The AU Mic Debris Disk: far-infrared and submillimeter resolved imaging

Abstract

We present far-infrared and submillimeter maps from the Herschel Space Observatory and the James Clerk Maxwell Telescope of the debris disk host star AU Microscopii. Disk emission is detected at 70, 160, 250, 350, 450, 500 and 850 micron. The disk is resolved at 70, 160 and 450 micron. In addition to the planetesimal belt, we detect thermal emission from AU Mic's halo for the first time. In contrast to the scattered light images, no asymmetries are evident in the disk. The fractional luminosity of the disk is $3.9\times 10^{-4}$ and its mm-grain dust mass is 0.01 MEarth (+/- 20%). We create a simple spatial model that reconciles the disk SED as a blackbody of 53 +/- 2 K (a composite of 39 and 50 K components) and the presence of small (non-blackbody) grains which populate the extended halo. The best fit model is consistent with the "birth ring" model explored in earlier works, i.e., an edge-on dust belt extending from 8.8-40 AU, but with an additional halo component with an $r^{-1.5}$ surface density profile extending to the limits of sensitivity (140 AU). We confirm that AU Mic does not exert enough radiation force to blow out grains. For stellar mass loss rates of 10-100x solar, compact (zero porosity) grains can only be removed if they are very small, consistently with previous work, if the porosity is 0.9, then grains approaching 0.1 micron can be removed via corpuscular forces (i.e., the stellar wind).

accepted to the Astrophysical Journal

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Cited by in corpus (34)

• Debris Disks: Structure, Composition, and Variability
• SONS: The JCMT legacy survey of debris discs in the submillimetre
• Investigating the young AU~Mic system with SPIRou: large-scale stellar magnetic field and close-in planet mass
• The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure
• ALMA observations of the multiplanet system 61 Vir: What lies outside super-Earth systems?
• Stellar Winds and Dust Avalanches in the AU Mic Debris Disk
• A WISE-based search for debris discs amongst M-dwarfs in nearby, young, moving groups
• Gemini Planet Imager Spectroscopy of the Dusty Substellar Companion HD 206893 B
• Observability of Debris Discs around M-stars
• The Planet Formation Potential Around a 45 Myr old Accreting M Dwarf
• Giant Impacts and Debris Disk Morphology
• High Fidelity Imaging of the Inner AU Mic Debris Disk: Evidence of Differential Wind Sculpting?
• Rave: A non-parametric method for recovering the surface brightness and height profiles of edge-on debris disks
• Multiwavelength Vertical Structure in the AU Mic Debris Disk: Characterizing the Collisional Cascade
• Stumbling over planetary building blocks: AU Microscopii as an example of the challenge of retrieving debris-disk dust properties
• Discovery of an Edge-on Circumstellar Debris Disk Around BD+45${}^{\circ }$598: a Newly Identifed Member of the $\beta$ Pictoris Moving Group
• Relating grain size distributions in circumstellar discs to the spectral index at millimetre wavelengths
• The big sibling of AU Mic: a cold dust-rich debris disk around CP-72 2713 in the $\beta$ Pic moving group
• Optical Coronagraphic Spectroscopy of AU Mic: Evidence of Time Variable Colors?
• Herschel Observations of Disks around Late-type Stars
• ALMA imaging of the M-dwarf Fomalhaut C's debris disc
• Four new PLanetesimals Around TYpical and Pre-main seqUence Stars (PLATYPUS) Debris Discs at 8.8mm
• Probing the innermost region of the AU~Microscopii debris disk
• Clumpy dust rings around non-accreting young stars
• Seeking echoes of circumstellar disks in Kepler light curves
• Multi-wavelength aperture polarimetry of debris disc host stars
• The Mysterious Affair of the H${}_2$ in AU Mic
• ALMA's view of the M-dwarf GSC 07396-00759's edge-on debris disc: AU Mic's coeval twin
• Detection and Characterization of Extrasolar Planets through Mean-Motion Resonances. II. The Effect of the Planet's Orbital Eccentricity on Debris Disk Structures
• The triple system AT Mic AB + AU Mic in the beta Pictoris Association
• AU Mic b is the Youngest Planet to have a Spin-Orbit Alignment Measurement
• Resonant structures in exozodiacal clouds created by exo-Earths in the habitable zone of late-type stars
• A Catalogue of Interstellar Material Delivery From Nearby Debris Disks
• Interferometric Detection and Orbit Modeling of the Subcomponent in the Hot-dust System $\kappa$ Tuc A: A Low-mass Star on an Eccentric Orbit in a Hierarchical-quintuple System