ALMA observations of the $\eta$ Corvi debris disc: inward scattering of CO-rich exocomets by a chain of 3-30 M${}_{\oplus }$ planets?

Abstract

While most of the known debris discs present cold dust at tens of AU, a few young systems exhibit hot dust analogous to the Zodiacal dust. $\eta$ Corvi is particularly interesting as it is old and it has both, with its hot dust significantly exceeding the maximum luminosity of an in-situ collisional cascade. Previous work suggested that this system could be undergoing an event similar to the Late Heavy Bombardment (LHB) soon after or during a dynamical instability. Here we present ALMA observations of $\eta$ Corvi with a resolution of 1."2 (~22au) to study its outer belt. The continuum emission is consistent with an axisymmetric belt, with a mean radius of 152au and radial FWHM of 46au, which is too narrow compared to models of inward scattering of an LHB-like scenario. Instead, the hot dust could be explained as material passed inwards in a rather stable planetary configuration. We also report a 4sigma detection of CO at ~ 20au. CO could be released in situ from icy planetesimals being passed in when crossing the H${}_2$O or CO${}_2$ ice lines. Finally, we place constraints on hidden planets in the disc. If a planet is sculpting the disc's inner edge, this should be orbiting at 75-100au, with a mass of 3-30 M${}_{\oplus }$ and an eccentricity < 0.08. Such a planet would be able to clear its chaotic zone on a timescale shorter than the age of the system and scatter material inwards from the outer belt to the inner regions, thus feeding the hot dust.

22 pages, 16 figures. Accepted for publication in MNRAS

References in corpus (26)

• New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey
• Ring shaped dust accumulation in transition disks
• Debris Disk Evolution Around A Stars
• Transience of hot dust around sun-like stars
• Pulkovo Compilation of Radial Velocities for 35495 Hipparcos Stars in a Common System
• Spitzer IRS Spectroscopy of IRAS-Discovered Debris Disks
• Variations on Debris Disks: Icy Planet Formation at 30-150 AU for 1-3 Solar Mass Main Sequence Stars
• Molecular Gas Clumps from the Destruction of Icy Bodies in the $\beta$ Pictoris Debris Disk
• The Complete Census of 70-um-Bright Debris Disks within the FEPS (Formation and Evolution of Planetary Systems) Spitzer Legacy Survey of Sun-like Stars
• Formation and Evolution of Planetary Systems (FEPS): Properties of Debris Dust around Solar-type Stars
• Long-Term Collisional Evolution of Debris Disks
• Abundant Circumstellar Silica Dust and SiO Gas Created by a Giant Hypervelocity Collision in the ~12 Myr HD172555 System
• Debris from giant impacts between planetary embryos at large orbital radii
• Extrasolar planets and brown dwarfs around A-F type stars VI. High precision RV survey of early type dwarfs with HARPS
• Do Two Temperature Debris Disks Have Multiple Belts?
• The History of the Solar System's Debris Disc: Observable Properties of the Kuiper Belt
• Exocometary gas structure, origin and physical properties around $\beta$ Pictoris through ALMA CO multi-transition observations
• Dynamical evolution of an eccentric planet and a less massive debris disc
• CO mass upper limits in the Fomalhaut ring - the importance of NLTE excitation in debris discs and future prospects with ALMA
• Planetesimal driven migration as an explanation for observations of high levels of warm, exozodiacal dust
• First-light LBT nulling interferometric observations: warm exozodiacal dust resolved within a few AU of eta Corvi
• The unseen planets of double belt debris disk systems
• Warm exo-Zodi from cool exo-Kuiper belts: the significance of P-R drag and the inference of intervening planets
• Extrasolar planets and brown dwarfs around AF-type stars. IX. The HARPS southern sample
• Signatures of massive collisions in debris discs
• Exo-zodi modelling for the Large Binocular Telescope Interferometer

Cited by in corpus (56)

• Detection of exocometary CO within the 440 Myr-old Fomalhaut belt: a similar CO+CO${}_2$ ice abundance in exocomets and Solar System comets
• The HOSTS survey for exozodiacal dust: Observational results from the complete survey
• SONS: The JCMT legacy survey of debris discs in the submillimetre
• Molecular gas in debris disks around young A-type stars
• A Complete ALMA Map of the Fomalhaut Debris Disk
• Likely Transiting Exocomets Detected by Kepler
• The Northern Arc of $\epsilon$ Eridani's Debris Ring as Seen by ALMA
• Planet populations inferred from debris discs: insights from 178 debris systems in the ISPY, LEECH and LIStEN planet-hunting surveys
• Solar System Physics for Exoplanet Research
• A gap in HD 92945's broad planetesimal disc revealed by ALMA
• ALMA observations of the narrow HR 4796A debris ring
• Resolving the FU Ori System with ALMA: Interacting Twin Disks?
• Population synthesis of exocometary gas around A stars
• On the Ubiquity and Stellar Luminosity Dependence of Exocometary CO Gas: Detection around M Dwarf TWA 7
• Insights into the planetary dynamics of HD 206893 with ALMA
• ALMA Discovery of Dust Belts Around Proxima Centauri
• Exocomets: A spectroscopic survey
• Exocomets from a Solar System Perspective
• ISPY -- NACO Imaging Survey for Planets around Young stars: Survey description and results from the first 2.5 years of observations
• A $75\%$ Occurrence Rate of Debris Discs around F stars in the $\beta$ Pic Moving Group
• Survey of planetesimal belts with ALMA: gas detected around the Sun-like star HD 129590
• High resolution ALMA and HST images of q${}^1$ Eri: an asymmetric debris disc with an eccentric Jupiter
• The unexpected narrowness of eccentric debris rings: a sign of eccentricity during the protoplanetary disc phase
• Constraining planetesimal stirring: how sharp are debris disc edges?
• A new sample of warm extreme debris disks from the ALLWISE catalog
• Lack of other molecules in CO-rich debris discs: is it primordial or secondary gas?
• Dust Populations in the Iconic Vega Planetary System Resolved by ALMA
• Dust size and spatial distributions in debris discs: predictions for exozodiacal dust dragged in from an exo-Kuiper belt
• Primordial or Secondary? Testing models of debris disk gas with ALMA
• Carbon monoxide gas produced by a giant impact in the inner region of a young system
• The Near Infrared Imager and Slitless Spectrograph for the James Webb Space Telescope -- IV. Aperture Masking Interferometry
• ALMA Images the Eccentric HD 53143 Debris Disk
• Extrasolar Kuiper Belts
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) I: Motivation, sample, data reduction, and results overview
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) II. The radial structure of debris discs
• Modelling the Spatial Distribution and Origin of CO Gas in Debris Disks
• Inner edges of planetesimal belts: collisionally eroded or truncated?
• EMISSA -- Exploring Millimeter Indicators of Solar-Stellar Activity I. The Initial mm-cm Main Sequence Star Sample
• Relating grain size distributions in circumstellar discs to the spectral index at millimetre wavelengths
• A PR drag origin for the Fomalhaut disk's pervasive inner dust: constraints on collisional strengths, icy composition, and embedded planets
• A Deep Search for Five Molecules in the 49 Ceti Debris Disk
• Four new PLanetesimals Around TYpical and Pre-main seqUence Stars (PLATYPUS) Debris Discs at 8.8mm
• A Mixed Stirring Mechanism for Debris Discs with Giant and Dwarf Planetary Perturbations
• Characterization of debris disks observed with SPHERE
• Formation of Multiple Dynamical Classes in the Kuiper Belt via Disk Dissipation
• Stellar winds can affect gas dynamics in debris disks and create observable belt winds
• Multi-wavelength, spatially resolved modelling of HD 48682's debris disc
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) VII: Optically thick gas with broad CO gaussian local line profiles in the HD 121617 disc
• Isolating the extreme debris disc signature -- explorations of eccentric extreme debris discs formed by giant impacts
• Discovery of Volatile Gas in the Giant Impact Disk around the 150-Myr old HD 23514
• Diversity of Exoplanets
• The search for gas in debris discs: ALMA detection of CO gas in HD 36546
• Resolving the large exoKuiper belt of the HD 126062 debris disc and extended gas emission in its vicinity
• HD 44892: The youngest (or oldest?) gas-harbouring debris disc around an intermediate mass star
• A Multi-Wavelength Study of the Highly Asymmetrical Debris Disk Around HD 111520
• Role of non-thermal processes in the quiescent and active millimeter spectrum of a young M dwarf