Gas and dust in the inner disk of the Herbig Ae star MWC 758

TL;DR

This study uses interferometric observations to analyze the origin of near-infrared emission in the inner disk of the Herbig Ae star MWC 758, revealing a dusty inner rim and hot gaseous accretion disk.

Contribution

It provides the first detailed interferometric analysis distinguishing dust and gas contributions in the inner disk of MWC 758.

Findings

K band emission from dusty inner rim at 0.4 AU

H band emission mainly from within 0.1 AU

Evidence for hot gaseous accretion disk in H band

Abstract

In this Letter we investigate the origin of the near-infrared emission of the Herbig Ae star MWC 758 on sub-astronomical unit (AU) scales using spectrally dispersed low resolution (R=35) AMBER/VLTI interferometric observations both in the H ($1.7 \mu$m) and K ($2.2 \mu$m) bands. We find that the K band visibilities and closure phases are consistent with the presence of a dusty disk inner rim located at the dust evaporation distance (0.4 AU) while the bulk of the H band emission arises within 0.1 AU from the central star. Comparing the observational results with theoretical model predictions, we suggest that the H band emission is dominated by an hot gaseous accretion disk.