Remnant gas in evolved circumstellar disks: Herschel PACS observations of 10-100 Myr old disk systems
arXiv:1206.1044 · doi:10.1088/0004-637X/755/1/8
Abstract
We present Herschel PACS spectroscopy of the [OI] 63 micron gas-line for three circumstellar disk systems showing signs of significant disk evolution and/or planet formation: HR 8799, HD 377 and RX J1852.3-3700. [OI] is undetected toward HR 8799 and HD 377 with 3 sigma upper limits of 6.8 x 10^-18 W m^-2 and 9.9 x 10^-18 W m^-2 respectively. We find an [OI] detection for RX J1852.3-3700 at 12.3 +- 1.8 x 10^-18 W m^-2. We use thermo-chemical disk models to model the gas emission, using constraints on the [OI] 63 micron, and ancillary data to derive gas mass upper limits and constrain gas-to-dust ratios. For HD 377 and HR 8799, we find 3 sigma upper limits on the gas mass of 0.1-20 Mearth. For RX J1852.3-3700, we find two distinct disk scenarios that could explain the detection of [OI] 63 micron and CO(2-1) upper limits reported from the literature: (i) a large disk with gas co-located with the dust (16-500 AU), resulting in a large tenuous disk with ~16 Mearth of gas, or (ii) an optically thick gas disk, truncated at ~70 AU, with a gas mass of 150 Mearth. We discuss the implications of these results for the formation and evolution of planets in these three systems.
Accepted for publication in ApJ, 8 pages ApJ style (incl. references), 2 figures, 4 tables
References in corpus (18)
- Direct Imaging of Multiple Planets Orbiting the Star HR 8799
- New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey
- Photoevaporation of protoplanetary discs II: evolutionary models and observable properties
- Toward a Deterministic Model of Planetary Formation V. Accumulation Near the Ice Line
- Spitzer IRS Spectroscopy of IRAS-Discovered Debris Disks
- Dust dynamics during protoplanetary disc clearing
- The Complete Census of 70-um-Bright Debris Disks within the FEPS (Formation and Evolution of Planetary Systems) Spitzer Legacy Survey of Sun-like Stars
- Two Earth-sized planets orbiting Kepler-20
- Line Emission from Gas in Optically Thick Dust Disks around Young Stars
- Formation and Evolution of Planetary Systems: Upper Limits to the Gas Mass in Disks Around Sun-like Stars
- Survival of icy grains in debris discs. The role of photosputtering
- The Formation of Ice Giants in a Packed Oligarchy: Instability and Aftermath
- The Dust Properties of Eight Debris Disk Candidates as Determined by Submillimeter Photometry
- Gas modelling in the disc of HD 163296
- A Survey for Massive Giant Planets in Debris Disks with Evacuated Inner Cavities
- Long-wavelength observations of debris discs around sun-like stars
- Formation of Narrow Dust Rings in Circumstellar Debris Disks
- On the Nature of Small Planets around the Coolest Kepler Stars