We present the first high-resolution , X-ray image of the circumnuclear regions of the Seyfert 1 galaxy NGC 3516 , using the Chandra X-ray Observatory ( CXO ) .
All three of the CXO observations reported were performed with one of the two grating assemblies in place , and here we restrict our analysis to undispersed photons ( i.e .
those detected in the zeroth-order ) .
A previously-unknown X-ray source is detected \sim 6 arcsec ( 1.1 h _ { 75 } ^ { -1 } kpc ) NNE of the nucleus ( position angle \sim 29 degrees ) which we designate CXOU 110648.1+723412 .
Its spectrum can be characterized as a power law with a photon index \Gamma \sim 1.8–2.6 , or as thermal emission with a temperature kT \sim 0.7–3 keV .
Assuming a location within NGC 3516 , isotropic emission implies a luminosity L \sim 2–8 \times 10 ^ { 39 } h _ { 75 } ^ { -2 } { erg s ^ { -1 } } in the 0.4–2 keV band .
If due to a single point source , the object is super-Eddington for a 1.4 M _ { \odot } neutron star .
However , multiple sources or a small , extended source can not be excluded using the current data .
Large-scale extended X-ray emission is also detected out to \sim 10 arcsec ( \sim 1.7 h _ { 75 } ^ { -1 } kpc ) from the nucleus to the NE and SW , and is approximately aligned with the morphologies of the radio emission and extended narrow emission line region ( ENLR ) .
The mean luminosity of this emission is 1–5 \times 10 ^ { 37 } h _ { 75 } ^ { -2 } { erg s ^ { -1 } arcsec ^ { -2 } } , in the 0.4–2 keV band .
Unfortunately the current data can not usefully constrain its spectrum .
These results are consistent with earlier suggestions of circumnuclear X-ray emission in NGC 3516 .
If the extended emission is due to scattering of the nuclear X-ray continuum , then the pressure in the X-ray emitting gas is at least two orders of magnitude too small to provide the confining medium for the ENLR clouds .