An icy Kuiper belt around the young solar-type star HD 181327

Lebreton, J.; Augereau, J.-C.; Thi, W. F.; Roberge, Aki; Donaldson, Jessica; Schneider, Glenn; Maddison, Sarah; Ménard, F.; Riviére-Marichalar, P.; Mathews, Geoffrey S.; Kamp, I.; Pinte, C.; Dent, W. R. F.; Barrado, D.; Duchêne, Gaspard; Gonzalez, Jean-François; Grady, C. A.; Meeus, G.; Pantin, E.; Williams, Jonathan P.; Woitke, P.

doi:10.1051/0004-6361/201117714

Cited by 105 publications

(170 citation statements)

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“…A similar model that incorporates porous core-mantle silicate grains, additionally covered by ice in the outer region of the disc, also reproduces the β Pic observations (Pantin et al 1997;Li & Greenberg 1998;Augereau et al 2001). Lebreton et al (2012) tested various chemical compositions for the debris around HD 181327. They find that the SED is mostly consistent with grains consisting of amorphous silicate and carbonaceous material with a dominant fraction of ice.…”

Section: Materials Compositionsupporting

confidence: 54%

Collisional modelling of the AU Microscopii debris disc

Schüppler

Löhne

Krivov

et al. 2015

A&A

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AU Microscopii's debris disc is one of the most famous and best-studied debris discs and one of only two resolved debris discs around M stars. We perform in-depth collisional modelling of the AU Mic disc including stellar radiative and corpuscular forces (stellar winds), aiming at a comprehensive understanding of the dust production and the dust and planetesimal dynamics in the system. Our models are compared to a suite of observational data for thermal and scattered light emission, ranging from the ALMA radial surface brightness profile at 1.3 mm to spatially resolved polarisation measurements in the visible. Most of the data are shown to be reproduced with dust production in a belt of planetesimals with an outer edge at around 40 au and subsequent inward transport of dust by stellar winds. A low dynamical excitation of the planetesimals with eccentricities up to 0.03 is preferred. The radial width of the planetesimal belt cannot be constrained tightly. Belts that are 5 au and 17 au wide, as well as a broad 44 au-wide belt, are consistent with observations. All models show surface density profiles that increase with distance from the star up to ≈40 au, as inferred from observations. The best model is achieved by assuming a stellar mass loss rate that exceeds the solar one by a factor of 50. The models reproduce the spectral energy distribution and the shape of the ALMA radial profile well, but deviate from the scattered light observations more strongly. The observations show a bluer disc colour and a lower degree of polarisation for projected distances <40 au than predicted by the models. These deviations may be reduced by taking irregularly shaped dust grains which have scattering properties different from the Mie spheres used in this work. From tests with a handful of selected dust materials, we favour mixtures of silicate, carbon, and ice of moderate porosity. We also address the origin of the unresolved central excess emission detected by ALMA and show that it cannot stem from an additional inner belt alone. Instead, it should derive, at least partly, from the chromosphere of the central star.

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Section: Materials Compositionsupporting

confidence: 54%

Collisional modelling of the AU Microscopii debris disc

Schüppler

Löhne

Krivov

et al. 2015

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“…Hence, we assumed a simple geometrical model of a ring-like dust disk. We used the GRaTer code (Augereau et al 1999;Lebreton et al 2012) to calculate synthetic scattered-light images of optically thin disks, assuming axial symmetry about their rotation axis, and inject these models into the real data. In this study, we assumed a dust number density of (in cylindrical coordinates):…”

Section: Reliability Of the Spine Deviation From Midplanementioning

confidence: 99%

Morphology of the very inclined debris disk around HD 32297

Boccaletti

Augereau

Lagrange

et al. 2012

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Context. Direct imaging of circumstellar disks at high angular resolution is mandatory to provide morphological information that constrains their properties, in particular the spatial distribution of dust. For a long time, this challenging objective was, in most cases, only within the realm of space telescopes from the visible to the infrared. New techniques combining observing strategy and data processing now allow very high-contrast imaging with 8-m class ground-based telescopes (10 −4 to 10 −5 at ∼1 ) and complement space telescopes while improving angular resolution at near infrared wavelengths. Aims. We present the results of a program carried out at the VLT with NACO to image known debris disks with higher angular resolution in the near-infrared than ever before in order to study morphological properties and ultimately detect the signpost of planets. Methods. The observing method makes use of advanced techniques of adaptive optics, coronagraphy, and differential imaging, a combination designed to directly image exoplanets with the upcoming generation of "planet finders" such as GPI (Gemini Planet Imager) and SPHERE (Spectro-Polarimetric High contrast Exoplanet REsearch). Applied to extended objects such as circumstellar disks, the method is still successful but produces significant biases in terms of photometry and morphology. We developed a new model-matching procedure to correct for these biases and hence provide constraints on the morphology of debris disks. Results. From our program, we present new images of the disk around the star HD 32297 obtained in the H (1.6 μm) and Ks (2.2 μm) bands with an unprecedented angular resolution (∼65 mas). The images show an inclined thin disk detected at separations larger than 0.5−0.6 . The modeling stage confirms a very high inclination (i = 88 • ) and the presence of an inner cavity inside r 0 ≈ 110 AU. We also find that the spine (line of maximum intensity along the midplane) of the disk is curved, which we attribute to a large anisotropic scattering-factor (g ≈ 0.5, which is valid for an non-edge-on disk). Conclusions. Our modeling procedure is relevant to interpreting images of circumstellar disks observed with angular differential imaging. It allows us to both reduce the biases and estimate the disk parameters.

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“…An emission model including a grain size distribution instead of a fixed f T as in our current model would be more realistic, but this can be best implemented only if the SED is finely sampled spectroscopically from mid-IR to submm (e.g. Lebreton et al 2012).…”

Section: Combined Fit Of the Three Pacs Imagesmentioning

confidence: 99%

“…When the SED of a debris disk is finely sampled spectroscopically from mid-IR to submm, a parameter search for composition, structure, size distribution of the grains can be conducted usefully (e.g. Lebreton et al 2012). Such a parameter search would be degenerate for GJ 581 because of its limited photometry, and so these effects have been reduced to the single parameter f T in our model.…”

Section: Dust Temperature In the Cold Diskmentioning

confidence: 99%

A DEBRIS disk around the planet hosting M-star GJ 581 spatially resolved withHerschel

Lestrade

Matthews

Sibthorpe

et al. 2012

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Debris disks have been found primarily around intermediate and solar mass stars (spectral types A-K) but rarely around low mass M-type stars. We have spatially resolved a debris disk around the remarkable M3-type star GJ 581 hosting multiple planets using deep PACS images at 70, 100 and 160 μm as part of the DEBRIS Program on the Herschel Space Observatory. This is the second spatially resolved debris disk found around an M-type star, after the one surrounding the young star AU Mic (12 Myr). However, GJ 581 is much older (2-8 Gyr), and is X-ray quiet in the ROSAT data. We fit an axisymmetric model of the disk to the three PACS images and found that the best fit model is for a disk extending radially from 25 ± 12 AU to more than 60 AU. Such a cold disk is reminiscent of the Kuiper belt but it surrounds a low mass star (0.3 M ) and its fractional dust luminosity L dust /L * of ∼10 −4 is much higher. The inclination limits of the disk found in our analysis make the masses of the planets small enough to ensure the long-term stability of the system according to some dynamical simulations. The disk is collisionally dominated down to submicron-sized grains and the dust cannot be expelled from the system by radiation or wind pressures because of the low luminosity and low X-ray luminosity of GJ 581. We suggest that the correlation between low-mass planets and debris disks recently found for G-type stars also applies to M-type stars. Finally, the known planets, of low masses and orbiting within 0.3 AU from the star, cannot dynamically perturb the disk over the age of the star, suggesting that an additional planet exists at larger distance that is stirring the disk to replenish the dust.

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An icy Kuiper belt around the young solar-type star HD 181327

Cited by 105 publications

References 50 publications

Collisional modelling of the AU Microscopii debris disc

Collisional modelling of the AU Microscopii debris disc

Morphology of the very inclined debris disk around HD 32297

A DEBRIS disk around the planet hosting M-star GJ 581 spatially resolved withHerschel

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