J/A+A/654/A20ivo://CDS.VizieR/J/A+A/654/A20doi:10.26093/cds/vizier.36540020CDSGroenewegen M.A.T2022-09-07T06:58:05Z2021-10-01T08:25:55ZCDS support team

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

cds-question@unistra.frstellar-distancevisible-astronomytrigonometric-parallaxThe second data release of Gaia revealed a parallax zero-point offset of -0.029mas based on quasars. The value depended on the position on the sky, and also likely on magnitude and colour. The offset and its dependence on other parameters inhibited improvement in the local distance scale using for example the Cepheid and RR Lyrae period-luminosity relations. Analysis of the recent Gaia Early Data Release 3 (EDR3) reveals a mean parallax zero-point offset of -0.021 mas based on quasars. The Gaia team addresses the parallax zero-point offset in detail and proposes a recipe to correct for it based on ecliptic latitude, G-band magnitude, and colour information. This paper presents a completely independent investigation into this issue focusing on the spatial dependence of the correction based on quasars and the magnitude dependence based on wide binaries. The spatial and magnitude corrections are connected to each other in the overlap region in the range 17<G<19. The spatial correction is presented at several spatial resolutions based on the HEALPix formalism. The colour dependence of the parallax offset is unclear and in any case secondary to the spatial and magnitude dependence. The spatial and magnitude corrections are applied to two samples of brighter sources, namely a sample of approximately 100 stars with independent trigonometric parallax measurements from Hubble Space Telescope data, and a sample of 75 classical cepheids using photometric parallaxes. The mean offset between the observed GEDR3 parallax and the independent trigonometric parallax (excluding outliers) is about -39{mu}as, and after applying the correction it is consistent with being zero. For the classical cepheid sample the analysis presented here suggests that the photometric parallaxes may be underestimated by about 5%.2021A&A...654A..20Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/654/A20CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/654/A20https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/654/A20http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/654/A20https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/654/A20https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/654/A20http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/654/A20GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/654/A20/table1 (Stars with independent trigonometric parallaxes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/654/A20/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/654/A20/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/654/A20/table1?GETtext/xml+votable180.050000true3.86988-16.136571940.0055555555555555566/472 928 1431 1477 1694 2472 3344 3600 3751 4095 4244 4376 4790 5009 6340 6883 6974 7132 7518 8357 8917 9084 10002 10027 10169 10799 12187 12454 12859 12983 13201 13829 14018 14409 14679 14772 15036 15106 15220 15633 15658 15714 15842 16213 16827 17790 18496 19383 20618 22148 22878 23013 23503 23527 23537 23539 23547-23548 23922 24411 26446 27128 27730 27982 28779 28831 29095 29104 29451 29596 30315 30327 30553 31374 31447 31781 32074 32781 33804 36697 36919 37235 37303 38022 38919 39675 39908 39933 40167 40988 41591 43606 43947 44281 44518 44542 45720 47100 48034 48545 48985https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/654/A20?format=asciiOpticaldefaultJ/A+A/654/A20/table1Stars with independent trigonometric parallaxesSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameIdentifiermeta.id;meta.maincharplxParallaxmaspos.parallax.trigfloate_plxParallax errormasstat.error;pos.parallaxfloatr_plxParallax reference (1)meta.ref;pos.frameintRA_ICRSRight Ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainf_RA_ICRS[)] ) for position not in (ICRS) at Ep=2016.0meta.codecharDE_ICRSDeclination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainf_DE_ICRS[)] ) for position not in (ICRS) at Ep=2016.0meta.codecharGaiaEDR3? GAIA EDR3 Source Idmeta.idnullableplxG? GAIA parallaxmaspos.parallax.trigfloatnullablee_plxG? GAIA parallax errormasstat.errorfloatnullableGoF? GAIA Goodness-of-fitstat.fit.goodnessfloatnullableRUWE? GAIA RUWEmeta.code.qualfloatnullableGmag? GAIA G-band magnitudemagphot.mag;em.optfloatnullablee_Gmag? GAIA G-band magnitude errormagstat.error;phot.magfloatnullableBP-RP? GAIA (G_BP_-G_RP_) colourmagphot.color;em.opt.B;em.opt.Rfloatnullablee_BP-RP? GAIA (G_BP_-G_RP_) colourmagstat.errorfloatnullable_RA.icrsRight ascension (ICRS) at Epoch=J2016. (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=J2016. (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.decnullableindexedJ/A+A/654/A20/m30Parallax zero-point offset for Model 30recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpixelHEALPix pixel numbermeta.numberintPZPOParallax zeropoint offset (1)masstat.fit;arith.zpdoublee_PZPOError in the PZPOmasstat.errordoubleNNumber of objects in that pixelmeta.numberintJ/A+A/654/A20/m31Parallax zero-point offset for Model 31recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpixelHEALPix pixel numbermeta.numberintPZPOParallax zeropoint offset (1)masstat.fit;arith.zpdoublee_PZPOError in the PZPOmasstat.errordoubleNNumber of objects in that pixelmeta.numberintJ/A+A/654/A20/m32Parallax zero-point offset for Model 32recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpixelHEALPix pixel numbermeta.numberintPZPOParallax zeropoint offset (1)masstat.fit;arith.zpdoublee_PZPOError in the PZPOmasstat.errordoubleNNumber of objects in that pixelmeta.numberintJ/A+A/654/A20/m33Parallax zero-point offset for Model 33recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpixelHEALPix pixel numbermeta.numberintPZPOParallax zeropoint offset (1)masstat.fit;arith.zpdoublee_PZPOError in the PZPOmasstat.errordoubleNNumber of objects in that pixelmeta.numberintJ/A+A/654/A20/m34Parallax zero-point offset for Model 34pixelHEALPix pixel numbermeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPZPOParallax zeropoint offset (1)masstat.fit;arith.zpdoublee_PZPOError in the PZPOmasstat.errordoubleNNumber of objects in that pixelmeta.numberintJ/A+A/654/A20/m35Parallax zero-point offset for Model 35recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpixelHEALPix pixel numbermeta.numberintPZPOParallax zeropoint offset (1)masstat.fit;arith.zpdoublee_PZPOError in the PZPOmasstat.errordoubleNNumber of objects in that pixelmeta.numberintJ/A+A/654/A20/m36Parallax zero-point offset for Model 36recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpixelHEALPix pixel numbermeta.numberintPZPOParallax zeropoint offset (1)masstat.fit;arith.zpdoublee_PZPOError in the PZPOmasstat.errordoubleNNumber of objects in that pixelmeta.numberintJ/A+A/654/A20/m37Parallax zero-point offset for Model 37pixelHEALPix pixel numbermeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPZPOParallax zeropoint offset (1)masstat.fit;arith.zpdoublee_PZPOError in the PZPOmasstat.errordoubleNNumber of objects in that pixelmeta.numberintJ/A+A/654/A20/m38Parallax zero-point offset for Model 38recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpixelHEALPix pixel numbermeta.numberintPZPOParallax zeropoint offset (1)masstat.fit;arith.zpdoublee_PZPOError in the PZPOmasstat.errordoubleNNumber of objects in that pixelmeta.numberintJ/A+A/654/A20/m39Parallax zero-point offset for Model 39recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpixelHEALPix pixel numbermeta.numberintPZPOParallax zeropoint offset (1)masstat.fit;arith.zpdoublee_PZPOError in the PZPOmasstat.errordoubleNNumber of objects in that pixelmeta.numberint