An Inner Gaseous Disk around the Herbig Be Star MWC 147

TL;DR

This study uses high-resolution optical spectra to analyze the emission lines of the Herbig Be star MWC 147, revealing a structured circumstellar disk with gaseous and dusty components and estimating the inner disk's extent.

Contribution

It provides detailed spectroscopic evidence for a layered circumstellar disk structure around MWC 147, including the inner gaseous and outer dusty regions, with measurements of their spatial extents.

Findings

Emission lines originate from a rotating disk

Inner gaseous disk extends to at least 0.10 AU

Transition between gaseous and dusty disk at 2-3 AU

Abstract

We present high-spectral-resolution, optical spectra of the Herbig Be star MWC 147, in which we spectrally resolve several emission lines, including the [O I] lines at 6300 and 6363\deg. Their highly symmetric, double-peaked line profiles indicate that the emission originates in a rotating circumstellar disk. We deconvolve the Doppler-broadened [O I] emission lines to obtain a measure of emission as a function of distance from the central star. The resulting radial surface brightness profiles are in agreement with a disk structure consisting of a flat, inner, gaseous disk and a flared, outer, dust disk. The transition between these components at 2 to 3 AU corresponds to the estimated dust sublimation radius. The width of the double-peaked Mg II line at 4481\deg suggests that the inner disk extends to at least 0.10 AU, close to the corotation radius.