J/A+A/635/A79ivo://CDS.VizieR/J/A+A/635/A79doi:10.26093/cds/vizier.36350079CDSCarcaboso F.Gomez-Herrero R.Espinosa Lara F.Hidalgo M.A.Cernuda I.,Rodriguez-Pacheco J.2020-09-03T13:30:50Z2020-03-10T11:42:56ZCDS support team

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

cds-question@unistra.frthe-sunsolar-systemSuprathermal electron pitch-angle distributions (PADs) contain substantial information about the magnetic topology of the solar wind. Their characterisation and quantification allow us to automatically identify periods showing certain characteristics. This work presents a robust automatic method for the identification and statistical study of two different types of PADs: bidirectional suprathermal electrons (BDE, often associated with closed magnetic structures) and isotropic (likely corresponding to solar-detached magnetic field lines or highly scattered electrons). Spherical harmonics were fitted to the observed suprathermal PADs of the 119-193eV energy channel of STEREO/SWEA from March 2007 to July 2014, and they were characterised using signal processing analysis in order to identify periods of isotropic and bidirectional PADs. The characterisation has been validated by comparing the results obtained here with those of previous studies. Interplanetary coronal mass ejections (ICMEs) present longer BDE periods inside the magnetic obstacles. A significant amount of BDE remain after the end of the ICME. Isotropic PADs are found in the sheath of the ICMEs, and at the post-ICME region likely due to the erosion of the magnetic field lines. Both isotropy and BDE are solar-cycle dependent. The isotropy observed by STEREO shows a nearly annual periodicity, which requires further investigation. There is also a correspondence between the number of ICMEs observed and the percentage of time showing BDE. A method to characterise PADs has been presented and applied to the automatic identification of two relevant distributions that are commonly observed in the solar wind, such as BDE and isotropy. Four catalogues (STEREO-A and STEREO-B for isotropic and BDE periods of at least 10min) based on this identification are provided for future applications.2020A&A...635A..79Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/635/A79CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/635/A79https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/635/A79http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/635/A79https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/635/A79https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/635/A79http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/635/A79GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/635/A79/bidirstaBidirectional periods in solar wind observed by STEREO-A (2007-03-03, 2014-07-16)CatCatalogued (1)meta.notecharBeta? Plasma betaphot.colorfloatnullablee_Beta? Plasma beta errorstat.errorfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObs.beginBeginning date (UTC)stime.startnullableObs.endEnd date (UTC)stime.endnullableDurTime durationmintime.durationfloatB? Magnetic fieldnTphys.magFieldfloatnullablee_B? Magnetic field errornTstat.errorfloatnullableRipple? Anisotropy index gamm%stat.fit.paramfloatnullablee_Ripple? Anisotropy index gamma error%stat.errorfloatnullableSNR24? SNR24 index, in dB unitstat.fit.paramfloatnullablee_SNR24? SNR24 index error, in dB unitstat.errorfloatnullableTp? Proton temperatureKphys.temperaturedoublenullablee_Tp? Proton temperature errorKstat.errordoublenullableVsw? Solar wind speedkm/sphys.velocfloatnullablee_Vsw? Solar wind speed errorkm/sstat.errorfloatnullableJ/A+A/635/A79/bidirstbBidirectional periods in solar wind observed by STEREO-B (2007-03-01, 2014-07-29)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObs.beginBeginning date (UTC)stime.startnullableObs.endEnd date (UTC)stime.endnullableDurTime durationmintime.durationfloatCatCatalogued (1)meta.notecharB? Magnetic fieldnTphys.magFieldfloatnullablee_B? Magnetic field errornTstat.errorfloatnullableBeta? Plasma betaphot.colorfloatnullablee_Beta? Plasma beta errorstat.errorfloatnullableRipple? Anisotropy index gamm%stat.fit.paramfloatnullablee_Ripple? Anisotropy index gamma error%stat.errorfloatnullableSNR24? SNR24 index, in dB unitstat.fit.paramfloatnullablee_SNR24? SNR24 index error, in dB unitstat.errorfloatnullableTp? Proton temperatureKphys.temperaturedoublenullablee_Tp? Proton temperature errorKstat.errordoublenullableVsw? Solar wind speedkm/sphys.velocfloatnullablee_Vsw? Solar wind speed errorkm/sstat.errorfloatnullableJ/A+A/635/A79/isostaIsotropic periods in solar wind observed by STEREO-A (2007-03-01, 2014-07-31)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObs.beginBeginning date (UTC)stime.startnullableObs.endEnd date (UTC)stime.endnullableDurTime durationmintime.durationfloatCatCatalogued (1)meta.notecharB? Magnetic fieldnTphys.magFieldfloatnullablee_B? Magnetic field errornTstat.errorfloatnullableBeta? Plasma betaphot.colorfloatnullablee_Beta? Plasma beta errorstat.errorfloatnullableRipple? Anisotropy index gamm%stat.fit.paramfloatnullablee_Ripple? Anisotropy index gamma error%stat.errorfloatnullableSNR24? SNR24 index, in dB unitstat.fit.paramfloatnullablee_SNR24? SNR24 index error, in dB unitstat.errorfloatnullableTp? Proton temperatureKphys.temperaturedoublenullablee_Tp? Proton temperature errorKstat.errordoublenullableVsw? Solar wind speedkm/sphys.velocfloatnullablee_Vsw? Solar wind speed errorkm/sstat.errorfloatnullableJ/A+A/635/A79/isostbIsotropic periods in solar wind observed by STEREO-B (2007-03-01, 2014-07-29)Tp? Proton temperatureKphys.temperaturedoublenullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObs.beginBeginning date (UTC)stime.startnullableObs.endEnd date (UTC)stime.endnullableDurTime durationmintime.durationfloatCatCatalogued (1)meta.notecharB? Magnetic fieldnTphys.magFieldfloatnullablee_B? Magnetic field errornTstat.errorfloatnullableBeta? Plasma betaphot.colorfloatnullablee_Beta? Plasma beta errorstat.errorfloatnullableRipple? Anisotropy index gamm%stat.fit.paramfloatnullablee_Ripple? Anisotropy index gamma error%stat.errorfloatnullableSNR24? SNR24 index, in dB unitstat.fit.paramfloatnullablee_SNR24? SNR24 index error, in dB unitstat.errorfloatnullablee_Tp? Proton temperature errorKstat.errordoublenullableVsw? Solar wind speedkm/sphys.velocfloatnullablee_Vsw? Solar wind speed errorkm/sstat.errorfloatnullable