Proplyds and Massive Disks in the Orion Nebula Cluster Imaged with CARMA and SMA

Abstract

We imaged a 2 ′ × 2 ′ region of the Orion Nebula cluster in 1.3 mm wavelength continuum emission with the recently commissioned Combined Array for Research in Millimeter Astronomy (CARMA) and with the Submillimeter Array 2 Here and throughout the text, "massive disks" refer to disks with mass comparable to or greater than 0.01 M ⊙ , the lower range of estimates for the minimum-mass solar nebula.

A Vla Survey for Faint Compact Radio Sources in the Orion Nebula Cluster

“…Disk mass measurements are facilitated at shorter wavelengths, of 1.3 mm or 870 μm, where the ratio of dust emission to free-free emission is expected to be more favorable. Even here, however, free-free emission can contribute significantly to the observed brightness of the sources (e.g., Eisner et al 2008;Mann & Williams 2009, 2010Mann et al 2014).…”

“…Disk mass measurements are typically made by observing dust continuum emission at long wavelengths, where the emission is optically thin and probes the entirety of the disk (e.g., Beckwith et al 1990). Toward this end, a host of millimeter interferometric surveys of the ONC have previously been carried out (e.g., Mundy et al 1995;Bally et al 1998b; Williams et al 2005;Eisner & Carpenter 2006;Eisner et al 2008;Mann & Williams 2009, 2010Mann et al 2014).…”

“…Free-free emission has a flat spectrum ( n µ n -F 0.1 ) when optically thin, which is expected to be true at millimeter and centimeter wavelengths (e.g., Eisner et al 2008;Mann & Williams 2009, 2010Mann et al 2014). Optically thick freefree emission can span a range of spectral indices, but the emission usually only becomes optically thick at wavelengths longer than ∼10 cm (e.g., Eisner et al 2008).…”

Disk Masses for Embedded Class I Protostars in the Taurus Molecular Cloud

“…Over the past few decades, there have been numerous studies of nearby star-forming regions at millimeter wavelengths with the aim of measuring disk masses for large samples of disks, and this work has been accelerated in recent years by the power of ALMA to quickly survey large numbers of sources (e.g., Beckwith et al 1990;Osterloh & Beckwith 1995;Dutrey et al 1996;Andrews & Williams 2005, 2007Eisner et al 2008Eisner et al , 2016Mann & Williams 2010;Andrews et al 2013;Mann et al 2014;Ansdell et al 2016Ansdell et al , 2017Barenfeld et al 2016;Pascucci et al 2016). These surveys have tended to target the population of Class II protostar disks because they are no longer embedded in an envelope, and so estimates of their disk masses are more straightforward.…”

“…Class II disks are the easiest to study because, without a protostellar envelope, the entirety of the submillimeter flux can be attributed to disk emission. In the past decade there has been a large effort, particularly with interferometers like the Combined Array for Research in Millimeter-wave Astronomy (CARMA), the SMA, and now ALMA, toward measuring Class II disk masses (Andrews & Williams 2005, 2007Eisner et al 2008;Mann & Williams 2010;Mann et al 2014;Ansdell et al 2016Ansdell et al , 2017Barenfeld et al 2016;Pascucci et al 2016). These studies typically find that the majority of these disks fall well below the  -M 0.01 0.1 needed to form planetary systems like our own (e.g., Weidenschilling 1977;Desch 2007).…”