scholarly journals HD141569A: Disk Dissipation Caught in Action

2015 ◽  
Vol 10 (S314) ◽  
pp. 201-202 ◽  
Author(s):  
J. Péricaud ◽  
E. Di Folco ◽  
A. Dutrey ◽  
J.-C. Augereau ◽  
V. Piétu ◽  
...  
Keyword(s):  
Scattered Light ◽  
Dust Emission ◽  
Debris Disks ◽  
Debris Disk ◽  
Multiple Rings

AbstractDebris disks are usually thought to be gas-poor, the gas being dissipated by accretion or evaporation during the protoplanetary phase. HD141569A is a 5 Myr old star harboring a famous debris disk, with multiple rings and spiral features. I present here the first PdBI maps of the 12CO(2−1), 13CO(2−1) gas and dust emission at 1.3 mm in this disk. The analysis reveals there is still a large amount of (primordial) gas extending out to 250 AU, i.e. inside the rings observed in scattered light. HD141569A is thus a hybrid disk with a huge debris component, where dust has evolved and is produced by collisions, with a large remnant reservoir of gas.

scholarly journals Constraining the detectability of water ice in debris disks

2019 ◽  
Vol 629 ◽  
pp. A141
Author(s):  
M. Kim ◽  
S. Wolf ◽  
A. Potapov ◽  
H. Mutschke ◽  
C. Jäger
Keyword(s):  
Scattered Light ◽  
Spectral Energy ◽  
Debris Disks ◽  
Water Ice ◽  
Spatially Resolved ◽  
Infrared Telescope ◽  
Effective Medium Theories ◽  
Debris Disk ◽  
Highly Porous ◽  
Entire Planet

Context. Water ice is important for the evolution and preservation of life. Identifying the distribution of water ice in debris disks is therefore of great interest in the field of astrobiology. Furthermore, icy dust grains are expected to play important roles throughout the entire planet formation process. However, currently available observations only allow deriving weak conclusions about the existence of water ice in debris disks. Aims. We investigate whether it is feasible to detect water ice in typical debris disk systems. We take the following ice destruction mechanisms into account: sublimation of ice, dust production through planetesimal collisions, and photosputtering by UV-bright central stars. We consider icy dust mixture particles with various shapes consisting of amorphous ice, crystalline ice, astrosilicate, and vacuum inclusions (i.e., porous ice grains). Methods. We calculated optical properties of inhomogeneous icy dust mixtures using effective medium theories, that is, Maxwell-Garnett rules. Subsequently, we generated synthetic debris disk observables, such as spectral energy distributions and spatially resolved thermal reemission and scattered light intensity and polarization maps with our code DMS. Results. We find that the prominent ~3 and 44 μm water ice features can be potentially detected in future observations of debris disks with the James Webb Space Telescope (JWST) and the Space Infrared telescope for Cosmology and Astrophysics (SPICA). We show that the sublimation of ice, collisions between planetesimals, and photosputtering caused by UV sources clearly affect the observational appearance of debris disk systems. In addition, highly porous ice (or ice-rich aggregates) tends to produce highly polarized radiation at around 3 μm. Finally, the location of the ice survival line is determined by various dust properties such as a fractional ratio of ice versus dust, physical states of ice (amorphous or crystalline), and the porosity of icy grains.

scholarly journals A Resolved Millimeter Emission Belt in the AU Mic Debris Disk

2013 ◽  
Vol 8 (S299) ◽  
pp. 313-317
Author(s):  
Meredith MacGregor
Keyword(s):  
Angular Resolution ◽  
Scattered Light ◽  
Dust Emission ◽  
Emission Peak ◽  
Parametric Models ◽  
Central Component ◽  
Millimeter Wavelengths ◽  
Stellar Photosphere ◽  
Debris Disk ◽  
Centroid Position

AbstractImaging debris disks at millimeter wavelengths is important, because emission at these long wavelengths is dominated by large grains with dynamics similar to the population of dust-producing planetesimals. We have used the SMA and ALMA to make 1.3 millimeter observations of the debris disk surrounding the nearby (9.9 pc), ~10 Myr-old, M-type flare star AU Microscopii. We characterize the disk by implementing Markov Chain Monte Carlo methods to fit parametric models to the visibilities. The millimeter observations reveal a belt of dust emission that peaks at a radius of 40 AU. This outer size scale agrees with predictions for a reservoir of planetesimals (a “birth ring”) based on the shape of the midplane scattered light profile. We do not find any significant asymmetries in the structure or the centroid position of the emission belt. The ALMA observations with a resolution of 0.6 arcsec (6 AU) also reveal a previously unknown central emission peak, ~6 times brighter than the stellar photosphere at these wavelengths. This central component remains unresolved and could be explained by stellar activity or an inner planetesimal belt located ≲3 AU from the star and containing roughly 1% the mass of the outer belt. Future observations with higher angular resolution will be able to distinguish between these possibilities.

scholarly journals Multiple Rings of Millimeter Dust Emission in the HD 15115 Debris Disk

2019 ◽  
Vol 877 (2) ◽  
pp. L32 ◽  
Author(s):  
Meredith A. MacGregor ◽  
Alycia J. Weinberger ◽  
Erika R. Nesvold ◽  
A. Meredith Hughes ◽  
D. J. Wilner ◽  
...  
Keyword(s):  
Dust Emission ◽  
Debris Disk ◽  
Multiple Rings

scholarly journals Warm Debris Disks with WISE and HST

2015 ◽  
Vol 10 (S314) ◽  
pp. 175-178 ◽  
Author(s):  
Deborah Padgett ◽  
Karl Stapelfeldt
Keyword(s):  
Scattered Light ◽  
Terrestrial Planets ◽  
Wide Field ◽  
Debris Disks ◽  
Circumstellar Material ◽  
Excess Emission ◽  
Sky Survey ◽  
Debris Disk ◽  
Infrared Survey

AbstractUsing 22 μm data from the Wide Field Infrared Survey Explorer (WISE), we have completed a sensitive all-sky survey for debris disks in Hipparcos and Tycho catalog stars within 120 pc. This warm excess emission traces material in the circumstellar region likely to host terrestrial planets. Several hundred previously unknown debris disk candidates were identified. We are currently performing follow-up observations to characterize the stars, companions, and circumstellar material in these systems with a variety of facilities including Keck, Herschel, and HST. Thirteen WISE debris disks have been observed to date using HST/STIS coronagraphy. Five of these disks have been detected in scattered light. One is a large and highly asymmetric edge-on disk which appears to be both warped and bifurcated.

scholarly journals HD 117214 debris disk: scattered-light images and constraints on the presence of planets

2020 ◽  
Vol 635 ◽  
pp. A19 ◽  
Author(s):  
N. Engler ◽  
C. Lazzoni ◽  
R. Gratton ◽  
J. Milli ◽  
H. M. Schmid ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Scattered Light ◽  
High Sensitivity ◽  
3D Models ◽  
Ring Structure ◽  
Geometrical Parameters ◽  
Debris Disks ◽  
Disk Structure ◽  
Ring Structures ◽  
Debris Disk

Context. Young stars with debris disks are the most promising targets for an exoplanet search because debris indicate a successful formation of planetary bodies. Debris disks can be shaped by planets into ring structures that give valuable indications on the presence and location of planets in the disk. Aims. We performed observations of the Sco-Cen F star HD 117214 to search for planetary companions and to characterize the debris disk structure. Methods. HD 117214 was observed with the SPHERE subsystems IRDIS, IFS, and ZIMPOL at optical and near-IR wavelengths using angular and polarimetric differential imaging techniques. This provided the first images of scattered light from the debris disk with the highest spatial resolution of 25 mas and an inner working angle <0.1″. With the observations with IRDIS and IFS we derived detection limits for substellar companions. The geometrical parameters of the detected disk were constrained by fitting 3D models for the scattering of an optically thin dust disk. Investigating the possible origin of the disk gap, we introduced putative planets therein and modeled the planet–disk and planet–planet dynamical interactions. The obtained planetary architectures were compared with the detection limit curves. Results. The debris disk has an axisymmetric ring structure with a radius of 0.42(±0.01)″ or ~45 au and an inclination of 71(±2.5)° and exhibits a 0.4″ (~40 au) wide inner cavity. From the polarimetric data, we derive a polarized flux contrast for the disk of (Fpol)disk/F∗ = (3.1 ± 1.2) × 10−4 in the RI band. Conclusions. The fractional scattered polarized flux of the disk is eight times lower than the fractional IR flux excess. This ratio is similar to the one obtained for the debris disk HIP 79977, indicating that dust radiation properties are similar for these two disks. Inside the disk cavity we achieve high-sensitivity limits on planetary companions with a mass down to ~4 MJ at projected radial separations between 0.2″ and 0.4″. We can exclude stellar companions at a radial separation larger than 75 mas from the star.

scholarly journals The Debris Disk Explorer: a balloon-borne coronagraph for observing debris disks

2013 ◽  
Author(s):  
Lewis C. Roberts ◽  
Geoffrey Bryden ◽  
Wesley Traub ◽  
Stephen Unwin ◽  
John Trauger ◽  
...  
Keyword(s):  
Debris Disks ◽  
Debris Disk

scholarly journals Expelled grains from an unseen parent body around AU Microscopii

2017 ◽  
Vol 607 ◽  
pp. A65 ◽  
Author(s):  
É. Sezestre ◽  
J.-C. Augereau ◽  
A. Boccaletti ◽  
P. Thébault
Keyword(s):  
Point Source ◽  
Stellar Wind ◽  
Local Density ◽  
Dust Emission ◽  
Parent Body ◽  
Static Case ◽  
Dust Grains ◽  
Periodic Process ◽  
The Common ◽  
Debris Disk

Context. Recent observations of the edge-on debris disk of AU Mic have revealed asymmetric, fast outward-moving arch-like structures above the disk midplane. Although asymmetries are frequent in debris disks, no model can readily explain the characteristics of these features. Aims. We present a model aiming to reproduce the dynamics of these structures, more specifically their high projected speeds and their apparent position. We test the hypothesis of dust emitted by a point source and then expelled from the system by the strong stellar wind of this young M-type star. In this model we make the assumption that the dust grains follow the same dynamics as the structures, i.e., they are not local density enhancements. Methods. We perform numerical simulations of test particle trajectories to explore the available parameter space, in particular the radial location R0 of the dust producing parent body and the size of the dust grains as parameterized by the value of β (ratio of stellar wind and radiation pressure forces over gravitation). We consider the cases of a static and of an orbiting parent body. Results. We find that for all considered scenarios (static or moving parent body), there is always a set of (R0,β) parameters able to fit the observed features. The common characteristics of these solutions is that they all require a high value of β, of around 6. This means that the star is probably very active, and the grains composing the structures are submicronic in order for observable grains to reach such high β values. We find that the location of the hypothetical parent body is closer in than the planetesimal belt, around 8 ± 2 au (orbiting case) or 28 ± 7 au (static case). A nearly periodic process of dust emission appears, of 2 yr in the orbiting scenarios and 7 yr in the static case. Conclusions. We show that the scenario of sequential dust releases by an unseen point-source parent body is able to explain the radial behavior of the observed structures. We predict the evolution of the structures to help future observations discriminate between the different parent body configurations that have been considered. In the orbiting parent body scenario, we expect new structures to appear on the northwest side of the disk in the coming years.

scholarly journals Debris Disk Science with the Palomar ExAO System: First Results

2013 ◽  
Vol 8 (S299) ◽  
pp. 72-73 ◽  
Author(s):  
Matthew Wahl ◽  
Stanimir Metchev ◽  
Rahul Patel ◽  
Eugene Serabyn ◽  
Dimitri Mawet ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Scattered Light ◽  
Outer Ring ◽  
Imaging Results ◽  
First Results ◽  
Debris Disk ◽  
First Time ◽  
Adaptive Optics System

AbstractWe present first imaging results from the PALM-3000 adaptive optics system and PHARO camera on the Hale 5 m telescope. Observations using a vector vortex coronagraph have given us direct detections of the two-ring dusty debris system around the star HD 141569. Our observations reveal the inner clearing in the disk to unprecedentedly small angular separations, and are the most sensitive yet at the H and K bands. We are for the first time able to measure and compare the colors of the scattered light in the inner and outer dust rings, and find that the outer ring is significantly bluer than the inner ring.

scholarly journals On the solar system—debris disk connection

2007 ◽  
Vol 3 (S249) ◽  
pp. 347-354 ◽  
Author(s):  
Amaya Moro-Martín
Keyword(s):  
Solar System ◽  
Debris Disks ◽  
Debris Disk

AbstractThis paper emphasizes the connection between solar and extra-solar debris disks: how models and observations of the Solar System are helping us understand the debris disk phenomenon, and vice versa, how debris disks are helping us place our Solar System into context.

scholarly journals Observational signatures of eccentric Jupiters inside gas cavities in protoplanetary discs

2021 ◽  
Author(s):  
Clément Baruteau ◽  
Gaylor Wafflard-Fernandez ◽  
Romane Le Gal ◽  
Florian Debras ◽  
Andrés Carmona ◽  
...  
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
Scattered Light ◽  
Dust Emission ◽  
Three Dimensional ◽  
Continuum Emission ◽  
Integrated Intensity ◽  
Gas Cavity ◽  
Hydrodynamical Simulations ◽  
Small Dust

Abstract Predicting how a young planet shapes the gas and dust emission of its parent disc is key to constraining the presence of unseen planets in protoplanetary disc observations. We investigate the case of a 2 Jupiter mass planet that becomes eccentric after migrating into a low-density gas cavity in its parent disc. Two-dimensional hydrodynamical simulations are performed and post-processed by three-dimensional radiative transfer calculations. In our disc model, the planet eccentricity reaches ∼0.25, which induces strong asymmetries in the gas density inside the cavity. These asymmetries are enhanced by photodissociation and form large-scale asymmetries in 12CO J=3→2 integrated intensity maps. They are shown to be detectable for an angular resolution and a noise level similar to those achieved in ALMA observations. Furthermore, the planet eccentricity renders the gas inside the cavity eccentric, which manifests as a narrowing, stretching and twisting of iso-velocity contours in velocity maps of 12CO J=3→2. The planet eccentricity does not, however, give rise to detectable signatures in 13CO and C18O J=3→2 inside the cavity because of low column densities. Outside the cavity, the gas maintains near-circular orbits, and the vertically extended optically thick CO emission displays a four-lobed pattern in integrated intensity maps for disc inclinations $\gtrsim$ 30○. The lack of large and small dust inside the cavity in our model further implies that synthetic images of the continuum emission in the sub-millimetre, and of polarized scattered light in the near-infrared, do not show significant differences when the planet is eccentric or still circular inside the cavity.

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