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

Abstract

ISO-Oph 2 is a wide-separation (240 au) binary system where the primary star harbors a massive (M${}_{dust}$ $\sim$40 M${}_{\oplus }$) ring-like disk with a dust cavity $\sim$50 au in radius and the secondary hosts a much lighter (M${}_{dust}$ $\sim$0.8 M${}_{\oplus }$) disk. As part of the high-resolution follow-up of the "Ophiuchus Disk Survey Employing ALMA" (ODISEA) project, we present 1.3 mm continuum and ${}^{12}$CO 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 $\sim$7 au across and also has a dust cavity (r $\sim$2.2 au). Based on the infrared flux ratio of the system and the M0 spectral type of the primary, we estimate the mass of the companion to be close to the brown dwarf limit. Hence, we conclude that the ISO-Oph 2 system contains the largest and smallest cavities, the smallest measured disk size, and the resolved cavity around the lowest mass object (M${}_{\star }$ $\sim$0.08 M${}_{\odot }$) in Ophiuchus. From the ${}^{12}$CO 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 primary star 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.

arXiv comment10 pages, 4 figures, 1 table

References in corpus (40)

• Gaia Data Release 2. Summary of the contents and survey properties
• First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
• The Disk Substructures at High Angular Resolution Project (DSHARP): I. Motivation, Sample, Calibration, and Overview
• Models of Stars, Brown Dwarfs and Exoplanets
• A Major Asymmetric Dust Trap in a Transition Disk
• Ringed Substructure and a Gap at 1 AU in the Nearest Protoplanetary Disk
• A Steeper than Linear Disk Mass-Stellar Mass Scaling Relation
• Observations of gas flows inside a protoplanetary gap
• An ALMA Survey of Protoplanetary Disks in the $\sigma$ Orionis Cluster
• ALMA Observations of Circumstellar Disks in the Upper Scorpius OB Association
• Compact Disks in a High Resolution ALMA Survey of Dust Structures in the Taurus Molecular Cloud
• The Ophiuchus DIsc Survey Employing ALMA (ODISEA) - I : project description and continuum images at 28 au resolution
• Circumbinary, not transitional: On the spiral arms, cavity, shadows, fast radial flows, streamers and horseshoe in the HD142527 disc
• Dust depleted inner disks in a large sample of transition disks through long-baseline ALMA observations
• The Eccentric Cavity, Triple Rings, Two-Armed Spirals, and Double Clumps of the MWC 758 Disk
• An Inner Hole in the Disk around TW Hydrae Resolved in 7 Millimeter Dust Emission
• The Nature of Transition Circumstellar Disks I. The Ophiuchus Molecular Cloud
• A Spitzer c2d Legacy Survey to Identify and Characterize Disks with Inner Dust Holes
• The Disk Substructures at High Angular Resolution Project (DSHARP): IV. Characterizing substructures and interactions in disks around multiple star systems
• A Multiplicity Survey of the Rho Ophiuchi Molecular Clouds
• Evidence for a massive dust-trapping vortex connected to spirals: a multi-wavelength analysis of the HD~135344B protoplanetary disk
• Observational constraints on dust disk sizes in tidally truncated protoplanetary disks in multiple systems in the Taurus region
• Dust unveils the formation of a mini-Neptune planet in a protoplanetary ring
• Protoplanetary Disks in $\rho$ Ophiuchus as Seen From ALMA
• The Ophiuchus DIsk Survey Employing ALMA (ODISEA): Disk Dust Mass Distributions across Protostellar Evolutionary Classes
• A tidal encounter caught in the act: modelling a star-disc fly-by in the young RW Aurigae system
• Flybys in protoplanetary discs: II. Observational signatures
• Hints on the origins of particle traps in protoplanetary disks given by the $M_{\mathrm{dust}}-M_{\star }$ relation
• Long Baseline Observations of the HD100546 Protoplanetary Disk with ALMA
• Ongoing flyby in the young multiple system UX Tauri
• Resolving the FU Ori System with ALMA: Interacting Twin Disks?
• Signatures of an eccentric disc cavity: Dust and gas in IRS 48
• Alma Survey Of Circumstellar Disks In The Young Stellar Cluster IC 348
• A ring-like concentration of mm-sized particles in Sz 91
• The Ophiuchus DIsc Survey Employing ALMA (ODISEA). II. The effect of stellar multiplicity on disc properties
• Evidence of a past disc-disc encounter: HV and DO Tau
• Spirals inside the millimeter cavity of transition disk SR 21
• Accretion in rho-Ophiuchi brown dwarfs: infrared hydrogen line ratios
• Observational diagnostics of elongated planet-induced vortices with realistic planet formation timescales
• The TRENDS High-contrast Imaging Survey. VIII. Compendium of Benchmark Objects

Cited by in corpus (7)

• The Ophiuchus DIsc Survey Employing ALMA (ODISEA)-III: the evolution of substructures in massive discs at 3-5 au resolution
• Transition disks: the observational revolution from SEDs to imaging
• Substructures in Compact Disks of the Taurus Star-forming Region
• CAMPOS II. The onset of protostellar disk substructures and planet formation
• How to form compact & other longer-lived planet-induced vortices: VSI, planet migration, or re-triggers, but not feedback
• A Large Double-ring Disk around the Taurus M Dwarf J04124068+2438157
• Gas distribution in ODISEA sources from ALMA long-baseline observations in ${}^{12}$CO(2-1)