The X-ray Nature of Nucleus in Seyfert 2 Galaxy NGC 7590
  We present the result of the Chandra high-resolution observation of the
Seyfert~2 galaxy NGC 7590. This object was reported to show no X-ray absorption
in the low-spatial resolution ASCA data. The XMM observations show that the
X-ray emission of NGC 7590 is dominated by an off-nuclear ultra-luminous X-ray
source (ULX) and an extended emission from the host galaxy, and the nucleus is
rather weak, likely hosting a Compton-thick AGN. Our recent Chandra observation
of NGC 7590 enables to remove the X-ray contamination from the ULX and the
extended component effectively. The nuclear source remains undetected at
~4x10^{-15} erg/s/cm^-2 flux level. Although not detected, Chandra data gives a
2--10 keV flux upper limit of ~6.1x10^{-15} erg/s/cm^-2 (at 3 sigma level), a
factor of 3 less than the XMM value, strongly supporting the Compton-thick
nature of the nucleus. In addition, we detected five off-nuclear X-ray point
sources within the galaxy D25 ellipse, all with 2 -- 10 keV luminosity above
2x10^{38} erg/s (assuming the distance of NGC 7590). Particularly, the ULX
previously identified by ROSAT data was resolved by Chandra into two distinct
X-ray sources. Our analysis highlights the importance of high spatial
resolution images in discovering and studying ULXs.
