Reference : Dust in the inner regions of debris disks around A stars
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/19306
Dust in the inner regions of debris disks around A stars
English
Akeson, R. L. [Michelson Science Center, Caltech, Pasadena, CA 91125, USA]
Ciardi, D. R. [Michelson Science Center, Caltech, Pasadena, CA 91125, USA]
Millan-Gabet, R. [Michelson Science Center, Caltech, Pasadena, CA 91125, USA]
Merand, A. [Center for High Angular Resolution Astronomy, Georgia State University, Atlanta, GA 30302, USA ; Current address: European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago 19, Chile]
Di Folco, E. [ > > ]
Monnier, J. D. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA]
Beichman, C. A. [Michelson Science Center, Caltech, Pasadena, CA 91125, USA]
Absil, Olivier mailto [Université de Liège - ULg > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS) >]
Aufdenberg, J. [Physical Sciences Department, Embry-Riddle Aeronautical University, Daytona Beach, FL 32114, USA]
McAlister, H. [Center for High Angular Resolution Astronomy, Georgia State University, Atlanta, GA 30302, USA]
ten Brummelaar, T. [ > > ]
Sturmann, J. [Center for High Angular Resolution Astronomy, Georgia State University, Atlanta, GA 30302, USA]
Sturmann, L. [Center for High Angular Resolution Astronomy, Georgia State University, Atlanta, GA 30302, USA]
Turner, N. [Center for High Angular Resolution Astronomy, Georgia State University, Atlanta, GA 30302, USA]
1-Feb-2009
Astrophysical Journal
University of Chicago Press
691
1896-1908
Yes (verified by ORBi)
International
0004-637X
Chicago
IL
[en] circumstellar matter ; stars: individual: beta Leo, zeta Lep
[en] We present infrared interferometric observations of the inner regions of two A-star debris disks, beta Leo and zeta Lep, using the FLUOR instrument at the CHARA interferometer on both short (30 m) and long (> 200 m) baselines. For the target stars, the short-baseline visibilities are lower than expected for the stellar photosphere alone, while those of a check star, delta Leo, are not. We interpret this visibility offset of a few percent as a near-infrared (NIR) excess arising from dust grains which, due to the instrumental field of view, must be located within several AU of the central star. For beta Leo, the NIR excess-producing grains are spatially distinct from the dust which produces the previously known mid-infrared (MIR) excess. For zeta Lep, the NIR excess may be spatially associated with the MIR excess-producing material. We present simple geometric models which are consistent with the NIR and MIR excesses and show that for both objects, the NIR-producing material is most consistent with a thin ring of dust near the sublimation radius, with typical grain sizes smaller than the nominal radiation pressure blowout radius. Finally, we discuss possible origins of the NIR-emitting dust in the context of debris disk evolution models.
Researchers
http://hdl.handle.net/2268/19306
10.1088/0004-637X/691/2/1896
http://adsabs.harvard.edu/abs/2009ApJ...691.1896A
http://www.iop.org/EJ/abstract/0004-637X/645/1/664/ - Copyright The American Astronomical Society (AAS) and IOP Publishing Limited 2009
http://de.arxiv.org/abs/0810.3701

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