The Vega Debris Disk -- A Surprise from Spitzer

Abstract

We present high spatial resolution mid- and far-infrared images of the Vega debris disk obtained with the Multiband Imaging Photometer for Spitzer (MIPS). The disk is well resolved and its angular size is much larger than found previously. The radius of the disk is at least 43" (330 AU), 70"(543 AU), and 105" (815 AU) in extent at 24, 70 and 160 um, respectively. The disk images are circular, smooth and without clumpiness at all three wavelengths. The radial surface brightness profiles imply an inner boundary at a radius of 11"+/-2" (86 AU). Assuming an amalgam of amorphous silicate and carbonaceous grains, the disk can be modeled as an axially symmetric and geometrically thin disk, viewed face-on, with the surface particle number density following an r^-1 power law. The disk radiometric properties are consistent with a range of models using grains of sizes ~1 to ~50 um. We find that a ring, containing grains larger than 180 um and at radii of 86-200 AU from the star, can reproduce the observed 850 um flux, while its emission does not violate the observed MIPS profiles. This ring could be associated with a population of larger asteroidal bodies analogous to our own Kuiper Belt. Cascades of collisions starting with encounters amongthese large bodies in the ring produce the small debris that is blown outward by radiation pressure to much larger distances where we detect its thermal emission. The dust production rate is >~10^15 g/s based on the MIPS results. This rate would require a very massive asteroidal reservoir for the dust to be produced in a steady state throughout Vega's life. Instead, we suggest that the disk we imaged is ephemeral and that we are witnessing the aftermath of a large and relatively recent collisional event, and subsequent collisional cascade.

13 pages, 17 figures, accepted for publication in ApJ. (Figures 2, 3a, 3b and 4 have been degraded to lower resolutions.)

References in corpus (9)

• The Spitzer Space Telescope Mission
• Reduction Algorithms for the Multiband Imaging Photometer for Spitzer
• A dust ring around Epsilon Eridani: analogue to the young Solar System
• HST/ACS Coronagraphic Imaging of the Circumstellar Disk around HD1415659A
• Collisional Cascades in Planetesimal Disks II. Embedded Planets
• Structure in the Dusty Debris around Vega
• Infrared Views of the TW Hya Disk
• Millimeter-Wave Aperture Synthesis Imaging of Vega: Evidence for a Ring Arc at 95 AU
• Ages of late spectral type Vega-like stars

Cited by in corpus (124)

• The James Webb Space Telescope
• Debris Disk Evolution Around A Stars
• Imaging Extrasolar Giant Planets
• Debris disks in main sequence binary systems
• Transience of hot dust around sun-like stars
• Debris Disks: Structure, Composition, and Variability
• Spitzer IRS Spectroscopy of IRAS-Discovered Debris Disks
• The Debris Disk Around HR 8799
• Steady-state evolution of debris disks around A stars
• Variations on Debris Disks: Icy Planet Formation at 30-150 AU for 1-3 Solar Mass Main Sequence Stars
• 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
• Dust Dynamics, Surface Brightness Profiles, and Thermal Spectra of Debris Disks: The Case of AU Mic
• Techniques and Review of Absolute Flux Calibration from the Ultraviolet to the Mid-Infrared
• Accurate fundamental parameters for Lower Main Sequence Stars
• New Debris Disks Around Nearby Main Sequence Stars: Impact on The Direct Detection of Planets
• Debris Disks: Seeing Dust, Thinking of Planetesimals and Planets
• Asteroid Belts in Debris Disk Twins: VEGA and FOMALHAUT
• A 40 Myr Old Gaseous Circumstellar Disk at 49 Ceti: Massive CO-Rich Comet Clouds at Young A-Type Stars
• Vega is a rapidly rotating star
• Collisional processes and size distribution in spatially extended debris discs
• First Results from the CHARA Array VII: Long-Baseline Interferometric Measurements of Vega Consistent with a Pole-On, Rapidly Rotating Star
• Resolved Debris Discs Around A Stars in the Herschel DEBRIS Survey
• Epsilon Eridani's Planetary Debris Disk: Structure and Dynamics based on Spitzer and CSO Observations
• Formation and Evolution of Planetary Systems: Upper Limits to the Gas Mass in Disks Around Sun-like Stars
• Abundant Circumstellar Silica Dust and SiO Gas Created by a Giant Hypervelocity Collision in the ~12 Myr HD172555 System
• Circumstellar material in the Vega inner system revealed by CHARA/FLUOR
• Dust in Resonant Extrasolar Kuiper Belts - Grain Size and Wavelength Dependence of Disk Structure
• SONS: The JCMT legacy survey of debris discs in the submillimetre
• Disk Radii and Grain Sizes in Herschel-Resolved Debris Disks
• Outer edges of debris discs: how sharp is sharp?
• Structure and evolution of debris disks around F-type stars: I. Observations, database and basic evolutionary aspects
• Resolved Imaging of the HR 8799 Debris Disk with Herschel
• Explorations Beyond the Snow Line: Spitzer/IRS Spectra of Debris Disks Around Solar-Type Stars
• The Dust Properties of Eight Debris Disk Candidates as Determined by Submillimeter Photometry
• A Comprehensive Census of Nearby Infrared Excess Stars
• Hot exozodiacal dust resolved around Vega with IOTA/IONIC
• An 850 micron survey for dust around solar mass stars
• A Self-Consistent Model of the Circumstellar Debris Created by a Giant Hypervelocity Impact in the HD172555 System
• IRS Spectra of Solar-Type Stars: \break A Search for Asteroid Belt Analogs
• Variations on Debris Disks II. Icy Planet Formation as a Function of the Bulk Properties and Initial Sizes of Planetesimals
• The Correlation Between Metallicity and Debris Disk mass
• Herschel's "Cold Debris Disks": Background Galaxies or Quiescent Rims of Planetary Systems?
• Spitzer 24 micron Survey of Debris Disks in the Pleiades
• A possible architecture of the planetary system HR 8799
• Debris Distribution in HD 95086 - A Young Analog of HR 8799
• Mid-infrared resolution of a 3 AU-radius debris disk around Zeta Leporis
• A near-infrared interferometric survey of debris disc stars. II. CHARA/FLUOR observations of six early-type dwarfs
• The linear polarization of nearby bright stars measured at the parts per million level
• The low level of debris disk activity at the time of the Late Heavy Bombardment: a Spitzer study of Praesepe
• Formation and Evolution of Planetary Systems: Cold Outer Disks Associated with Sun-like stars
• The Vega Debris Disc: A view from Herschel
• The Debris Disk of Vega: A Steady-State Collisional Cascade, Naturally
• Planet Signatures in Collisionally Active Debris Discs: scattered light images
• Millimeter Imaging of the beta Pictoris Debris Disk: Evidence for a Planetesimal Belt
• SPITZER/IRAC-MIPS Survey of NGC2451A and B: Debris Disks at 50-80 million years
• Vega's hot dust from icy planetesimals scattered inward by an outward-migrating planetary system
• Formation of Narrow Dust Rings in Circumstellar Debris Disks
• A Resolved Millimeter Emission Belt in the AU Mic Debris Disk
• Spatially Resolved Images of Dust Belt(s) Around the Planet-hosting Subgiant Kappa CrB
• Inner mean-motion resonances with eccentric planets: A possible origin for exozodiacal dust clouds
• Herschel discovery of a new class of cold, faint debris discs
• An Unbiased Survey of 500 Nearby Stars for Debris Disks: A JCMT Legacy Program
• Modeling Collisional Cascades In Debris Disks: The Numerical Method
• Planetesimals in Debris Disks of Sun-like Stars
• Extreme Debris Disk Variability -- Exploring the Diverse Outcomes of Large Asteroid Impacts During the Era of Terrestrial Planet Formation
• The HIP 79977 debris disk in polarized light
• Could the Ultra Metal-poor Stars be Chemically Peculiar and Not Related to the First Stars?
• First Fruits of the Spitzer Space Telescope: Galactic and Solar System Studies
• Multi-Wavelength Modelling of the Beta Leo Debris Disc: 1, 2 or 3 planetesimal populations?
• EF Cha: Warm Dust Orbiting a Nearby 10 Myr Old Star
• Resolved Imaging of the HD191089 Debris Disc
• 12 and 18 micron images of dust surrounding HD 32297
• A Spitzer/IRAC Search for Substellar Companions of the Debris Disk Star epsilon Eridani
• The Exceptionally Large Debris Disk around γOphiuchi
• Thermal Infrared Constraint to a Planetary Companion of Vega with the MMT Adaptive Optics System
• Warm Dust around Cool Stars: Field M Dwarfs with WISE 12 or 22 Micron Excess Emission
• Spitzer/MIPS Limits on Asteroidal Dust in the Pulsar Planetary System PSR B1257+1
• Images of Vega Dust Ring at 350 and 450 microns: New Clues to the Trapping of Multiple-Sized Dust Particles in Planetary Resonances
• Spitzer Far-Infrared Detections of Cold Circumstellar Disks
• Multi-Epoch Observations of HD69830: High Resolution Spectroscopy and Limits to Variability
• Confirming the Primarily Smooth Structure of the Vega Debris Disk at Millimeter Wavelengths
• Dust Populations in the Iconic Vega Planetary System Resolved by ALMA
• Circumstellar disks and planets. Science cases for next-generation optical/infrared long-baseline interferometers
• Spitzer/MIPS 24 micron Detection of Photoevaporating Protoplanetary Disks
• 51 Ophiuchus: A Possible Beta Pictoris Analog Measured with the Keck Interferometer Nuller
• Survey of Nearby FGK Stars at 160 microns with Spitzer
• Resolving Structure in the Debris Disk around HD 206893 with ALMA
• What Sets the Radial Locations of Warm Debris Disks?
• Probing the Terrestrial Regions of Planetary Systems: Warm Debris Disks with Emission Features
• The Inner Debris Structure in the Fomalhaut Planetary System
• Water delivery to the TRAPPIST-1 planets
• Warm dusty discs: Exploring the A star 24um debris population
• The Frequency of Mid-Infrared Excess Sources in Galactic Surveys
• Using warm dust to constrain unseen planets
• Photoevaporation of Protoplanetary Disks
• The Structure of the β Leonis Debris Disk
• The debris disk around gamma Doradus resolved with Herschel
• Near Infrared High Resolution Spectroscopy and Spectro-astrometry of Gas in Disks around Herbig Ae/Be Stars
• Dusty Planetary Systems
• Emerging trends in metallicity and lithium properties of debris disc stars
• High-sensitivity search for clumps in the Vega Kuiper-belt. New PdBI 1.3mm observations
• A decade of radial-velocity monitoring of Vega and new limits on the presence of planets
• The Kuiper Belt and Other Debris Disks
• Dusty OB stars in the Small Magellanic Cloud - II: Extragalactic Disks or Examples of the Pleiades Phenomenon?
• A Possible Correlation between the Gaseous Drag Strength and Resonant Planetesimals in Planetary Systems
• Spectrophotometry of Very Bright Stars in the Southern Sky
• A decade-long magnetic monitoring of Vega
• Polarization of stars with debris disks: comparing observations with models
• Dusty Cometary Globules in W5
• A deep search for planets in the inner 15 au around Vega
• A Study of Ro-vibrational OH Emission from Herbig Ae/Be Stars
• Astrophysics in 2005
• Absorption of crystalline water ice in the far infrared at different temperatures
• On Grain Dynamics in Debris Discs: Continuous Outward Flows and Embedded Planets
• 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
• Signpost of Multiple Planets in Debris Disks
• Clumps and Axisymmetric Features in Debris Discs
• Deep Search for a scattered light dust halo around Vega with the Hubble Space Telescope
• Thermal and Optical Characterization of Near-Earth Objects: Science Commissioning of the Recently Upgraded Mid-Infrared Camera MIRSI on the NASA Infrared Telescope Facility
• Studies of Expolanets and Solar Systems with SPICA
• SKYSURF-11: A New Zodiacal Light Model Optimized for Optical Wavelengths
• The James Webb Space Telescope Absolute Flux Calibration. I. Program Design and Calibrator Stars
• Coronal and chromospheric emission in A-type stars