J/ApJ/933/54ivo://CDS.VizieR/J/ApJ/933/54doi:10.26093/cds/vizier.19330054CDSLu C.X.Chen C.H.Sargent B.A.Watson D.M.Lisse C.M.Green J.D.,Sitko M.L.Mittal T.Lebouteiller V.Sloan G.C.Rebollido I.,Hines D.C.Girard J.H.Werner M.W.Stapelfeldt K.R.Wu W.Worthen K.2025-02-12T20:09:03Z2024-10-09T14:20:00ZCDS support team

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

cds-question@unistra.frvisible-astronomyspectroscopyinfrared-astronomya-starsexoplanetsWhile {beta} Pic is known to host silicates in ring-like structures, whether the properties of these silicate dust vary with stellocentric distance remains an open question. We re-analyze the {beta} Pictoris debris disk spectrum from the Spitzer Infrared Spectrograph (IRS) and a new Infrared Telescope Facility Spectrograph and Imager spectrum to investigate trends in Fe/Mg ratio, shape, and crystallinity in grains as a function of wavelength, a proxy for stellocentric distance. By analyzing a re-calibrated and re-extracted spectrum, we identify a new 18um forsterite emission feature and recover a 23um forsterite emission feature with a substantially larger line-to-continuum ratio than previously reported. We find that these prominent spectral features are primarily produced by small submicron-sized grains, which are continuously generated and replenished from planetesimal collisions in the disk and can elucidate their parent bodies' composition. We discover three trends about these small grains: as stellocentric distance increases, (1) small silicate grains become more crystalline (less amorphous), (2) they become more irregular in shape, and (3) for crystalline silicate grains, the Fe/Mg ratio decreases. Applying these trends to {beta} Pic's planetary architecture, we find that the dust population exterior to the orbits of {beta} Pic b and c differs substantially in crystallinity and shape. We also find a tentative 3-5um dust excess due to spatially unresolved hot dust emission close to the star. From our findings, we infer that the surfaces of large planetesimals are more Fe-rich and collisionally processed closer to the star but more Fe-poor and primordial farther from the star.2022ApJ...933...54Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/933/54CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-)B/gemini : The Gemini Observation Log (CADC, 2001-)VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)J/A+AS/114/247 : Limb-darkening coefficients for R I J H K (Claret+, 1995)J/A+A/363/1081 : Non-linear limb-darkening law for LTE models (Claret 2000)J/ApJS/154/673 : COBE DIRBE Point Source Catalog (Smith+, 2004)J/ApJ/653/675 : Spitzer 24um photometry of A dwarfs (Su+, 2006)J/PASP/122/162 : Direct imaging of exoplanets (Beichman+, 2010)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/A+A/552/A119 : Planet-star and moon-planet interaction (Saur+, 2013)J/ApJ/777/160 : NIR imaging survey for planets around MG stars (Biller+, 2013)J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)J/ApJS/211/25 : Spitzer/IRS debris disk catalog. I. (Chen+, 2014)J/ApJ/798/87 : Spitzer/IRS debris disk catalog. II. (Mittal+, 2015)J/AJ/149/11 : Spectra of candidate standard stars in mid-IR (Sloan+, 2015)J/MNRAS/449/3160 : Stellar multiplicity and debris discs (Rodriguez+, 2015)J/ApJ/823/108 : A dust model for bet Pic from 0.58 to 870um (Ballering+, 2016)J/ApJ/826/171 : IR data of debris disk vs metallicity of stars (Gaspar+, 2016)J/ApJS/225/15 : IR excess stars from Tycho-2 and AllWISE (Cotten+, 2016)J/A+A/594/A59 : Far-IR lines in YSOs Herschel-PACS (Riviere-Marichalar+, 2016)J/A+A/595/A31 : SAM detection limits of 8 debris disks (Gauchet+, 2016)J/A+A/607/A25 : beta Pic HARPS spectrum (Vidal-Madjar+, 2017)J/AJ/154/245 : Spitzer-detected debris disks (Meshkat+, 2017)J/MNRAS/469/521 : CO gas content of debris discs predictions (Kral+, 2017)J/ApJS/239/14 : Revised exoplanet radii from Gaia DR2 (Johns+, 2018)J/A+A/627/A28 : beta Pic BRITE, bRing, SMEI light curves (Zwintz+, 2019)J/A+A/625/L13 : TESS light curve of beta Pictoris (Zieba+, 2019)J/A+A/633/A110 : K band spectrum of beta Pictoris b (GRAVITY+, 2020)J/A+A/648/A15 : beta Pictoris photometry (Kenworthy+, 2021)J/A+A/646/A132 : beta Pictoris debris disk image (Janson+, 2021)J/A+A/657/A7 : Stellar & substellar companions from Gaia (Kervella+, 2022)J/AJ/161/179 : Predicted positions of {beta}Pictoris b and c (Brandt+, 2021)J/A+A/672/A114 : FITS images of HST debris disks (Ren+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/933/54https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/933/54http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/933/54https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/933/54https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/933/54http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/933/54GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/ApJ/933/54/fig2List of FITS files; table added by CDSrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFileName of the FITS file in subdirectory "sp"meta.id;meta.fitscharInstInstrument identifier ("IRTF" or "IRS")meta.id;instrcharlam1Wavelength lower rangeumem.wl;stat.minfloatlam2Wavelength upper rangeumem.wl;stat.maxfloatDateObservation date (UT)time.epoch;obsnullablespInteractive spectrum plotmeta.ref.urlcharfitsDownload the FITS filemeta.ref.urlchar