  Soft X-ray spectroscopy of Seyfert 2 galaxies offers perhaps the best method
to probe the possible connection between AGN activity and star formation.
Obscuration of powerful radiation from the inferred nucleus allows for detailed
study of circumnuclear emission regions. And soft X-ray spectroscopy of these
regions allows for robust discrimination between warm gas radiatively driven by
the AGN and hot collisionally-driven gas possibly associated with star
formation. A simple model of a (bi-)cone of gas photoionized and photoexcited
by a nuclear power-law continuum is sufficient to explain the soft X-ray
spectra of all Seyfert 2 galaxies so far observed by the XMM-Newton and Chandra
satellites. An upper limit of around 10 percent to an additional hot,
collisionally-driven gas contribution to the soft X-ray regime appears to hold
for five different Seyfert 2 galaxies, placing interesting constraints on
circumnuclear star formation.
