The X-ray jet and central structure of the active galaxy NGC 315

We report the Chandra detection of resolved X-ray emission of luminosity 3.5 x 10(40) erg s(-1) (0.4-4.5 keV) and power-law energy spectral index alpha= 1.5 +/- 0.7 from a roughly 10 arcsec length of the north-west radio jet in NGC 315. The X-ray emission is brightest at the base of the radio-bright region about 3 arcsec from the nucleus, and is consistent with a synchrotron origin. At a projected distance of 10 arcsec from the core, the jet is in approximate pressure balance with an external medium which is also detected through its X-ray emission and which has kT approximate to 0.6 +/- 0.1 keV, consistent with earlier ROSAT results. The high spatial resolution and sensitivity of Chandra separates nuclear unresolved emission from the extended thermal emission of the galaxy atmosphere with higher precision than possible with previous telescopes. We measure an X-ray luminosity of 5.3 x 10(41) erg s(-1) (0.4-4.5 keV) and a power-law energy index of alpha= 0.4 +/- 0.4 for the nuclear component.