Spatially resolved imaging of the two-component η Crv debris disk with Herschel
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We present far-infrared and submillimeter images of the η Crv debris disk system obtained with Herschel and SCUBA-2, as well as Hubble Space Telescope visible and near-infrared coronagraphic images. In the 70 μm Herschel image, we clearly separate the thermal emission from the warm and cold belts in the system, find no evidence for a putative dust population located between them, and precisely determine the geometry of the outer belt. We also find marginal evidence for azimuthal asymmetries and a global offset of the outer debris ring relative to the central star. Finally, we place stringent upper limits on the scattered light surface brightness of the outer ring. Using radiative transfer modeling, we find that it is impossible to account for all observed properties of the system under the assumption that both rings contain dust populations with the same properties. While the outer belt is in reasonable agreement with the expectations of steady-state collisional cascade models, albeit with a minimum grain size that is four times larger than the blow-out size, the inner belt appears to contain copious amounts of small dust grains, possibly below the blow-out size. This suggests that the inner belt cannot result from a simple transport of grains from the outer belt and rather supports a more violent phenomenon as its origin. We also find that the emission from the inner belt has not declined over three decades, a much longer timescale than its dynamical timescale, which indicates that the belt is efficiently replenished.
Duchêne , G , Arriaga , P , Wyatt , M , Kennedy , G , Sibthorpe , B , Lisse , C , Holland , W , Wisniewski , J , Clampin , M , Kalas , P , Pinte , C , Wilner , D , Booth , M , Horner , J , Matthews , B & Greaves , J 2014 , ' Spatially resolved imaging of the two-component η Crv debris disk with Herschel ' Astrophysical Journal , vol 784 , no. 2 . DOI: 10.1088/0004-637X/784/2/148
© 2014. The American Astronomical Society. All rights reserved.
This work was supported in part by NASA through a contract (No. 1353184, PI: H. M. Butner) issued by the Jet Propulsion Laboratory, California Institute of Technology under contract with NASA. We acknowledge the Service Commun de Calcul Intensif de l'Observatoire de Grenoble (SCCI) for computations on the super-computer funded by ANR (contracts ANR-07-BLAN-0221, ANR-2010-JCJC-0504-01 and ANR-2010-JCJC-0501-01) and the European Commission's 7th Framework Program (contract PERG06-GA-2009-256513). M.W. and G.K. are grateful for support from the European Union through ERC grant number 279973. C.L. acknowledges support from grants NASA NNX11AB21G and NSF AAG-NNX09AU31G in working on this project. P.K. acknowledges support from NASA NNX11AD21G, NSF AST-0909188, and JPL/NASA award NMO711043. M.B. acknowledges support from an NSERC Discovery Accelerator Supplement.
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