1. Dual-wavelength ALMA observations of dust rings in protoplanetary disks
- Author
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Paola Pinilla, Giuseppe Lodato, Feng Long, Daniel Harsono, Nathan Hendler, David J. Wilner, Yao Liu, François Ménard, Ilaria Pascucci, Sean M. Andrews, Jeff Jennings, Gerrit van de Plas, Gregory J. Herczeg, Enrico Ragusa, Giovanni Dipierro, and Doug Johnstone
- Subjects
010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Submillimeter Array ,Planet ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,0105 earth and related environmental sciences ,Cosmic dust ,Physics ,Earth and Planetary Astrophysics (astro-ph.EP) ,Spectral index ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Wavelength ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Circumstellar dust ,Millimeter ,Astrophysics::Earth and Planetary Astrophysics ,Protoplanet ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We present new Atacama Large Millimeter/submillimeter Array (ALMA) observations for three protoplanetary disks in Taurus at 2.9\,mm and comparisons with previous 1.3\,mm data both at an angular resolution of $\sim0.''1$ (15\,au for the distance of Taurus). In the single-ring disk DS Tau, double-ring disk GO Tau, and multiple-ring disk DL Tau, the same rings are detected at both wavelengths, with radial locations spanning from 50 to 120\,au. To quantify the dust emission morphology, the observed visibilities are modeled with a parametric prescription for the radial intensity profile. The disk outer radii, taken as 95\% of the total flux encircled in the model intensity profiles, are consistent at both wavelengths for the three disks. Dust evolution models show that dust trapping in local pressure maxima in the outer disk could explain the observed patterns. Dust rings are mostly unresolved. The marginally resolved ring in DS Tau shows a tentatively narrower ring at the longer wavelength, an observational feature expected from efficient dust trapping. The spectral index ($\alpha_{\rm mm}$) increases outward and exhibits local minima that correspond to the peaks of dust rings, indicative of the changes in grain properties across the disks. The low optical depths ($\tau\sim$0.1--0.2 at 2.9\,mm and 0.2--0.4 at 1.3\,mm) in the dust rings suggest that grains in the rings may have grown to millimeter sizes. The ubiquitous dust rings in protoplanetary disks modify the overall dynamics and evolution of dust grains, likely paving the way towards the new generation of planet formation., Comment: accepted for publication in ApJ
- Published
- 2020