| Authors: | Anuroop Dasgupta 1,2
Lucas A. Cieza 1,2
Camilo González-Ruilova 3,2
Trisha Bhowmik 1,2
Prachi Chavan 1,2
Grace Batalla-Falcon 1
Gregory Herczeg 4,5
Dary Ruiz-Rodriguez 6
Jonathan P. Williams 7
Anibal Sierra 8
Simon Casassus 9,2
Octavio Guilera 10
Sebastian Pérez 11,12,2
Santiago Orcajo 13
P.H. Nogueira 2
A.S. Hales 6,2
J.M. Miley 2
Fernando R. Rannou 14
Alice Zurlo 1,2
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| Authors Affiliation: | 1. Instituto de Estudios Astrofisicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile.
2.Millennium Nucleus on Young Exoplanets and their Moons (YEMS), Chile.
3.Universidad de Santiago de Chile, Av. Libertador Bernardo O'Higgins 3363, Estación Central, Santiago.
4. Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, China.
5. Department of Astronomy, Peking University, Beijing 100871, China.
6.National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475, United States of America.
7. Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA.
8. Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK.
9.Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile.
10.Instituto de Astrofísica de La Plata (IALP), CCT La Plata-CONICET-UNLP, Paseo del Bosque s/n, La Plata, Argentina.
11. Center for Interdisciplinary Research in Astrophysics and Space Exploration (CIRAS), Universidad de Santiago, Chile.
12. Millennium Nucleus on Young Exoplanets and their Moons (YEMS), Chile.
13. Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, 1900 La Plata, Argentina.
14. Departamento de Ingeniería Informática, Universidad de Santiago de Chile, Av. Libertador Bernardo O'Higgins 3363, Estación Central, Santiago |
| Abstract: | Submitted to ApJ.
The size of a protoplanetary disk is one of its most fundamental properties. However, most disks remain unresolved, even in the closest star-forming regions (distance approximately 140-200 parsecs). In this study, we present the complete continuum size distribution for about 100 of the brightest protoplanetary disks (with dust masses greater than approximately 2 Earth masses) in the Ophiuchus molecular cloud, obtained through ALMA Band-8 (410 GHz) observations at a resolution of 0.05 to 0.15 arcseconds (equivalent to 7 to 21 astronomical units). We measure the Half Width at Half Maximum (HWHM) of the dust continuum for each disk, and the radius encircling 68% of the flux (denoted as R68%R68%) using Frank profiles. This results in the largest flux-limited sample of resolved disks in any star-forming region. We find that the full distribution follows a log-normal pattern with an HWHM logarithmic mean of 1.1 (equivalent to 13 astronomical units) and a standard deviation of 0.46 (equivalent to a factor of 2.9). Stars in close binary systems (separation less than 200 astronomical units) have significantly smaller radii, with a logarithmic mean of 0.7 (equivalent to 5 astronomical units), which indicates very efficient radial drift in the outer regions of the disk, as predicted by models of binary systems. The disk size distribution for young embedded objects (SED Class I and Flat Spectrum, with age less than approximately 1 million years) is indistinguishable from that of more evolved Class II objects (with age of a few million years), suggesting that pressure bumps must be present at early stages of disk evolution to halt the migration of millimeter-sized particles at astronomical unit scales.
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