Probing the Nuclear and Circumnuclear Activity of NGC1365 in the
  Infrared
  We present new far-infrared (70-500micron) Herschel PACS and SPIRE imaging
observations as well as new mid-IR Gemini/T-ReCS imaging (8.7 and 18.3micron)
and spectroscopy of the inner Lindblad resonance (ILR) region (R<2.5kpc) of the
spiral galaxy NGC1365. We complemented these observations with archival Spitzer
imaging and spectral mapping observations. The ILR region of NGC1365 contains a
Seyfert 1.5 nucleus and a ring of star formation with an approximate diameter
of 2kpc. The strong star formation activity in the ring is resolved by the
Herschel/PACS imaging data, as well as by the Spitzer 24micron continuum
emission, [NeII]12.81micron line emission, and 6.2 and 11.3micron PAH emission.
The AGN is the brightest source in the central regions up to lambda~24micron,
but it becomes increasingly fainter in the far-infrared when compared to the
emission originating in the infrared clusters (or groups of them) located in
the ring. We modeled the AGN unresolved infrared emission with the CLUMPY torus
models and estimated that the AGN contributes only to a small fraction (~5%) of
the infrared emission produced in the inner ~5kpc. We fitted the non-AGN
24-500micron spectral energy distribution of the ILR region and found that the
dust temperatures and mass are similar to those of other nuclear and
circumnuclear starburst regions. Finally we showed that within the ILR region
of NGC1365 most of the on-going star formation activity is taking place in
dusty regions as probed by the 24micron emission.
