J/ApJS/246/4ivo://CDS.VizieR/J/ApJS/246/4doi:10.26093/cds/vizier.22460004CDSTian H.-J.El-Badry K.Rix H.-W.Gould A.2020-11-12T09:04:01Z2020-04-20T13:35:07ZCDS support team

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

cds-question@unistra.frmultiple-starsastrometryphotometryvisible-astronomyradial-velocityWe present an extensive and pure sample of ultrawide binary stars with separations of 0.01<~s/pc<~1 in the solar neighborhood. Using data from Gaia DR2, we define kinematic subpopulations via the systems' tangential velocities, i.e., disk-like (v_{perp},tot_<=40km/s), intermediate (v_{perp},tot_=40-85km/s), and halo-like (v_{perp},tot_>=85km/s) binaries, presuming that these velocity cuts represent a rough ordering in the binaries' age and metallicity. Through stringent cuts on astrometric precision, we can obtain pure binary samples at such wide separations with thousands of binaries in each sample. Fitting a smoothly broken power law for the separation distribution, we find that its slope at s=10^2.5-4^au is the same for all subpopulations, p(s){propto}s^{gamma}^ with {gamma}~-1.54. However, the logarithmic slope of p(s) steepens at s>~10^4^au. We find some evidences that the degree of steepening increases with the binaries' age, with a slope change of only {Delta}{gamma}~0.5 for disk-like stars, but {Delta}{gamma}>~1 for halo-like stars. This trend is contrary to what might be expected if steepening at wide separations were due to gravitational perturbations by molecular clouds or stars, which would preferentially disrupt disk binaries. If we were to interpret steepening at s>~10^4^au as a consequence of disruption by MAssive Compact Halo Objects (MACHOs), we would have to invoke a MACHO population inconsistent with other constraints. As a more plausible alternative, we propose a simple model to predict the separation distribution of wide binaries formed in dissolving star clusters. This model generically predicts {gamma}~-1.5 as observed, with steepening at larger separations due to the finite size of binaries' birth clusters.2020ApJS..246....4Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/246/4CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)J/AJ/133/889 : Faint companions of Hipparcos stars (Lepine+, 2007)J/AJ/139/2566 : SLoWPoKES catalog (Dhital+, 2010)J/ApJ/790/158 : Candidate halo wide binaries (Allen+, 2014)J/MNRAS/472/675 : Wide binaries in Tycho-Gaia: search method (Andrews+, 2017)J/AJ/153/259 : The GAMBLES extension of the SLoWPoKES cat. (Oelkers+, 2017)J/AJ/155/149 : Co-moving stars observed by Gaia (Bochanski+, 2018)J/AJ/156/259 : Robo-AO detected close binaries in Gaia DR2 (Ziegler+, 2018)J/AJ/157/78 : Multiple star systems from GaiaDR2 (Jimenez-Esteban+, 2019)J/other/JDSO/15.434 : New Binary Systems from Data of Gaia DR2 (Romanov, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/246/4https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/246/4http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/246/4https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/246/4https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/246/4http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/246/4GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/246/4/catalog (Catalog of all candidate wide binaries (a<1pc) selected from Gaia DR2 in the solar neighborhood with distances d<4kpc)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/246/4/catalog?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/246/4/catalog?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/246/4/catalog?GETtext/xml+votable180.050000true281.300809338-29.68409925470.0055555555555555560/0 2 4 5 8 1/4 6 7 14 24 25 30 38 39 42 43 44 45 46 2/22 23 48 49 51 52 53 55 60 62 63 104 105 106 109 116 117 118 124 126 127 144 145 147 149 150 151 160 161 166 167 188 189 190 3/80 82 83 84 86 87 200 201 202 216 217 218 244 247 428 429 430 432 433 434 440 442 443 446 447 448 452 453 455 456 458 459 462 463 477 501 502 503 584 585 586 593 594 595 648 651 653 654 655 656 657 658 660 661 764 765 766 4/324 325 326 340 342 343 812 813 815 876 877 879 980 982 983 985 986 987 1725 1726 1727 1740 1741 1743 1764 1765 1766 1776 1777 1779 1780 1781 1782 1796 1797 1798 1801 1802 1804 1805 1816 1828 1829 1841 1842 1843 1844 1846 1847 1904 1906 1907 1912 1913 1914 1916 1917 2000 2002 2003 2348 2349 2350 2368 2370 2371 2596 2597 2599 2600 2602 2603 2608 2610 2611 2636 2638 2639 2648 2649 2650 2652 2653 2654 3068 3069 3070 5/1308 1310 1311 1365 1366 1367 3924 3925 3926 3936 6896 6897 6898 6968 6969 6970 7068 7069 7070 7112 7113 7115 7132 7133 7134 7200 7201 7202 7212 7213 7215 7224 7225 7226 7228 7230 7231 7268 7269 7270 7272 7273 7274 7320 7321 7322 7324 7326 7327 7361 7362 7363 7380 7381 7660 7662 7672 7676 7677 7678 8004 8005 8006 9404 9405 9477 9478 9479 10392 10393 10395 10404 10407 10436 10437 10438 10548 10549 10551 10604 10605 10607 10620 10621 10622 12284 12285 12286 6/5236 5237 5238 5457 5458 5459 13024 13025 14048 14049 14050 15708 15709 27597 27598 27599 27884 27885 27887 28285 28286 28287 28456 28457 28459 28541 28542 28543 28784 28785 28812 28814 28815 28857 28858 28859 28908 28910 28916 28917 28919 29085 29086 29087 29100 29101 29104 29105 29292 29294 29295 29301 29302 29303 29441 29442 29443 30480 30481 30482 30645 30646 30647 30652 30653 30655 30692 30693 30717 30718 30719 32029 32030 32031 37624 37904 37906 37907 41576 41578 41579 41621 41622 41623 41624 41626 41757 41758 41759 42200 42201 42202 42424 42425 42426 42493 42494 42495 49148 49149 49150https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/246/4?format=asciiOpticaldefaultJ/ApJS/246/4/catalogCatalog of all candidate wide binaries (a<1pc) selected from Gaia DR2 in the solar neighborhood with distances d<4kpcrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaia2Gaia DR2 identifier of Star 2 (785,036 uniques) (source_id2)meta.id.assocRA2degGaia DR2 barycentric right ascension (ICRS) at Ep=2015.5 of Star 2 (ra2)degpos.eq.raDE2degGaia DR2 barycentric declination (ICRS) at Ep=2015.5 of Star 2 (dec2)degpos.eq.decchi2AL2[22/135246] Star 2 astrometric goodness of fit ({chi}^2^) in the along-scan direction (astrometric_chi2_al_2)stat.fit.goodness;pos.dirCosdoubleNgAL2[44/1100] Star 2 number of good CCD transits (astrometric_n_good_obs_al2)meta.numberintRFG2[50/12061] Star 2 G-band mean flux divided by its error (phot_g_mean_flux_over_error2)stat.fit.omcdoubleRFRP2[10/192345] Star 2 integrated RP mean flux divided by its error (phot_rp_mean_flux_over_error2)stat.fit.omcdoubleRFBP2[10/73309] Star 2 integrated BP mean flux divided by its error (phot_bp_mean_flux_over_error2)stat.fit.omcdoubleE(BR/RP)2[1/2.5] Star 2 BP/RP excess factor (phot_bp_rp_excess_factor2)phot.color.excessfloatpmRA2[-2251/4106] Star 2 proper motion in right ascension direction (pmRA*cosDE) (pmra2)mas/yrpos.pm;pos.eq.radoublee_pmRA2[0.01/4.5] pmRA2 standard error (pmra_error2)mas/yrstat.error;pos.pm;pos.eq.rafloatpmDE2[-3541/3156] Star 2 proper motion in declination (pmdec2)mas/yrpos.pm;pos.eq.decdoublee_pmDE2[0.01/4] pmDE2 standard error (pmdec_error2)mas/yrstat.error;pos.pm;pos.eq.decfloatGmag2[3.2/21] Star 2 G-band mean magnitude (Vega) (phot_g_mean_mag2)magphot.mag;em.optfloatBPmag2[3.6/24.8] Star 2 integrated BP mean magnitude (Vega) (phot_bp_mean_mag2)magphot.mag;em.opt.BfloatRPmag2[2.7/21] Star 2 integrated RP mean magnitude (Vega) (phot_rp_mean_mag2)magphot.mag;em.opt.RfloatPlx2[0.2/286.2] Star 2 absolute parallax (parallax2)maspos.parallax.trigdoubleRPlx2[2/5416] Parallax divided by its error (parallax_over_error2)stat.error;pos.parallaxdoubleGaiaGaia DR2 identifier of Star 1 (782,120 uniques) (source_id)meta.id;meta.mainRA_ICRSGaia DR2 barycentric right ascension (ICRS) at Ep=2015.5 of Star 1 (ra)degpos.eq.ra;meta.mainindexedDE_ICRSGaia DR2 barycentric declination (ICRS) at Ep=2015.5 of Star 1 (dec)degpos.eq.dec;meta.mainindexedpmRA[-2241/4165] Star 1 proper motion in right ascension direction (pmRA*cosDE) (pmra)mas/yrpos.pm;pos.eq.radoublee_pmRA[0.01/1.2] pmRA1 standard error (pmra_error)mas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-3543/3250] Star 1 proper motion in declination (pmdec)mas/yrpos.pm;pos.eq.decdoublee_pmDE[0.01/1.3] pmDE1 standard error (pmdec_error)mas/yrstat.error;pos.pm;pos.eq.decfloatGmag[3.2/20.1] Star 1 G-band mean magnitude (Vega) (phot_g_mean_mag)magphot.mag;em.optfloatBPmag[3.6/21.2] Star 1 integrated BP mean magnitude (Vega) (phot_bp_mean_mag)magphot.mag;em.opt.BfloatRPmag[2.6/19.3] Star 1 integrated RP mean magnitude (Vega) (phot_rp_mean_mag)magphot.mag;em.opt.RfloatPlx[0.2/286] Star 1 absolute parallax (parallax)maspos.parallax.trigdoubleRPlx[20/6543] Parallax divided by its error (parallax_over_error)stat.error;pos.parallaxdoublechi2AL[15/189370] Star 1 astrometric goodness of fit ({chi}^2^) in the along-scan direction (astrometric_chi2_al)stat.fit.goodness;pos.dirCosdoubleNgAL[45/1089] Star 1 number of good CCD transits (astrometric_n_good_obs_al)meta.numberintRFG[60/13735] Star 1 G-band mean flux divided by its error (phot_g_mean_flux_over_error)stat.fit.omcdoubleRFRP[20/842507] Star 1 integrated RP mean flux divided by its error (phot_rp_mean_flux_over_error)stat.fit.omcdoubleRFBP[20/5104061] Star 1 integrated BP mean flux divided by its error (phot_bp_mean_flux_over_error)stat.fit.omcdoubleE(BR/RP)[1/2.1] Star 1 BP/RP excess factor (phot_bp_rp_excess_factor)phot.color.excessfloatSepdeg[0.0003/1.1] Angular separation between star 1 and star 2 (pairdistance)degpos.angDistancedoubleSepau[10.9/201600] Projected physical separation between two stars (s_AU)aupos.angDistancedoubleNp[1/9] Number of pairs in neighborhood for each binary (num)meta.numberintType[1/3] Type of wide binary (binary_type) (1)meta.codeintGLONStar 1 galactic longitude (gl)degpos.galactic.lonGLATStar 1 galactic latitude (gb)degpos.galactic.latdoubleGLON2Star 2 galactic longitude (gl2)degpos.galactic.lonGLAT2Star 2 galactic latitude (gb2)degpos.galactic.latdoubleSep[1.2/3858] Angular separation between the two stars (theta)arcsecpos.angDistancedoublee_dmu[0.02/1.5] dmu uncertainty (sig_dmu)mas/yrstat.errorfloatdmu[0.0003/184] Total scalar difference in proper motions between the two stars ({Delta}{mu}) (see Section 2.1)mas/yrpos.pm;arith.diffdoubledmuOrb[0.008/821] Maximum proper-motion difference permissible for a circular orbit of total mass 5M_{sun}_ (dmu_orbit)mas/yrpos.pm;arith.diffdoubleGMag2[-5.2/16] Star 2 absolute G-band magnitude (MG2)magphys.magAbsfloatGMag[-3/16] Star 1 absolute G-band magnitude (MG)magmeta.idfloatRV2[-325/725]? Star 2 spectroscopic barycentric radial velocity (radial_velocity2)km/sphys.veloc;pos.barycenterfloatnullablee_RV2[0.1/20]? RV2 standard error (radial_velocity_error2)km/sstat.errorfloatnullableRV[-716/565]? Star 1 spectroscopic barycentric radial velocity (radial_velocity)km/sphys.veloc;pos.barycenterfloatnullablee_RV[0.1/20]? RV1 standard error (radial_velocity_error)km/sstat.errorfloatnullableUGaia[-290/547]? Star 1 radial velocity in the Cartesian coordinates (positive to the Galactic center) (U_gaia)km/sphys.veloc;pos.cartesian.xdoublenullableVGaia[-498/652]? Star 1 azimuthal velocity in the Cartesian coordinates (V_gaia)km/sphys.veloc;pos.cartesian.ydoublenullableWGaia[-255/338]? Star 1 vertical velocity in the Cartesian coordinates (W_gaia)km/sphys.veloc;pos.cartesian.zdoublenullablee_UGaia[0.03/25]? UGaia error (eU_gaia)km/sstat.errorfloatnullablee_VGaia[0.03/20]? VGaia error (eV_gaia)km/sstat.errorfloatnullablee_WGaia[0.02/20]? WGaia error (eW_gaia)km/sstat.errorfloatnullableUGaia2[-534/335]? Star 2 radial velocity in the Cartesian coordinates (positive to the Galactic center) (U_gaia2)km/sphys.veloc;pos.cartesian.xdoublenullableVGaia2[-500/532]? Star 2 azimuthal velocity in the Cartesian coordinates (V_gaia2)km/sphys.veloc;pos.cartesian.ydoublenullableWGaia2[-381/175]? Star 2 vertical velocity in the (W_gaia2)km/sphys.veloc;pos.cartesian.zdoublenullablee_UGaia2[0.05/20]? UGaia2 error (eU_gaia2)km/sstat.errorfloatnullablee_VGaia2[0.03/20]? VGaia2 error (eV_gaia2)km/sstat.errorfloatnullablee_WGaia2[0.04/19]? WGaia2 error (eW_gaia2)km/sstat.errorfloatnullablePop[dhi ] Binary kinematic subpopulation; column added by CDS (2)meta.codechar_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decnullableindexed