Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: ALMA Survey of Lupus Protoplanetary Disks II: Gas Disk Radii   We present ALMA Band 6 observations of a complete sample of protoplanetary
disks in the young (1-3 Myr) Lupus star-forming region, covering the 1.33 mm
continuum and the 12CO, 13CO, and C18O J=2-1 lines. The spatial resolution is
0.25 arcsec with a medium 3-sigma continuum sensitivity of 0.30 mJy,
corresponding to M_dust ~ 0.2 M_earth. We apply "Keplerian masking" to enhance
the signal-to-noise ratios of our 12CO zero-moment maps, enabling measurements
of gas disk radii for 22 Lupus disks; we find that gas disks are universally
larger than mm dust disks by a factor of two on average, likely due to a
combination of the optically thick gas emission as well as the growth and
inward drift of the dust. Using the gas disk radii, we calculate the
dimensionless viscosity parameter, alpha_visc, finding a broad distribution and
no correlations with other disk or stellar parameters, suggesting that viscous
processes have not yet established quasi-steady states in Lupus disks. By
combining our 1.33 mm continuum fluxes with our previous 890 micron continuum
observations, we also calculate the mm spectral index, alpha_mm, for 70 Lupus
disks; we find an anti-correlation between alpha_mm and mm flux for low-mass
disks (M_dust < 5), followed by a flattening as disks approach alpha_mm = 2,
which could indicate faster grain growth in higher-mass disks, but may also
reflect their larger optically thick components. In sum, this work demonstrates
the continuous stream of new insights into disk evolution and planet formation
that can be gleaned from unbiased ALMA disk surveys.

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The categories of this paper are: math
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The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
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The categories of this paper are: gr-qc
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The categories of this paper are: eess
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
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The categories of this paper are: hep-th
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The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin