A Tale of Two Transition Disks: ALMA long-baseline observations of ISO-Oph 2 reveal two closely packed non-axisymmetric rings and a ~2 au cavity

ISO-Oph 2 is a wide-separation (240 au) binary system where the primary star harbors a massive(Mdust?40 M?) ring-like disk with a dust cavity?50 au in radius and the secondary hosts a muchlighter (Mdust?0.8 M?) disk.  As part of the high-resolution follow-up of the “Ophiuchus Disk Sur-vey Employing ALMA” (ODISEA) project, we present 1.3 mm continuum and 12CO molecular line observations of the system at 0.??02 (3 au) resolution.  We resolve the disk around the primary into two non-axisymmetric rings and find that the disk around the secondary is only?7 au across and also hasa dust cavity (r?2.2 au).  Based on the infrared flux ratio of the system and the M0 spectral type of the primary, we estimate the mass of the companion to be close to the brown dwarf limit.  Hence, we conclude that the ISO-Oph 2 system contains the largest and smallest cavities, the smallest measured disk size, and the resolved cavity around the lowest mass object (M??0.08 M) in Ophiuchus.  From the 12CO  data,  we  find  a  bridge  of  gas  connecting  both  disks.   While  the  morphology  of  the  rings around  the  primary  might  be  due  to  an  unseen  disturber  within  the  cavity,  we  speculate  that  the bridge might indicate an alternative scenario in which the secondary has recently flown by the primarystar causing the azimuthal asymmetries in its disk.  The ISO-Oph 2 system is therefore a remarkable laboratory to study disk evolution, planet formation, and companion-disk interactions.