2001ApJ...557..180S

We report on a recent Chandra ACIS-S observation of the Circinus galaxy. These observations confirm that the nuclear spectrum results from reflection of a hard X-ray continuum by ``neutral'' matter. The nuclear X-ray emission is extended by ∼60 pc in the general direction of the optical ``ionization cone.'' An image in the Fe Kα line has been made and shows that this emission extends up to 200 pc from the nucleus. There is also large-scale X-ray emission both along and perpendicular to the galaxy disk. Thermal plasma models for this extended gas indicate temperatures kT∼0.6 keV, though cooler photoionized gas is also possible. The X-ray emission from gas in the disk is probably associated with the starburst ring of radius 150-250 pc. The gas extending ∼600 pc perpendicular to the disk is closely correlated with the high-excitation optical line emission. In addition to its soft X-ray emission, we tentatively detect a hard component from the gas above the plane; this hard emission may represent nuclear X-rays scattered into our line of sight by electrons in the outflowing wind. A total of 10 compact sources are found in the central kiloparsec of the galaxy. The most luminous has an X-ray luminosity of ≃10⁴⁰ ergs.s^–1 and seems to be an X-ray binary in the Circinus galaxy with a black hole mass exceeding 80 M_☉.