2016A&A...586A..78B

We present new mid-infrared interferometric observations of the massive young stellar object IRAS 13481-6124, using VLTI/MIDI for spectrally-resolved, long-baseline measurements (projected baselines up to ∼120m) and GSO/T-ReCS for aperture-masking interferometry in five narrow-band filters (projected baselines of ∼1.8-6.4m) in the wavelength range of 7.5-13µm. We combine these measurements with previously-published interferometric observations in the K and N bands in order to assemble the largest collection of infrared interferometric observations for a massive YSO to date. Using a combination of geometric and radiative-transfer models, we confirm the detection at mid-infrared wavelengths of the disk previously inferred from near-infrared observations. We show that the outflow cavity is also detected at both near- and mid-infrared wavelengths, and in fact dominates the mid-infrared emission in terms of total flux. For the disk, we derive the inner radius (∼1.8mas or ∼6.5AU at 3.6kpc), temperature at the inner rim (∼1760K), inclination (∼48°) and position angle (∼107°). We determine that the mass of the disk cannot be constrained without high-resolution observations in the (sub-)millimeter regime or observations of the disk kinematics, and could be anywhere from ∼10^–3 to 20M_☉. Finally, we discuss the prospects of interpreting the spectral energy distributions of deeply-embedded massive YSOs, and warn against attempting to infer disk properties from the spectral energy distribution.