J/AJ/154/53ivo://CDS.VizieR/J/AJ/154/53doi:10.26093/cds/vizier.51540053CDSBauer J.M.Grav T.Fernandez Y.R.Mainzer A.K.Kramer E.A.,Masiero J.R.Spahr T.Nugent C.R.Stevenson R.A.Meech K.J.,Cutri R.M.Lisse C.M.Walker R.Dailey J.W.Rosser J.Krings P.,Ruecker K.Wright E.L.(the NEOWISE Team)2017-12-13T19:20:00Z2017-10-27T09:10:35ZCDS support team

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

cds-question@unistra.frsolar-systemcometsinfrared-sourcessurveysWe use NEOWISE data from the four-band and three-band cryogenic phases of the Wide-field Infrared Survey Explorer mission to constrain size distributions of the comet populations and debias measurements of the short- and long-period comet (LPC) populations. We find that the fit to the debiased LPC population yields a cumulative size-frequency distribution (SFD) power-law slope ({beta}) of -1.0+/-0.1, while the debiased Jupiter-family comet (JFC) SFD has a steeper slope with {beta}=-2.3+/-0.2. The JFCs in our debiased sample yielded a mean nucleus size of 1.3km in diameter, while the LPCs' mean size is roughly twice as large, 2.1km, yielding mean size ratios (<D_LPC_>/<D_JFC_>) that differ by a factor of 1.6. Over the course of the 8 months of the survey, our results indicate that the number of LPCs passing within 1.5 au are a factor of several higher than previous estimates, while JFCs are within the previous range of estimates of a few thousand down to sizes near 1.3km in diameter. Finally, we also observe evidence for structure in the orbital distribution of LPCs, with an overdensity of comets clustered near 110{deg} inclination and perihelion near 2.9 au that is not attributable to observational bias.2017AJ....154...53Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/154/53CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/comets : Database of the orbital elements of comets (Rocher, 2007)II/311 : WISE All-Sky Data Release (Cutri+ 2012)J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)J/ApJ/760/L12 : WISE/NEOWISE NEOs preliminary thermal fits (Mainzer+, 2012)J/ApJ/759/L8 : Main belt asteroids WISE/NEOWISE observations (Masiero+, 2012)J/ApJ/759/49 : WISE/NEOWISE Jovian Trojan asteroids: taxonomy (Grav+, 2012)J/ApJ/744/197 : WISE/NEOWISE observations of Hilda asteroids (Grav+, 2012)J/ApJ/743/156 : NEOWISE obs. of NEOs: preliminary results (Mainzer+, 2011)J/ApJ/742/40 : Jovian Trojans asteroids with WISE/NEOWISE (Grav+, 2011)J/ApJ/741/68 : Main Belt asteroids with WISE/NEOWISE. I. (Masiero+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/154/53https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/154/53http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/154/53https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/154/53https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/154/53http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/154/53GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap8.157980699529898e-21 2.1279058820884434e-20InfrareddefaultJ/AJ/154/53/table1Comet observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypePeriod type (Short or Long)meta.notecharCometComet designationmeta.id;meta.maincharRhelio[2/12] Heliocentric distanceAUpos.distance;pos.heliocentricfloatDelta[1.73/11.85] Comet-spacecraft distance {Delta}AUpos.distancefloatSW3[0.05/410]? WISE W3 band (12{mu}m) band flux density (1)mJyphot.flux.density;em.IR.8-15umfloatnullablee_SW3[0.02/75]? Uncertainty in SW3mJystat.errorfloatnullableSW4[1.5/127]? WISE W4 band (22{mu}m) band flux density (1)mJyphot.flux.density;em.IR.15-30umfloatnullablee_SW4[0.5/24]? Uncertainty in SW4mJystat.errorfloatnullableActApparent activity? (Y=Yes, N=No, U=Uncertain) (2)meta.codecharMJDModified Julian Date of stacked image mid-exposuredtime.epochdoubleNfr[3/38] Number of frames co-added in stacked imagemeta.numberintJ/AJ/154/53/table2Coma subtraction model fit parametersBandWISE bandinstr.bandpasscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintModelModelmeta.noteintInt0? Starting value of the coma fit interval (1)arcsecpos.angDistancefloatnullableInt1? Ending value of the coma fit interval (1)arcsecpos.angDistancefloatnullablen_Int1Note about the coma fit intervalmeta.notecharComCommentsmeta.notecharJ/AJ/154/53/table3Diameters and {epsilon}f{rho}recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypePeriod type (Short or Long)meta.notecharCometComet designationmeta.id;meta.maincharprimaryf_Comet[*] Flag on Comet (1)meta.codecharObsindicates comet observations in Table1meta.ref.urlchareta[0.56/1.6]? Dimensionless beaming parameter {eta} (2)stat.fit.paramfloatnullablee_eta[0.02/0.85]? Uncertainty in etastat.error;phys.electron.degenfloatnullableDiam[0.43/201]? Diameterkmphys.size.diameterfloatnullablee_Diam[0.04/62]? Uncertainty in Diamkmstat.errorfloatnullablel_efrho[<] Upper limit flag on efrhometa.code.errorcharefrho[0/30]? Log emissivity-fractional area-comet centric distance {epsilon}f{rho} (3)log(cm)pos.distancefloatnullablee_efrho[0/5]? Uncertainty in {epsilon}f{rho}log(cm)stat.errorfloatnullableW3a[1/5]? Coma subtraction model for W3 band (4)meta.id;stat.fitintnullableW3b[2/4]? Coma subtraction model for W3 band (4)meta.id;stat.fitintnullableW3c[3/4]? Coma subtraction model for W3 band (4)meta.id;stat.fitintnullableW3d[4]? Coma subtraction model for W3 band (4)meta.id;stat.fitintnullabler_W3dReference where diameter fits were previously publishedmeta.ref;pos.framecharW4a[1/5]? Coma subtraction model for W4 band (4)meta.id;stat.fitintnullableW4b[2/4]? Coma subtraction model for W4 band (4)meta.id;stat.fitintnullableW4c[3/4]? Coma subtraction model for W4 band (4)meta.id;stat.fitintnullableW4d[4]? Coma subtraction model for W4 band (4)meta.id;stat.fitintnullabler_W4dReference where diameter fits were previously publishedmeta.ref;pos.framecharComAdditional comments regarding fits and signalstat.snr;meta.fitschar