A STEEPER THAN LINEAR DISK MASS-STELLAR MASS SCALING RELATION

• Published in: The Astrophysical journal Vol. 831; no. 2; pp. 125 - 143
• Main Authors: Pascucci, I., Testi, L., Herczeg, G. J., Long, F., Manara, C. F., Hendler, N., Mulders, G. D., Krijt, S., Ciesla, F., Henning, Th, Mohanty, S., Drabek-Maunder, E., Apai, D., Sz cs, L., Sacco, G., Olofsson, J.
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 10.11.2016; IOP Publishing
• Subjects: Astronomi, astrofysik och kosmologi; Astronomy, Astrophysics and Cosmology; Astrophysics; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; brown dwarfs; COSMIC DUST; Dust; Dust emission; DWARF STARS; EMISSION; Emissions; FLUX DENSITY; FORECASTING; FRAGMENTATION; Grain growth; LUMINOSITY; MAIN SEQUENCE STARS; MASS; Planet formation; PLANETS; Power law; protoplanetary disks; PROTOPLANETS; SPATIAL RESOLUTION; Star formation; stars: pre-main sequence; Stellar luminosity; Stellar mass; submillimeter: planetary systems
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.3847/0004-637X/831/2/125

ABSTRACT The disk mass is among the most important input parameter for every planet formation model to determine the number and masses of the planets that can form. We present an ALMA 887 m survey of the disk population around objects from ∼2 to 0.03 M in the nearby ∼2 Myr old Chamaeleon I star-forming region. We detect thermal dust emission from 66 out of 93 disks, spatially resolve 34 of them, and identify two disks with large dust cavities of about 45 au in radius. Assuming isothermal and optically thin emission, we convert the 887 m flux densities into dust disk masses, hereafter Mdust. We find that the relation is steeper than linear and of the form Mdust ∝ (M*)1.3-1.9, where the range in the power-law index reflects two extremes of the possible relation between the average dust temperature and stellar luminosity. By reanalyzing all millimeter data available for nearby regions in a self-consistent way, we show that the 1-3 Myr old regions of Taurus, Lupus, and Chamaeleon I share the same relation, while the 10 Myr old Upper Sco association has a steeper relation. Theoretical models of grain growth, drift, and fragmentation reproduce this trend and suggest that disks are in the fragmentation-limited regime. In this regime millimeter grains will be located closer in around lower-mass stars, a prediction that can be tested with deeper and higher spatial resolution ALMA observations.