On the Submillimeter Opacity of Protoplanetary Disks
نویسنده
چکیده
Solid particles with the composition of interstellar dust and power-law size distribution dn/da ∝ a−p for a ≤ amax with amax & 3λ and 3 < p < 4 will have submm opacity spectral index β(λ) ≡ d lnκ/d ln ν ≈ (p−3)βism, where βism ≈ 1.7 is the opacity spectral index of interstellar dust material in the Rayleigh limit. For the power-law index p ≈ 3.5 that characterizes interstellar dust, and that appears likely for particles growing by agglomeration in protoplanetary disks, grain growth to sizes a & 3mm will result in β(1mm) . 1. Grain growth can naturally account for β ≈ 1 observed for protoplanetary disks, provided that amax & 3λ. Subject headings: planetary systems: protoplanetary disks dust, extinction, submillimeter
منابع مشابه
Submillimeter Constraints on Circumstellar Disk Structure
We present a high spatial resolution submillimeter continuum survey of 24 circumstellar disks in the Taurus-Auriga and Ophiuchus-Scorpius star formation regions using the SMA. In the context of a simple model, we use broadband spectral energy distributions and submillimeter visibilities to derive constraints on some basic parameters that describe the structure of these disks. For the typical di...
متن کاملThe Dust Properties of Eight Debris Disk Candidates as Determined by Submillimeter Photometry
The nature of far-infrared dust emission toward main sequence stars, whether interstellar or circumstellar, can be deduced from submillimeter photometry. We present JCMT/SCUBA flux measurements at 850μm toward 8 stars with large photospheric excesses at 60–100μm. 5 sources were detected at 3σ or greater significance and one was marginally detected at 2.5σ. The inferred dust masses and temperatu...
متن کاملSubmillimeter studies of circumstellar disks in Taurus and Orion
We highlight two recent studies of circumstellar disks in the Taurus and Orion star forming regions. Using the JCMT and CSO, we measure disk fluxes in Taurus over a wide range of submillimeter wavelengths and determine the frequency dependence of the dust opacity. We find clear evidence for a systematic change in its behavior with time, most readily explained by grain growth. Using the SMA, we ...
متن کاملSubmillimeter studies of circumstellar disks in Taurus and
We highlight two recent studies of circumstellar disks in the Tau-rus and Orion star forming regions. Using the JCMT and CSO, we measure disk fluxes in Taurus over a wide range of submillimeter wavelengths and determine the frequency dependence of the dust opacity. We find clear evidence for a systematic change in its behavior with time, most readily explained by grain growth. Using the SMA, we...
متن کاملA submillimeter view of protoplanetary dust disks
We present some results from our submillimeter single-dish and aperture synthesis imaging surveys of protoplanetary disks using the JCMT, CSO, and Submillimeter Array (SMA) on Mauna Kea, Hawaii. Employing a simple disk model, we simultaneously fit the spectral energy distributions and spatially resolved submillimeter continuum emission from our SMA survey to constrain disk structure properties,...
متن کامل