I/348ivo://CDS.VizieR/I/348CDSMackereth J.T.Bovy J.2019-01-07T08:49:30Z2018-11-20T15:22:06ZCDS support team

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

cds-question@unistra.frmilky-way-galaxystellar-populationsastrometryastronomical-modelsOrbital parameters, such as eccentricity and maximum vertical excursion, of stars in the Milky Way are an important tool for understanding its dynamics and evolution, but calculation of such parameters usually relies on computationally-expensive numerical orbit integration. We present and test a fast method for estimating these parameters using an application of the Sackel fudge, used previously for the estimation of action-angle variables. We show that the method is highly accurate, to a level of <1% in eccentricity, over a large range of relevant orbits and in different Milky Way-like potentials, and demonstrate its validity by estimating the eccentricity distribution of the RAVE-TGAS data set and comparing it to that from orbit integration. Using the method, the orbital characteristics of the ~7 million Gaia DR2 stars with radial velocity measurements are computed with Monte Carlo sampled errors in ~116 hours of parallelised cpu time, at a speed that we estimate to be ~3 to 4 orders of magnitude faster than using numerical orbit integration. We demonstrate using this catalogue that Gaia DR2 samples a large range of orbits in the solar vicinity, down to those with r_peri_<~2.5kpc, and out to r_ap_>~13kpc. We also show that many of the features present in orbital parameter space have a low mean zmax, suggesting that they likely result from disk dynamical effects.2018PASP..130k4501Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/I/348CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/337 : Gaia DR1 (Gaia Collaboration, 2016)I/345 : Gaia DR2 (Gaia Collaboration, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=I/348https://vizier.iucaa.in/viz-bin/VizieR-2?-source=I/348http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=I/348https://vizier.cds.unistra.fr/viz-bin/votable?-source=I/348https://vizier.iucaa.in/viz-bin/votable?-source=I/348http://vizieridia.saao.ac.za/viz-bin/votable?-source=I/348GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table I/348/catalog (Catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/I/348/catalog?https://vizier.iucaa.in/viz-bin/conesearch/I/348/catalog?http://vizieridia.saao.ac.za/viz-bin/conesearch/I/348/catalog?GETtext/xml+votable180.050000true45.13214374784830.1378509659840.0055555555555555560/0 1 2 3 4 5 6 7 8 9 10 11https://cdsarc.cds.unistra.fr/viz-bin/moc/I/348?format=asciidefaultI/348/catalogCatalogJR? Radial action (jr)kpc.km/sarith.grad;phys.velocdoublenullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceGaia DR2 source ID (source_id)meta.id;meta.mainRA_ICRSGaia barycentric right ascension (ICRS) at Ep=2015.5 (ra)degpos.eq.ra;meta.mainindexedDE_ICRSGaia barycentric declination (ICRS) at Ep=2015.5 (dec)degpos.eq.dec;meta.mainindexede? Orbital eccentricity as defined in Equation (10) (e)src.orbital.eccentricitydoublenullablee_e? rms uncertainty on e (e_err)stat.errordoublenullablezmax? maximum vertical excursion from the midplane (zmax)kpcpos.cartesian.z;pos.galacticdoublenullablen_zmax[iI] i for -inf I for infmeta.notechare_zmax? rms uncertainty on zmax (zmax_err)kpcstat.errordoublenullablerperi? 3D pericenter radius (rperi)kpcphys.size.radiusdoublenullablen_rperi[iI] i for -inf I for infmeta.notechare_rperi? rms uncertainty on rperi (rperi_err)kpcstat.errordoublenullablerap? 3D apocenter radius (rap)kpcphys.size.radiusdoublenullablen_rap[iI] i for -inf I for infmeta.notechare_rap? rms uncertainty on rap (rap_err)kpcstat.errordoublenullableezmaxCor? Correlation between e and zmax (e_zmax_corr) (1)stat.correlationdoublenullableerperiCor? Correlation between e and rperi (e_rperi_corr) (1)stat.correlationdoublenullableerapCor? Correlation between e and rap (e_rap_corr) (1)stat.correlationdoublenullablezmaxrperiCor? Correlation between zmax and rperi (zmax_rperi_corr) (1)stat.correlationdoublenullablezmaxrapCor? Correlation between zmax and rap (zmax_rap_corr) (1)stat.correlationdoublenullablerperirapCor? Correlation between rperi and rap (rperi_rap_corr) (1)stat.correlationdoublenullablee_JR? rms uncertainty on JR (jr_err)kpc.km/sstat.errordoublenullableLz? Azimuthal action (equivalent to vertical component of angular momentum) (Lz)kpc.km/sphys.angMomentumdoublenullablee_Lz? rms uncertainty on Lz (Lz_err)kpc.km/sstat.errordoublenullableJZ? Vertical action (jz)kpc.km/sarith.grad;phys.velocdoublenullablee_JZ? rms uncertainty on JZ (jz_err)kpc.km/sstat.errordoublenullableJRLZCor? Correlation between JR and LZ (jr_Lz_corr) (1)stat.correlationdoublenullableJRJZCor? Correlation between JR and JZ (jr_jz_corr) (1)stat.correlationdoublenullableLZJZCor? Correlation between LZ and JZ (lz_jz_corr) (1)stat.correlationdoublenullableomegaR? Radial frequency (omega_r)Gyr**-1pos.ephemdoublenullablen_omegaR[i] i for infinitymeta.notechare_omegaR? rms uncertainty on omegaR (omega_r_err)Gyr**-1stat.errordoublenullableomegaphi? Azimuthal frequency (omega_phi)Gyr**-1pos.ephemdoublenullablee_omegaphi? rms uncertainty on omegaphi (omega_phi_err)Gyr**-1stat.errordoublenullableomegaz? Vertical frequency (omega_z)Gyr**-1pos.ephemdoublenullablen_omegaz[i] i for infinitymeta.notechare_omegaz? rms uncertainty on omegaz (omega_z_err)Gyr**-1stat.errordoublenullablethetaR? Radial angle (theta_r)radpos.posAngdoublenullablee_thetaR? rms uncertainty on thetaR (theta_r_err)radstat.errordoublenullablethetaphi? Azimuthal angle (theta_phi)radpos.posAngdoublenullablee_thetaphi? rms uncertainty on thetaphi (theta_phi_err)radstat.errordoublenullablethetaz? Vertical angle (theta_z)radpos.posAngdoublenullablee_thetaz? rms uncertainty on thetaz (theta_z_err)radstat.errordoublenullableRguide? Radius of a circular orbit at the same Lz (rl)kpcphys.size.radiusdoublenullablee_Rguide? rms uncertainty on Rguide (rl_err)kpcstat.errordoublenullableE? Orbital energy (E)km**2.s**-2src.orbitaldoublenullablee_E? rms uncertainty on E (E_err)km**2.s**-2stat.errordoublenullableE-Ec? Difference between orbit energy and energy of a circular orbit of the same Lz (EminusEc)km**2.s**-2phys.energy;arith.diffdoublenullablee_E-Ec? rms uncertainty on E-Ec (EminusEc_err)km**2.s**-2stat.errordoublenullable_RA.icrsRight ascension (ICRS) at Epoch=J2015.5 (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2015.5 (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decnullableindexed