Abstract Details
| Name: Anuroop Dasgupta Affiliation: Universidad Diego Portales, Santiago, Chile Conference ID: ASI2025_43 Title : The Ophiuchus DIsk Survey Employing ALMA (ODISEA): Complete Size Distributions for the 100 Brightest Disks Across Multiplicity a Authors and Co-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 Abstract Type : Oral Abstract Category : Sun, Solar System, Exoplanets, and Astrobiology 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. |