The Chandra HRC View of the Sub-arcsecond Structures in the Nuclear Region of NGC 1068

We have obtained a high spatial resolution X-ray image of the nucleus of NGC 1068 using the High Resolution Camera (HRC-I) on board the Chandra X-ray Observatory, which provides an unprecedented view of the innermost 1 arcsecond radius region of this galaxy. The HRC image resolves the narrow line region into X-ray emission clumps matching bright emission-line clouds in the HST [OIII]5007 images and allows comparison with sub-arcsecond scale radio jet for the first time. Two distinct X-ray knots are revealed at 1.3-1.4 arcsecond northeast and southwest of the nucleus. Based on the combined X-ray, [OIII], and radio continuum morphology, we identify the locations of intense radio jet-cloud interaction. The [OIII] to soft X-ray ratios show that some of these clouds are strongly affected by shock heating, whereas in other locations the jet simply thrusts through with no signs of strong interaction. This is further strengthened by the presence of a kT~1 keV collisionally ionized component in the ACIS spectrum of a shock heated cloud (HST-G). We estimate that the kinematic luminosity of the jet-driven shocks is 6x10^{38} erg/s, a negligible fraction (10^{-4}) of the estimated total jet power.

💡 Research Summary

The authors present a sub‑arcsecond X‑ray view of the nucleus of the nearby Seyfert 2 galaxy NGC 1068 obtained with the Chandra High Resolution Camera (HRC‑I). The HRC image, with a point‑spread function of ≈0.13″ (FWHM), resolves the inner 1″ (≈70 pc) radius region into a series of discrete X‑ray clumps that correspond closely to bright emission‑line clouds seen in HST