Constraining the Earliest Circumstellar Disks and their Envelopes

TL;DR

This study uses interferometric data and advanced collapse models to constrain the properties of circumstellar disks and envelopes in four young stellar objects, aligning observations with theoretical predictions.

Contribution

It applies the Tassis & Mouschovias collapse model to interferometric data, providing new constraints on disk and envelope parameters in Class 0 objects.

Findings

Envelope emission is mostly resolved out, leaving residual emission from disks.

Disk masses are comparable to or smaller than those in T Tauri systems.

The collapse model fits the data well without age issues.

Abstract

Using interferometric data from BIMA observations, combined with detailed modeling in Fourier space of the physical structures predicted by models, we constrain the circumstellar envelope parameters for four Class 0 young stellar objects, as well as their embedded circumstellar disks. The envelopes of these objects are still undergoing collapse, and theoretical collapse models can be compared to the observations. Since it has been suggested in a previous study that both the Larson-Penston and Shu similarity solutions underestimate the age of the system, we adopt Tassis & Mouschovias' model of the collapse process, which includes all relevant magnetic fields effects. The results of the model fitting show a good consistency between theory and data; furthermore, no age problem exists since the Tassis & Mouschovias' model is age independent for the first 255 kyr. Although the majority of the continuum dust emission arises from the circumstellar envelopes, these objects have well known outflows, which suggest the presence of circumstellar disks. At the highest resolution, most of the large-scale envelope emission is resolved out by interferometry, but the small-scale residual emission remains, making it difficult to observe only the compact disk component. By modeling the emission of the envelope and subtracting it from the total emission, we constrain the disk masses in our four systems to be comparable to or smaller than the typical disk masses for T Tauri systems.