J/ApJ/823/108ivo://CDS.VizieR/J/ApJ/823/108doi:10.26093/cds/vizier.18230108CDSBallering N.P.Su K.Y.L.Rieke G.H.Gaspar A.2017-07-04T07:09:24Z2016-09-22T12:49:42ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frastronomical-modelsWe investigate whether varying the dust composition (described by the optical constants) can solve a persistent problem in debris disk modeling --the inability to fit the thermal emission without overpredicting the scattered light. We model five images of the {beta} Pictoris disk: two in scattered light from the Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph at 0.58{mu}m and HST/Wide Field Camera 3 (WFC3) at 1.16{mu}m, and three in thermal emission from Spitzer/Multiband Imaging Photometer for Spitzer (MIPS) at 24{mu}m, Herschel/PACS at 70{mu}m, and Atacama Large Millimeter/submillimeter Array at 870{mu}m. The WFC3 and MIPS data are published here for the first time. We focus our modeling on the outer part of this disk, consisting of a parent body ring and a halo of small grains. First, we confirm that a model using astronomical silicates cannot simultaneously fit the thermal and scattered light data. Next, we use a simple generic function for the optical constants to show that varying the dust composition can improve the fit substantially. Finally, we model the dust as a mixture of the most plausible debris constituents: astronomical silicates, water ice, organic refractory material, and vacuum. We achieve a good fit to all data sets with grains composed predominantly of silicates and organics, while ice and vacuum are, at most, present in small amounts. This composition is similar to one derived from previous work on the HR 4796A disk. Our model also fits the thermal spectral energy distribution, scattered light colors, and high-resolution mid-IR data from T-ReCS for this disk. Additionally, we show that sub-blowout grains are a necessary component of the halo.2016ApJ...823..108Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/823/108CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJS/211/25 : Spitzer/IRS debris disk catalog. I. (Chen+, 2014)J/ApJ/777/160 : NIR survey for planets around MG stars (Biller+, 2013)J/ApJ/775/55 : Spitzer IR excesses in A-K stars (Ballering+, 2013)J/ApJ/745/147 : Binaries among debris disk stars (Rodriguez+, 2012)J/A+A/542/A18 : {beta}Pic Harps radial velocity data (Lagrange+, 2012)J/PASP/119/994 : MIPS 24um calibrators (Engelbracht+, 2007)J/ApJ/660/1556 : Characterization of dusty debris disks (Rhee+, 2007)J/ApJ/653/675 : Spitzer 24{mu}m photometry of A dwarfs (Su+, 2006)J/ApJ/620/1010 : Spitzer 24{mu}m photometry of A dwarfs (Rieke+, 2005)J/MNRAS/304/733 : Beta Pictoris 1994-96 (Petterson+, 1999)J/A+A/299/557 : Light variations on Beta Pic (Lecavelier des Etangs+, 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/823/108https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/823/108http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/823/108https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/823/108https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/823/108http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/823/108GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/823/108/table3*Optical constants of the best fit model (60% Astronomical Silicates, 40% Organic Refractory Material);lambda[0.09/10000] Wavelengthumem.wldoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn[1.4/2.92] The n optical constantstat.fit.paramfloatk[0.008/0.86] The k optical constantstat.fit.paramfloat