Localised neutral hydrogen absorption towards the radio jet of Markarian 6

We present 0.15 arcsec (56 pc) resolution MERLIN observations of neutral hydrogen (HI) 21 cm absorption detected towards the arcsecond-scale radio jet of the Seyfert 1.5 galaxy Markarian 6. Absorption is detected only towards a bright, compact radio feature located, in projection, ~ 380 pc north of the likely location of the optical nucleus. Based on comparison with an archival HST image, we propose a geometry in which the HI absorption arises in a dust lane passing north of, but not covering, the optical nucleus, and the southern lobe of the jet is oriented on the near side of the inclined galaxian disk. We note that this result is contrary to previous models which place the extended narrow-line region on the near side of the disk.