and polarization fraction over scattering angles of 22°-125°, showing a preference for forward scattering and a polarization fraction that peaks at ∼30% near the ansae. Modeling of the scattered-light disk indicates that the ring spans radii of ∼60-220 au, has a vertical thickness similar to that of other resolved dust rings, and contains grains as small as 1.5 μm in diameter. These models also suggest the grains have a low porosity, are more likely to consist of carbon than astrosilicates, and contain significant water ice. The halo has a surface brightness profile consistent with that expected from grains pushed by radiation pressure from the main ring onto highly eccentric but still bound orbits. We also briefly investigate arrangements of a possible inner disk component implied by our spectral energy distribution models, and speculate about the limitations of Mie theory for doing detailed analyses of debris disk dust populations.