High resolution mid-Infrared imaging of dust disks structures around Herbig Ae stars with VISIR

TL;DR

This paper introduces a new observational mode for VISIR that achieves diffraction-limited mid-infrared imaging, enabling detailed resolution of dust disks around Herbig Ae stars, exemplified by the resolved disk around HD97048.

Contribution

The paper presents the BURST mode for VISIR, allowing diffraction-limited mid-IR imaging of circumstellar disks around Herbig Ae stars with unprecedented spatial resolution.

Findings

Resolved a 350 AU disk around HD97048 at 11.3 microns

Achieved 0.3 arcsec diffraction-limited resolution in mid-IR

Demonstrated the capability to study disk structures at 100 pc

Abstract

We present a new mode of observations with VISIR, the mid-InfraRed (mid-IR) imager and spectrometer on the VLT (ESO, Chile): the so-called BURST mode. This mode allows to reach the diffraction limit of the telescope. To illustrate results obtained with this mode, we discuss observations of disks around Herbig Ae stars. These stars are the more massive analogues of T Tauri stars and are believed to harbour circumstellar disks. The 10-20 microns atmospheric windows are well-suited to study the extended emission of these objects. With a 8 m class telescope, in fair seeing conditions, the observations are diffraction-limited at 10 microns and the spatial resolution could reach the diffraction limit of 0.3 arcsec. As a result, it is possible to resolve disks with a typical size of 100 AU around objects at a distance of 100 pc. We present here a significant example, HD97048, for which a flared disk of 350 AU is resolved at 11.3 microns (PAH band).