Multi-wavelength Observations of MWC 297: Constraints on Disk Inclination and Mass Outflow

TL;DR

This study combines multi-wavelength observations to better understand the disk inclination, outflow, and luminosity of the young star MWC 297, revealing discrepancies with previous models and providing new estimates of its properties.

Contribution

It presents new multi-wavelength imaging and spectroscopic data, offering revised constraints on the disk inclination and mass outflow rate of MWC 297, challenging earlier interferometric results.

Findings

Disk inclination estimated at 55±5 degrees, higher than previous analyses.

Mass loss rate approximately 6.0±3.7×10^{-7} solar masses per year.

Total luminosity around 7900 solar luminosities, consistent with a B1.5V star.

Abstract

MWC 297 is a young, early-type star driving an ionized outflow and surrounded by warm, entrained dust. Previous analyses of near- and mid-IR interferometric images suggest that the emission at these wavelengths arises from a compact accretion disk with a moderate ($i < 40$ degrees) inclination. We have obtained 5-40 micron images of MWC 297 with FORCAST on SOFIA, as well as near-infrared spectra acquired with SpeX on the IRTF and radio data obtained with the VLA and BIMA, and supplemented these with archival data from Herschel/PACS and SPIRE. The FORCAST images, combined with the VLA data, indicate that the outflow lobes are aligned nearly north-south and are well separated. Simple geometrical modeling of the FORCAST images suggests that the disk driving the outflow has an inclination of $55\pm 5$ degrees, in disagreement with the results of the interferometric analyses. Analysis of the SpeX data, with a wind model, suggests the the mass loss rate is on the order of $6.0 \pm ^{3.7}_{1.7} \times 10^{-7} M_\odot ~\mathrm{yr}^{-1}$ and the extinction to the source is $A_V \sim 8.1 \pm^{2.5}_{1.5}$ mag. We have combined our data with values from the literature to generate the spectral energy distribution of the source from $0.35~ \mu$m to $6$ cm and estimate the total luminosity. We find the total luminosity to be about $7900 ~ L_\odot$, if we include emission from an extended region around the star, only slightly below that expected for a B1.5V star. The reddening must be produced by dust along the line of sight, but distant from the star.