Circumbinary and circumstellar discs around the eccentric binary IRAS 04158+2805 — a testbed for binary–disc interaction
Year: 2021
Type: article
Abstract: ABSTRACT IRAS 04158+2805 has long been thought to be a very low mass T-Tauri star (VLMS) surrounded by a nearly edge-on, extremely large disc. Recent observations revealed that this source hosts a binary surrounded by an extended circumbinary disc with a central dust cavity. In this paper, we combine ALMA multiwavelength observations of continuum and 12CO line emission, with H α imaging and Keck astrometric measures of the binary to develop a coherent dynamical model of this system. The system features an azimuthal asymmetry detected at the western edge of the cavity in Band 7 observations and a wiggling outflow. Dust emission in ALMA Band 4 from the proximity of the individual stars suggests the presence of marginally resolved circumstellar discs. We estimate the binary orbital parameters from the measured arc of the orbit from Keck and ALMA astrometry. We further constrain these estimates using considerations from binary–disc interaction theory. We finally perform three SPH gas+dust simulations based on the theoretical constraints; we post-process the hydrodynamic output using radiative transfer Monte Carlo methods and directly compare the models with observations. Our results suggest that a highly eccentric e ∼ 0.5–0.7 equal mass binary, with a semimajor axis of ∼55 au, and small/moderate orbital plane versus circumbinary disc inclination θ ≲ 30° provides a good match with observations. A dust mass of ${\sim}1.5\times 10^{-4} \, {\rm M_\odot }$ best reproduces the flux in Band 7 continuum observations. Synthetic CO line emission maps qualitatively capture both the emission from the central region and the non-Keplerian nature of the gas motion in the binary proximity.
Institutions: University of Leicester, University of Milan, Centre National de la Recherche Scientifique, Institut de Planétologie et d'Astrophysique de Grenoble, Université Grenoble Alpes, University of California, Berkeley, California Institute of Technology, Jet Propulsion Laboratory, Monash University, University of Arizona
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Aeronautics and Space Administration, Universities Space Research Association, University of Leicester, European Commission, Nuclear Safety and Security Commission, Jet Propulsion Laboratory, Science and Technology Facilities Council, Australian Research Council, H2020 European Research Council
Awards: G136906088, G1541806023, G165597396, G1736745720, G1771230537, G2073976794, G2724489712, Gaps, rings and holes in protoplanetary discs, The DiRAC 2.5x Facility, G3403823835, G3531124447, G434337789, UNDERSTANDING THE REMARKABLE DIVERSITY OF PLANETARY SYSTEMS REVEALED IN PARTICULAR BY THE KEPLER MISSION IS A CENTRAL GOAL OF MODERN ASTROPHYSICS. TO SHED A NEW LIGHT ON THIS FUNDAMENTAL QUESTION THE CORE OBJECTIVE OF THIS PROJECT IS TO ASSESS THE TRUE DIVERSITY OF STRUCTURAL PROPERTIES AMONG PROTOPLANETARY DISKS. SPECIFICALLY WE AIM AT EVALUATING THE DEGREE TO WHICH PROCESSES SUCH AS VERTICAL SETTLING RADIAL MIGRATION AND DUST-GAS DECOUPLING ALL BELIEVED TO BE KEY INITIAL STEPS TOWARDS PLANET FORMATION ARE COMMON IN CIRCUMSTELLAR DISKS AND TO DETERMINE THE ROLE THEY PLAY IN DISK EVOLUTION. TO CIRCUMVENT THE HIGHLY AMBIGUOUS NATURE OF SPATIALLY UNRESOLVED OBSERVATIONS A DISK S STRUCTURE MUST BE PROBED THROUGH HIGH-RESOLUTION IMAGING OVER A BROAD RANGE OF WAVELENGTHS FROM VISIBLE SCATTERED LIGHT IMAGES TO RADIO WAVELENGTH THERMAL EMISSION MAPPING. DISKS THAT ARE FORTUITOUSLY ORIENTED SO THAT WE VIEW THEM NEARLY EDGE-ON PROVIDE A NATURAL OCCULTER TO THE GLARE OF THE CENTRAL STAR ENABLING STUDIES THAT ARE DAUNTING IF NOT OUTRIGHT IMPOSSIBLE FOR DISKS SEEN AT LOWER INCLINATIONS. IN PARTICULAR THE DISK S VERTICAL STRUCTURE IS IN FULL DISPLAY IN THIS CASE AND THE PRESENCE OF TENUOUS AMOUNTS OF MATERIAL AT LARGE DISTANCES FROM THE CENTRAL STAR IS READILY REVEALED THANKS TO THE NATURAL EFFECT OF LINE-OF-SIGHT INTEGRATION. OUR PROJECT WHICH BUILDS ON THE LEGACY OF SEVERAL SPITZER AND HERSCHEL SURVEYS TO IDENTIFY CANDIDATE EDGE-ON DISKS IN THE FIRST PLACE COMBINES HIGH-RESOLUTION IMAGING WITH HST ADAPTIVE OPTICS AND SUB-MILLIMETER INTERFEROMETRIC OBSERVATIONS WITH STATE-OF-THE-ART RADIATIVE TRANSFER MODELING. WITH OVER THREE DOZEN EDGE-ON DISKS AROUND SOLAR-TYPE AND LOW-MASS STARS ALREADY IMAGED WITH HST AND/OR GROUND-BASED ADAPTIVE OPTICS AS WELL AS ONGOING ALMA PROGRAMS TO MAP A LARGE SUBSET IN BOTH SUB-MILLIMETER DUST CONTINUUM AND MOLECULAR EMISSION MAPS WE ARE IN AN IDEAL POSITION TO PERFORM HIGHLY UNIFORM MODELING STUDIES ENABLING BOTH OBJECT-TO-OBJECT COMPARISONS AND A FULL CHARACTERIZATION OF THE OVERALL DEMOGRAPHICS OF PROTOPLANETARY DISKS. THIS THOROUGH PANCHROMATIC MODELING WILL ALLOW US TO ASSESS THE INTRINSIC DIVERSITY OF DISK STRUCTURE ON A SOUND STATISTICAL BASIS AND TO DRAW COMPARISONS WITH THE STATISTICAL PROPERTIES OF PLANETARY SYSTEMS. IN ADDITION WE WILL MAKE PREDICTIONS FOR FUTURE HIGH-RESOLUTION MID-INFRARED JWST OBSERVATIONS THAT WILL BRIDGE THE GAP THAT EXISTS BETWEEN EXISTING CAPABILITIES BY PROBING DEEPER INTO THESE DISKS. UNDERSTANDING THE PLANET FORMATION PROCESS THROUGH STUDIES OF PROTOPLANETARY DISKS AND EXPLAINING THE DIVERSITY OF PLANETARY SYSTEMS THAT EMERGE FROM IT IS DIRECTLY RELEVANT TO NASA S EXOPLANET RESEARCH PROGRAM. FURTHERMORE THIS PROJECT BUILDS ON OBSERVATIONS WITH PREVIOUS AND ONGOING SPACE MISSION LED BY OR WITH STRONG CONTRIBUTION FROM NASA AND WILL HELP PREPARE THE PLANNING AND INTERPRETATION OF FUTURE OBSERVATIONS OF PROTOPLANETARY DISKS WITH JWST. FINALLY BY DIRECTLY INVOLVING TWO UC BERKELEY UNDERGRADUATE STUDENTS THIS PROJECT WILL PROVIDE EXCITING OPPORTUNITIES FOR STUDENTS TO GET ENGAGED IN RESEARCH IN A STEM FIELD., Formation and evolution of planetary systems, Dust and gas in planet forming discs, G5660267321, G5768834005, Adversarial Models in Sensor Networks, G6537386148, G6800588795, G6802598382, G6873874887, G6926846737, G7108246583, DiRAC2: 100 Tflop/s HPC cluster procurement, G7521014512, Building planetary systems: linking architectures with formation, G7573294876, G7937591081, G8709550015, G8710138095, G8962111125, DiRAC 2.5 Operations 2017-2020
OpenAlex ID: W3186497294