Unveiling the traits of massive young stellar objects through a multi-scale survey

TL;DR

This study uses a consistent multi-scale observational and modeling approach to characterize massive young stellar objects, revealing similarities in envelope structures but diversity in disk features, and correlating luminosity with disk inner holes.

Contribution

It introduces a uniform multi-scale analysis method applied to a sample of MYSOs, enabling direct comparison and revealing common envelope features and variable disk structures.

Findings

MYSOs are well modeled by disk-outflow-envelope geometries similar to low-mass protostars.

Envelope and cavity characteristics are consistent across the sample.

A correlation exists between central luminosity and the size of the inner disk hole.

Abstract

The rarity and deeply embedded nature of stars with masses larger than 8 solar masses has limited our understanding of their formation. Previous work has shown that complementing spectral energy distributions with interferometric and imaging data can probe the circumstellar environments of massive young stellar objects (MYSOs) well. However, complex studies of single objects often use different approaches in their analysis. Therefore the results of these studies cannot be directly compared. This work aims to obtain the physical characteristics of a sample of MYSOs at ~0.01" scales, at 0.1" scales, and as a whole, which enables us to compare the characteristics of the sources. We apply the same multi-scale method and analysis to a sample of MYSOs. High-resolution interferometric data, near-diffraction-limited imaging data, and a multi-wavelength spectral energy distribution are combined. By fitting simulated observables derived from 2.5D radiative transfer models of disk-outflow-envelope systems to our observations, the properties of the MYSOs are constrained. We find that the observables of all the MYSOs can be reproduced by models with disk-outflow-envelope geometries, analogous to the Class I geometry associated with low-mass protostars. The characteristics of the envelopes and the cavities within them are very similar across our sample. On the other hand, the disks seem to differ between the objects, in particular with regards to what we interpret as evidence of complex structures and inner holes. This is comparable to the morphologies observed for low-mass young stellar objects. A strong correlation is found between the luminosity of the central MYSO and the size of the transition disk-like inner hole for the MYSOs, implying that photoevaporation or the presence of binary companions may be the cause.