Direct Imaging of the HD 35841 Debris Disk: A Polarized Dust Ring from Gemini Planet Imager and an Outer Halo from HST/STIS

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.

An Exo–Kuiper Belt with an Extended Halo around HD 191089 in Scattered Light

“…To study the dust properties, we assume the dust is made of different types of grains, each with a pure composition. We adopt the three compositions in Esposito et al (2018): the amorphous silicate dust (i.e., "astronomical silicates," denoted by "Si"; Draine & Lee 1984), amorphous carbonaceous dust (denoted by "C"; Rouleau & Martin 1991), and H 2 O-dominated ice described in Li & Greenberg (1998) to model the β Pic disk (denoted by "ice"). The size of the dust, a, follows a power-law distribution with index q, i.e.,…”

“…They are expected to be the result of the grinding down of larger dust (Wyatt 2008); however, the diversity in observables such as morphology and surface brightness suggests that they are shaped by a variety of mechanisms (e.g., Artymowicz & Clampin 1997;Stark et al 2014;Lee & Chiang 2016). Imaging studies of debris disks in scattered light use not only space-based instruments (e.g., the Space Telescope Imaging Spectrograph (STIS): Schneider et al 2009Schneider et al , 2014Schneider et al , 2016Schneider et al , 2018Konishi et al 2016;NICMOS: Soummer et al 2014;Choquet et al 2016Choquet et al , 2017Choquet et al , 2018 that offer the best telescope stability but also extreme adaptive optics-equipped ground-based instruments (e.g., GPI: Hung et al 2015;Kalas et al 2015;Millar-Blanchaer et al 2015Perrin et al 2015;Draper et al 2016;Esposito et al 2018;SPHERE: Boccaletti et al 2015;Lagrange et al 2016;Wahhaj et al 2016;Engler et al 2017;Feldt et al 2017;Matthews et al 2017;Milli et al 2017Milli et al , 2019Sissa et al 2018;Olofsson et al 2018) that provide the best angular resolution and probe closer-in regions of the disks.…”

“…In this paper, we focus on using scattered-light observations to understand one of these systems. In previous studies, the combination of space-and ground-based instruments has been implemented to study both protoplanetary (e.g., PDS 66: Wolff et al 2016) and debris (e.g., 49 Ceti: Choquet et al 2017;HD 35841: Esposito et al 2018) disks, and those observations are interpreted using radiative transfer codes (e.g., Augereau & Beust 2006;Milli et al 2015;Wolff et al 2017;Esposito et al 2018). We perform such an analysis for the debris disk surrounding HD191089 to study its specific properties via measurement and radiative transfer modeling in this paper.…”

Using Data Imputation for Signal Separation in High-contrast Imaging

“…However, forward modeling is currently only optimized for unresolved point sources (Marois et al 2010;Pueyo 2016). For resolved circumstellar disks, forward modeling needs assumptions on both morphology and flux (e.g., space-based: Choquet et al 2016Choquet et al , 2017Choquet et al , 2018ground-based: Follette et al 2017;Esposito et al 2018), which is model-dependent thus likely unable to capture the minute irregularly-shaped structures (e.g., the disks in Avenhaus et al 2018;Monnier et al 2019;Garufi et al 2020).…”

Linking studies of tiny meteoroids, zodiacal dust, cometary dust and circumstellar disks

“…Left. Phase curves of two debris disks around HD35841 (measured in the H-band with the Gemini Planet Imager,Esposito et al 2018) and HD191089 (measured in the optical with HST/ STIS and in the J band with HST/NICMOS,Ren et al 2019), presenting quite fair an agreement with those of 67P/C-G extracted from OSIRIS on 28 August 2015, soon after perihelion passage(Bertini et al 2017). Right.…”