Dust dissipation timescales in the intermediate and outer regions of protoplanetary disks

Abstract

Dust and gas in protoplanetary disks dissipate as central stars evolve. In order to estimate the dust dissipation timescales in the protoplanetary disks, we stacked the WISE 12, 22, and the AKARI 90 $\mu$m survey images of known T Tauri stars and derived the average fluxes, well below the survey flux limit in the 90 $\mu$m band. We classified 4,783 T Tauri stars into three age groups, which are young ($<$2 Myr), mid-age (2-6 Myr), and old ($>$6 Myr) groups, and stacked the WISE 12 and 22 and the AKARI 90 $\mu$m images in each group. The photometry of the stacked image shows the flux decay timescales of 1.4$\pm$0.2, 1.38$\pm$0.05, and 1.4${}_{-0.5}^{+0.6}$ Myr in the 12, 22, and 90 $\mu$m bands, respectively. In optically thin disks with one-solar luminosity central stars, the 12 and 22 $\mu$m fluxes are attributed to the emission from the intermediate ($\sim$ 1 au) region and the 90 $\mu$m flux corresponds to that from the outer ($\sim$ 10 au) region in the disk. We hence conclude the dust dissipation timescale is ${\tau }_{\mathrm{med},\mathrm{dust}}\sim$1.4 Myr in the intermediate disks and is ${\tau }_{\mathrm{outer},\mathrm{dust}}=$1.4${}_{-0.5}^{+0.6}$ Myr in the outer disks. The dust-dissipation time difference between the outer and intermediate disks is $\Delta {\tau }_{\mathrm{dust}}={\tau }_{\mathrm{outer},\mathrm{dust}}-{\tau }_{\mathrm{med},\mathrm{dust}}=0.0_{-0.5}^{+0.6}$ Myr, indicating that the dust in the intermediate and outer disks dissipates on almost the same timescale.

arXiv comment29 pages, 11 figures, 5 tables, accepted for publication in PASJ

References in corpus (29)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Gaia mission
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Protoplanetary Disks and Their Evolution
• The Infrared Astronomical Mission AKARI
• Gaia Data Release 2: Photometric content and validation
• Improving PARSEC models for very low mass stars
• New PARSEC evolutionary tracks of massive stars at low metallicity: testing canonical stellar evolution in nearby star forming dwarf galaxies
• Dust Properties of Protoplanetary Disks in the Taurus-Auriga Star Forming Region from Millimeter Wavelengths
• Debris Disk Evolution Around A Stars
• A Submillimeter View of Circumstellar Dust Disks in $\rho$ Ophiuchus
• The Far-Infrared Surveyor (FIS) for AKARI
• Protoplanetary disk lifetimes vs stellar mass and possible implications for giant planet populations
• Time-Evolution of Viscous Circumstellar Disks due to Photoevaporation by FUV, EUV and X-ray Radiation from the Central Star
• Steady-state evolution of debris disks around A stars
• Dust grain growth in rho-Ophiuchi protoplanetary disks
• Debris Disks: Seeing Dust, Thinking of Planetesimals and Planets
• Disk evolution in the solar neighborhood. I Disk frequencies from 1 to 100 Myr
• The Spitzer c2d Survey of Weak-Line T Tauri Stars. III. The Transition from Primordial Disks to Debris Disks
• The Dust Properties of Eight Debris Disk Candidates as Determined by Submillimeter Photometry
• Kuiper Belts Around Nearby Stars
• The Masses of Transition Circumstellar Disks: Observational Support for Photoevaporation Models
• Long-wavelength observations of debris discs around sun-like stars
• Possible Molecular Spiral Arms in the Protoplanetary Disk of AB Aur
• The Herschel DIGIT Survey of Weak-line T Tauri Stars: implications for disk evolution and dissipation
• Probing the Final Stages of Protoplanetary Disk Evolution with ALMA
• Mass and Temperature of the TWA 7 Debris Disk
• Environmental impacts on dust temperature of star-forming galaxies in the local Universe