LkH$\alpha$ 330: Evidence for dust clearing through resolved submillimeter imaging

Abstract

Mid-infrared spectrophotometric observations have revealed a small sub-class of circumstellar disks with spectral energy distributions (SEDs) suggestive of large inner gaps with low dust content. However, such data provide only an indirect and model dependent method of finding central holes. We present here the direct characterization of a 40 AU radius inner gap in the disk around LkHa 330 through 340 GHz (880 micron) dust continuum imaging with the Submillimeter Array (SMA). This large gap is fully resolved by the SMA observations and mostly empty of dust with less than 1.3 x 10^-6 M_solar of solid particles inside of 40 AU. Gas (as traced by accretion markers and CO M-band emission) is still present in the inner disk and the outer edge of the gap rises steeply -- features in better agreement with the underlying cause being gravitational perturbation than a more gradual process such as grain growth. Importantly, the good agreement of the spatially resolved data and spectrophometry-based model lends confidence to current interpretations of SEDs with significant dust emission deficits as arising from disks with inner gaps or holes. Further SED-based searches can therefore be expected to yield numerous additional candidates that can be examined at high spatial resolution.

11 pages, 3 figures, accepted to ApJL

References in corpus (12)

• Coagulation, fragmentation and radial motion of solid particles in protoplanetary disks
• Protoplanetary Disk Structures in Ophiuchus
• Photoevaporation of protoplanetary discs II: evolutionary models and observable properties
• Accretion in the Rho-Oph pre-main sequence stars
• Dust filtration at gap edges: Implications for the spectral energy distributions of discs with embedded planets
• Spectro-astrometric imaging of molecular gas within protoplanetary disk gaps
• The Disk Around CoKu Tau/4: Circumbinary, not Transitional
• An Inner Hole in the Disk around TW Hydrae Resolved in 7 Millimeter Dust Emission
• A VLT/NACO Survey for Triple and Quadruple Systems among Visual Pre-Main Sequence Binaries
• Probing the Dust and Gas in the Transitional Disk of CS Cha with Spitzer
• Mid-Infrared Spectroscopy of Disks around Classical T Tauri Stars
• The Structure of Protoplanetary Disks Surrounding Three Young Intermediate Mass Stars. I. Resolving the disk rotation in the [OI] 6300 Åline