The Spitzer Space Telescope provides a unique view of the Universe at infrared wavelengths .
Improved sensitivity and angular resolution over previous missions enable detailed studies of astrophysical objects , both in imaging and spectroscopic modes .
Spitzer observations of active galactic nuclei can help shed light on the physical conditions of the central regions of these active glalaxies .

The nearby radio galaxy Cygnus A is one of the most luminous radio sources in the local Universe .
In addition to the high radio power , it is also very luminous in the infrared .
New Spitzer spectroscopy and photometry of Cygnus A is combined with data from the literature at radio and sub-mm wavelengths .
The resulting complication is modeled with a combination of : a synchrotron emitting jet , a burst of star formation , and emission from an AGN torus .

The infrared emission in Cyngus A shows contributions from all three processes and the models are able to reproduce the observed emission over almost 5 dex in frequency .
The bolometric AGN luminosity is found to be \sim 10 ^ { 45 } erg s ^ { -1 } , with a clumpy torus size of \sim 7 pc .
Evidence is seen for a break in the synchrotron spectrum in the mid-infrared .
The relevant component of the infrared emission suggests Cygnus A has a star formation rate of \sim 20 M _ { \odot } yr ^ { -1 } .
Even in the absence of the AGN , it would still be a luminous infrared source .