Dust in active galactic nuclei. Mid-infrared T-ReCS/Gemini spectra using
  the new RedCan pipeline
  The unified model of active galactic nuclei (AGN) claims that the properties
of AGN depend on the viewing angle of the observer with respect to a toroidal
distribution of dust surrounding the nucleus. Both the mid-infrared (MIR)
attenuation and continuum luminosity are expected to be related to dust
associated with the torus. Therefore, isolating the nuclear component is
essential to study the MIR emission of AGN. We have compiled all the T-ReCS
spectra (Gemini observatory) available in the N-band for 22 AGN: 5 Type-1 and
17 Type-2 AGN. The high angular resolution of the T-ReCs spectra allows us to
probe physical regions of 57 pc (median). We have used a novel pipeline called
RedCan capable of producing flux- and wavelength-calibrated spectra for the
CanariCam (GTC) and T-ReCS (Gemini) instruments. We have measured the
fine-structure [SIV] at 10.5 microns and the PAH at 11.3 microns line strengths
together with the silicate absorption/emission features. We have also compiled
Spitzer/IRS spectra to understand how spatial resolution influences the
results. The 11.3 microns PAH feature is only clearly detected in the nuclear
spectra of two AGN, while it is more common in the Spitzer data. For those two
objects the AGN emission in NGC7130 accounts for more than 80% of the MIR
continuum at 12 microns while in the case of NGC1808 the AGN is not dominating
the MIR emission. This is confirmed by the correlation between the MIR and
X-ray continuum luminosities. The [SIV] emission line at 10.5 microns, which is
believed to originate in the narrow line region, is detected in most AGN. We
have found an enhancement of the optical depth at 9.7 microns in the
high-angular resolution data for higher values of NH. Clumpy torus models
reproduce the observed values only if the host-galaxy properties are taken into
account.
