Herschel-SPIRE spectroscopy of G29.96-0.02: fitting the full SED

TL;DR

This study utilizes Herschel SPIRE FTS spectroscopy combined with other data to analyze the spectrum of G29.96-0.02, revealing detailed physical properties of the region including temperature, dust characteristics, and mass.

Contribution

It presents a comprehensive spectral analysis of G29.96-0.02 across multiple instruments, providing precise measurements of dust temperature, emissivity, and mass, which were not previously achievable.

Findings

Dust temperature of 80.3K with high accuracy.

Clump mass estimated at 1500 solar masses.

Bolometric luminosity of 4 million solar luminosities.

Abstract

We use the SPIRE Fourier-Transform Spectrometer (FTS) on-board the ESA Herschel Space Telescope to analyse the submillimetre spectrum of the Ultra-compact HII region G29.96-0.02. Spectral lines from species including 13CO, CO, [CI], and [NII] are detected. A sparse map of the [NII] emission shows at least one other HII region neighbouring the clump containing the UCHII. The FTS spectra are combined with ISO SWS and LWS spectra and fluxes from the literature to present a detailed spectrum of the source spanning three orders of magnitude in wavelength. The quality of the spectrum longwards of 100 {\mu}m allows us to fit a single temperature greybody with temperature 80.3\pm0.6K and dust emissivity index 1.73\pm0.02, an accuracy rarely obtained with previous instruments. We estimate a mass of 1500 Msol for the clump containing the HII region. The clump's bolometeric luminosity of 4 x 10^6 Lsol is comparable to, or slightly greater than, the known O-star powering the UCHII region.