Mid‐Infrared and CO Observations of the Infrared/X‐Ray Luminous Seyfert 1 Galaxy NGC 985: The Making or Breaking of a ULIRG?

We describe ISO and BIMA observations of the z=0.04 Seyfert 1 ring galaxyNGC985 which suggest close parallels with some quasar host galaxies. NGC985contains two closely spaced nuclei embedded in an R$^{1/4}$--law stellar bulgeand an outer ring, evidence of an ongoing merger. The system contains\~1.8x10^{10}Msolar of highly disturbed molecular gas which lies in anasymmetric bar-like structure with the peak in observed CO column densitiessignificantly offset from the compact double nucleus. In contrast to this, theISO observations show strong dust emission centered on the AGN, located in oneof the two nuclei. Fainter CO, MIR, and radio continuum emission provide aglimpse of the complexities of star formation in the outer ring. An analysis ofthe kinematics of the main CO emission reveal evidence for two dynamicallydistinct molecular components within NGC985. The first is a set of isolatedsuper-giant molecular clouds (SGMCs) which are concentrated within 9-10kpc ofthe active nucleus. Although randomly distributed about the center, the cloudsmay form part of a clumpy highly-disturbed disk which may be either justforming around double-nucleus (the making of a ULIRG), or alternatively may bein the process of being disrupted-perhaps as a result of a powerful nuclearoutflow (the breaking of a ULIRG). A second major concentration of CO liesoffset from the double-nucleus in a dynamically coherent ridge of emission inwhich powerful star formation is occurring. We tentatively associate COemission with two out of six UV absorption-lines seen in the blue wing of thevery broad Lyman alpha emission. Such an association would imply a complexinter-relationship between the nuclear CO cloud population in collidingsystems, and AGN-driven winds.