A multi-instrument and multi-wavelength high angular resolution study of MWC614: quantum heated particles inside the disk cavity

TL;DR

This study uses high-resolution multi-instrument, multi-wavelength observations to analyze the disk structure of MWC 614, revealing an inclined disk with a large cavity, extended hot dust emission, and potential quantum heated particles inside the cavity.

Contribution

It provides the first comprehensive high-angular-resolution multi-wavelength analysis of MWC 614, highlighting the presence of quantum heated dust particles inside the disk cavity.

Findings

Inclined disk with a ~10 au cavity confirmed.

Extended near-infrared emission indicating high dust temperature (~1800 K).

Possible quantum heated dust grains inside the cavity.

Abstract

High angular resolution observations of young stellar objects are required to study the inner astronomical units of protoplanetary disks in which the majority of planets form. As they evolve, gaps open up in the inner disk regions and the disks are fully dispersed within ~10 Myrs. MWC 614 is a pre-transitional object with a ~10au radius gap. We present a set of high angular resolution observations of this object including SPHERE/ZIMPOL polarimetric and coronagraphic images in the visible, KECK/NIRC2 near-infrared aperture masking observations and VLTI (AMBER, MIDI, and PIONIER) and CHARA (CLASSIC and CLIMB) long-baseline interferometry at infrared wavelengths. We find that all the observations are compatible with an inclined disk (i ~55deg at a position angle of ~20-30deg). The mid-infrared dataset confirms the disk inner rim to be at 12.3+/-0.4 au from the central star. We determined an upper mass limit of 0.34 Msun for a companion inside the cavity. Within the cavity, the near-infrared emission, usually associated with the dust sublimation region, is unusually extended (~10 au, 30 times larger than the theoretical sublimation radius) and indicates a high dust temperature (T~1800 K). As a possible result of companion-induced dust segregation, quantum heated dust grains could explain the extended near-infrared emission with this high temperature. Our observations confirm the peculiar state of this object where the inner disk has already been accreted onto the star exposing small particles inside the cavity to direct stellar radiation.