Mid-infrared interferometry of massive young stellar objects

TL;DR

This study uses mid-infrared interferometry with VLTI to resolve the inner structures of massive young stellar objects at scales of 20-50 AU, providing new insights into their formation regions.

Contribution

First application of VLTI MIDI interferometry to resolve inner structures of massive YSOs at unprecedented scales, improving understanding beyond SED-based models.

Findings

Resolved structures of 10 massive YSOs at 20-50 AU scales.

Demonstrated MIDI data's ability to clarify YSO structural ambiguities.

Modeling results for two objects support the observational conclusions.

Abstract

The very inner structure of massive young stellar objects (YSOs) is difficult to trace. With conventional observational methods we identify structures still several hundreds of AU in size. However, the (proto-)stellar growth takes place at the innermost regions (<100 AU) where the actual mass transfer onto the forming high-mass star occurs. We present results from our programme toward massive YSOs at the VLTI, utilising the two-element interferometer MIDI. To date, we observed 10 well-known massive YSOs down to scales of 20 mas (typically corresponding to 20 - 40 AU for our targets) in the 8-13 micron region. We clearly resolve these objects which results in low visibilities and sizes in the order of 30-50 mas. For two objects, we show results of our modelling. We demonstrate that the MIDI data can reveal decisive structure information for massive YSOs. They are often pivotal in order to resolve ambiguities still immanent in model parameters derived from sole SED fitting.