Disk masses in the Orion Molecular Cloud-2: distinguishing time and environment

Abstract

Context. The mass evolution of protoplanetary disks is driven by both internal processes, and external factors, such as photoevaporation. Disentangling these two effects, however, has remained difficult. Aims. We measure the dust masses of a sample of 132 disks in the Orion Molecular Cloud (OMC)-2 region, and compare them to (i) externally photoevaporated disks in the Trapezium cluster, and (ii) disks in nearby low-mass star forming regions (SFRs). This allows us to test if initial disk properties are the same in high-and low-mass SFRs, and enables a direct measurement of the effect of external photoevaporation on disks. Methods. A ∼ 20 × 4 mosaic of 3 mm continuum observations from the Atacama Large Millimeter/submillimeter Array (ALMA) was used to measure the fluxes of 132 disks and 35 protostars > 0.5 pc away from the Trapezium. We identify and characterize a sample of 34 point sources not included in the Spitzer catalog on which the sample is based. Results. Of the disks, 37 (28%) are detected, with masses ranging from 7 − 270 M ⊕ . The detection rate for protostars is higher, at 69%. Disks near the Trapezium are found to be less massive by a factor 0.18 +0.18 −0.11 , implying a mass loss rate of 8 × 10 −8 M yr −1 . Conclusions. Our observations allow us to distinguish the impact of time and environment on disk evolution in a single SFR. The disk mass distribution in OMC-2 is statistically indistinguishable from that in nearby low-mass SFRs, like Lupus and Taurus. We conclude that age is the main factor determining the evolution of these disks. This result is robust with respect to assumptions of dust temperature, sample incompleteness and biases. The difference between the OMC-2 and Trapezium cluster samples is consistent with mass loss driven by far-ultraviolet radiation near the Trapezium. Together, this implies that in isolation, disk formation and evolution proceed similarly, regardless of cloud mass.

Herschel Observations of Protoplanetary Disks in Lynds 1641*

“…less dense region and with a lower radiation background (Hsu et al 2012;Pillitteri et al 2013;Megeath et al 2016). We find that L1641 has a dust mass distribution that lies at higher masses than the young ONC (Eisner et al 2018) and older σ Ori (Ansdell et al 2017), similar to that of OMC1 (Eisner et al 2016), and slightly lower masses than OMC2 (van Terwisga et al 2019). This is further evidence that the dust mass distributions depend on the age of the region, evolutionary state, and exposure to external photoevaporation and stellar densities.…”

“…find disks with low masses and truncated radii in the ONC whilevan Terwisga et al (2019) find that the OMC2 region, north of the ONC with lower stellar densities, has disk populations that are indistinguishable from low-mass systems like Taurus and Lupus. L1641 is estimated to have over 1600 Class II and Class III objects, comparable in size to the ONC but in a…”

Stellar clustering shapes the architecture of planetary systems

“…The properties of protoplanetary disks (within which planets are born) are correlated with the properties of the star formation environment 7 , 8 , 82 – 85 . In regions of high stellar density, protoplanetary disks can be truncated by encounters with nearby stars 86 – 88 .…”

Protoplanetary disk masses in NGC 2024: Evidence for two populations

“…In this article, we take the distance d to NGC 2024 to be 414 pc (Menten et al 2007;Bailer-Jones et al 2018). To facilitate the comparison of this sample of disks to other ALMA surveys of disks in star-forming regions (e.g., Ansdell et al 2016;van Terwisga et al 2019), we use standard assumptions for the values of the other parameters in Eq. 1: (Andrews & Williams 2005), and κ ν = κ 0 (ν/ν 0 ) β with β = 1 and κ 1000 GHz = 10 cm 2 g −1 (Beckwith et al 1990).…”

“…The left panel shows three well-studied, nearby, low-mass regions, where external photoevaporation is not expected to be a major factor in disk evolution. In contrast, the panel on the right shows Class II disk masses in different environments in Orion A and B: the Trapezium and σ Orionis, where external photoevaporation has been shown to affect disk masses (Mann et al 2014;Ansdell et al 2017;Eisner et al 2018), and the OMC-2 region, which is to the north of the Trapezium and where no evidence for external photoevaporation has been found (van Terwisga et al 2019). In this comparison, we cannot take into account possible differences in stellar masses, even though these may be significant, as discussed in Sect.…”