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

We use the SPIRE Fourier-transform spectrometer (FTS) on-board the ESA Herschel Space Observatory 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 μm allows us to fit a single temperature greybody with temperature 80.3 ± 0.6 K and dust emissivity index 1.73± 0.02, an accuracy rarely obtained with previous instruments. We estimate a mass of 1500 M for the clump containing the HII region. The clump’s bolometeric luminosity of 4 × 10 L is comparable to, or slightly greater than, the known O-star powering the UCHII region.