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The nearby barred spiral galaxy NGC 1672 shows dramatic starburst activityand may also host a Seyfert 2 nucleus. We present new X-ray observations thatset constraints on starburst and Seyfert activity in NGC 1672. Two ROSAT HRIexposures, taken in 1992 and 1997, are used to investigate long-termvariability of the known X-ray sources and to search for new sources of X-rayemission. We find large-amplitude (about 69%) variability from X-3, one of theoff-nuclear sources located near an end of the galactic bar. X-3 has a peakobserved 0.2-2.0 keV luminosity of about 2.5 x 10^{39} erg/s, and it isprobably a luminous X-ray binary or young supernova remnant. We do not observevariability of the nuclear source X-1 or the strong off-nuclear source X-2. Ouranalyses also reveal two new off-nuclear sources, one of which is associatedwith a bright region along a spiral arm, and we find evidence for large-scalediffuse X-ray emission throughout part of the disk of NGC 1672. Furthermore, weuse ASCA data taken in 1995 to constrain the hard X-ray properties of NGC 1672.While the nuclear source X-1 is the dominant soft X-ray source in NGC 1672, wefind that the bulk of the 2-10 keV and 5-10 keV emission is spatiallycoincident with the off-nuclear source X-3, giving it an apparent 0.2-8 keVluminosity of about 6 x 10^{39} erg/s. A power-law plus Raymond-Smith modelprovides an acceptable fit to the full-band ASCA spectra. We do not find anyevidence for a luminous but absorbed nuclear X-ray source. If there is aluminous Seyfert 2 nucleus in NGC 1672, it must be obscured by a`Compton-thick' torus with a column density of > 2 x 10^{24} cm^{-2}.

New X-Ray Constraints on Starburst and Seyfert Activity in the Barred Spiral Galaxy NGC 1672