Probing dynamical processes in the planet forming region with dust mineralogy

Abstract

We present Herschel Space Observatory PACS spectra of GQ Lup, a protoplanetary disk in the Lupus star-forming region. Through SED fitting from 0.3μm to 1.3mm, we construct a self-consistent model of this system's temperature and density structures, finding that although it is 3 Myr old, its dust has not settled to the midplane substantially. The disk has a radial gradient in both the silicate dust composition and grain size, with large amorphous grains in the upper layers of the inner disk and an enhancement of submicron, crystalline grains in the outer disk. We detect an excess of emission in the Herschel PACS B2A band near 63μm and model it with a combination of {\sim}15 to 70μm crystalline water ice grains with a size distribution consistent with ice recondensation-enhanced grain growth and a mass fraction half of that of our solar system. The combination of crystalline water ice and silicates in the outer disk is suggestive of disk-wide heating events or planetesimal collisions. If confirmed, this would be the first detection of water ice by Herschel.

8 pages, 3 figures, 1 table, accepted to ApJ Letters

References in corpus (8)

• Detection of the Water Reservoir in a Forming Planetary System
• On the Diversity of the Taurus Transitional Disks: UX Tau A & Lk Ca 15
• Grain Retention and Formation of Planetesimals near the Snow Line in MRI-driven Turbulent Protoplanetary Disks
• Crystalline silicates and dust processing in the protoplanetary disks of the Taurus young cluster
• Line Emission from Gas in Optically Thick Dust Disks around Young Stars
• Coordinated Analyses of Presolar Grains in the Allan Hills 77307 and Queen Elizabeth Range 99177 Meteorites
• Spitzer Evidence for a Late Heavy Bombardment and the Formation of Urelites in η Corvi at ~1 Gyr
• A Method to Constrain the Size of the Protosolar Nebula

Cited by in corpus (19)

• Understanding the water emission in the mid- and far-IR from protoplanetary disks around T~Tauri stars
• An ALMA and MagAO Study of the Substellar Companion GQ Lup B
• Detections of trans-Neptunian ice in protoplanetary disks
• Candidate Water Vapor Lines to Locate the H${}_2$O Snowline through High-Dispersion Spectroscopic Observations I. The Case of a T Tauri Star
• The abundance and thermal history of water ice in the disk surrounding HD142527 from the DIGIT Herschel Key Program
• Dust continuum emission and the upper limit fluxes of sub-millimeter water lines of the protoplanetary disk around HD 163296 observed by ALMA
• A Herschel view of protoplanetary disks in the $\sigma$ Ori cluster
• Characterizing the protolunar disk of the accreting companion GQ Lupi B
• Low temperature optical properties of interstellar and circumstellar icy silicate grain analogues in the mid-infrared spectral region
• The water-ice feature in near-infrared disk-scattered light around HD 142527: Micron-sized icy grains lifted up to the disk surface?
• Constraining the detectability of water ice in debris disks
• Herschel PACS observations of 4-10 Myr old Classical T Tauri stars in Orion OB1
• Detection of Near-Infrared Water Ice at the Surface of the (pre)Transitional Disk of AB Aur: Informing Icy Grain Abundance, Composition, and Size
• Planetary influence on the young Sun's evolution: the solar neutrino probe
• Ices in planet-forming disks: Self-consistent ice opacities in disk models
• Diagnostic value of far-IR water ice features in T Tauri disks
• A transitional disk around an intermediate mass star in the sparse population of the Orion OB1 Association
• Absorption of crystalline water ice in the far infrared at different temperatures
• The formation of planetary systems with SPICA