Physical properties of the Sh2-104 HII region as seen by Herschel
  Context: Sh2-104 is a Galactic H ii region with a bubble morphology, detected
at optical and radio wavelengths. It is considered the first observational
confirmation of the collect-and-collapse model of triggered star-formation.
Aims: We aim to analyze the dust and gas properties of the Sh2-104 region to
better constrain its effect on local future generations of stars. In addition,
we investigate the relationship between the dust emissivity index {\beta} and
the dust temperature, T_dust. Methods: Using Herschel PACS and SPIRE images at
100, 160, 250, 350 and 500 {\mu}m we determine T_dust and {\beta} throughout
Sh2-104, fitting the spectral energy distributions (SEDs) obtained from
aperture photometry. With the SPIRE Fourier transform spectrometer (FTS) we
obtained spectra at different positions in the Sh2-104 region. We detect
J-ladders of CO and 13CO, with which we derive the gas temperature and column
density. We also detect proxies of ionizing flux as the [NII] 3P1-3P0 and [CI]
3P2-3P1 transitions. Results: We find an average value of {\beta} ~ 1.5
throughout Sh2-104, as well as a T dust difference between the
photodissociation region (PDR, ~ 25 K) and the interior (~ 40 K) of the bubble.
We recover the anti-correlation between {\beta} and dust temperature reported
numerous times in the literature. The relative isotopologue abundances of CO
appear to be enhanced above the standard ISM values, but the obtained value is
very preliminary and is still affected by large uncertainties.
