Integral-field spectroscopy of the young high-mass star IRAS13481-6124

TL;DR

This study uses AO-assisted K-band IFU spectroscopy to analyze the young high-mass star IRAS13481-6124, revealing a rotating ionized disk aligned with the outflow and providing insights into its kinematic properties.

Contribution

First detailed AO-assisted spectroscopic analysis of IRAS13481-6124, showing non-Keplerian rotation and confirming the star as the outflow driver.

Findings

Detected a 1 AU photo-center shift aligned with outflow

Found a rigid rotation pattern in the innermost disk

Observed absence of H2 emission from the source

Abstract

We present results of AO-assisted K-band IFU spectroscopy of the massive young star IRAS13481-6124 performed with ESO's VLT/SINFONI instrument. Our spectro-astrometric analysis of the Br{\gamma} line revealed a photo-center shift with respect to the adjacent continuum of \sim1 AU at a distance of 3.1 kpc. The position angle of this shift matches with that of the outflow which confirms that the massive star is indeed the driving source. Furthermore, a velocity gradient along the major disk axis was found which hints at the rotational sense of the ionized region, and thus of the disk as well. The gradient is not consistent with Keplerian motion but points to rigid rotation of the innermost disk. Notably, emission of H_2 is absent from source while both shocked and fluorescent H_2 emission are observed in its immediate surroundings.