Herschel evidence for disk flattening or gas depletion in transitional disks

Abstract

Transitional disks are protoplanetary disks characterized by reduced near- and mid-infrared emission with respect to full disks. This characteristic spectral energy distribution indicates the presence of an optically thin inner cavity within the dust disk believed to mark the disappearance of the primordial massive disk. We present new Herschel Space Observatory PACS spectra of [OI] 63 micron for 21 transitional disks. Our survey complements the larger Herschel GASPS program "Gas in Protoplanetary Systems" (Dent et al. 2013) by quadrupling the number of transitional disks observed with PACS at this wavelength. [OI] 63 micron traces material in the outer regions of the disk, beyond the inner cavity of most transitional disks. We find that transitional disks have [OI] 63 micron line luminosities two times fainter than their full disk counterparts. We self consistently determine various stellar properties (e.g. bolometric luminosity, FUV excess, etc.) and disk properties (e.g. disk dust mass, etc.) that could influence the [OI] 63 micron line luminosity and we find no correlations that can explain the lower [OI] 63 micron line luminosities in transitional disks. Using a grid of thermo-chemical protoplanetary disk models, we conclude that either transitional disks are less flared than full disks or they possess lower gas-to-dust ratios due to a depletion of gas mass. This result suggests that transitional disks are more evolved than their full disk counterparts, possibly even at large radii.

Accepted for publication in ApJ; 52 pages, 16 figures, 8 tables

References in corpus (17)

• Some Aspects of Measurement Error in Linear Regression of Astronomical Data
• Protoplanetary Disk Structures in Ophiuchus
• Photoevaporation of protoplanetary discs II: evolutionary models and observable properties
• UV excess measures of accretion onto young very low-mass stars and brown dwarfs
• The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)
• The Stellar Population of the Chamaeleon I Star-Forming Region
• On the Diversity of the Taurus Transitional Disks: UX Tau A & Lk Ca 15
• Demographics of Transition Objects
• The Disk Around CoKu Tau/4: Circumbinary, not Transitional
• LkH$\alpha$ 330: Evidence for dust clearing through resolved submillimeter imaging
• The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. XI. Lupus Observed With IRAC and MIPS
• Planetesimal formation via fragmentation in self-gravitating protoplanetary discs
• Pre-main sequence spectroscopic binaries suitable for VLTI observations
• Medium-separation binaries do not affect the first steps of planet formation
• High-resolution Spectroscopy of [Ne II] Emission from TW Hya
• Quiescent H2 Emission From Pre-Main Sequence Stars in Chamaeleon I
• A WFI survey in the Chamaeleon II dark cloud

Cited by in corpus (12)

• Molecules with ALMA at Planet-forming Scales (MAPS) I: Program Overview and Highlights
• Tracing Slow Winds from T Tauri Stars via Low Velocity Forbidden Line Emission
• Five steps in the evolution from protoplanetary to debris disk
• CSI 2264: Characterizing Young Stars in NGC 2264 with Short-Duration, Periodic Flux Dips in their Light Curves
• Probing stellar accretion with mid-infrared hydrogen lines
• XMM-Newton Survey of Local O VII Absorption Lines in the Spectra of Active Galactic Nuclei
• Large gaps and high accretion rates in photoevaporative transition disks with a dead zone
• Herschel-PACS observations of far-IR lines in YSOs I: [OI] and H2O at 63 microns
• A "Rosetta Stone" for protoplanetary disks: The synergy of multi-wavelength observations
• Brown dwarf disks with Herschel: Linking far-infrared and (sub)-mm fluxes
• The inner disk of RY Tau: evidence of stellar occultation by the disk atmosphere at the sublimation rim from K-band continuum interferometry
• An Incipient Debris Disk in the Chamaeleon I Cloud