J/A+A/645/A124ivo://CDS.VizieR/J/A+A/645/A124doi:10.26093/cds/vizier.36450124CDSGehan C.Mosser B.Michel E.Cunha M.S.2021-07-05T06:46:13Z2021-01-22T09:55:40ZCDS support team

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

cds-question@unistra.frasteroseismologygiant-starsMeasuring stellar inclinations is fundamental to understand planetary formation and dynamics as well as physical conditions during star formation. Oscillation spectra of red giant stars exhibit mixed modes that have both a gravity component from the radiative interior and a pressure component from the convective envelope. Gravity-dominated (g-m) mixed modes split by rotation are well separated inside frequency spectra, making possible accurate measurements of stellar inclinations. This work aims at developing an automated and general approach to measure stellar inclinations, that can be applied to any solar-type pulsator for which oscillation modes are identified, and at validating it using red giant branch stars observed by Kepler. The stellar inclination impacts the visibility of oscillation modes with azimuthal orders m=(-1,0,+1). We use the mean height-to-background ratio of dipole mixed modes with different azimuthal orders to measure stellar inclinations. The underlying statistical distribution of inclinations is recovered in an unbiased way using a probability density function for the stellar inclination angle. We derive stellar inclination measurements for 1140 stars on the red giant branch, for which Gehan et al. (2018A&A...616A..24G, Cat. J/A+A/616/A24) have identified the azimuthal order of dipole g-m mixed modes. Raw measured inclinations exhibit strong deviation with respect to isotropy which is expected for random inclinations over the sky. When taking uncertainties into account, the reconstructed distribution of inclinations actually follows the expected isotropic distribution of the rotational axis. This work highlights the biases that affect inclination measurements and provides the way to infer their underlying statistical distribution. When the star is seen either pole-on or equator-on, measurements are challenging and result in a biased distribution. Correcting biases that appear at the low- and high inclination regimes allows us to recover the underlying inclination distribution.2021A&A...645A.124Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/645/A124CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/133 : Kepler Input Catalog (Kepler Mission Team, 2009)J/A+A/540/A143 : Oscillations of red giants observed by Kepler (Mosser+, 2012)J/A+A/588/A87 : Seismic global parameters of 6111 KIC (Vrard+, 2016)J/A+A/616/A24 : Rotation in RGBs from Kepler asteroseismology (Gehan+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/645/A124https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/645/A124http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/645/A124https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/645/A124https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/645/A124http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/645/A124GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/645/A124/incl (Inclination angles and number of visible rotational components)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/645/A124/incl?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/645/A124/incl?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/645/A124/incl?GETtext/xml+votable180.050000true291.3342136.78661440.0055555555555555564/922-923 933-935 944-945 5/3645-3646 3683 3704 3706 3729-3731 3760 3784-3786 3789 3792 6/14567 14573 14575 14578-14579 14588-14589 14591 14730-14731 14744 14746-14747 14750-14751 14792 14794-14795 14822 14828 14830-14831 14914-14915 15044-15045 15057 15059-15062 15148-15150 15153-15155 15160 15172-15174 15178 15200 15232https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/645/A124?format=asciidefaultJ/A+A/645/A124/inclInclination angles and number of visible rotational componentsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKICKIC numbermeta.id;meta.mainintiInclination angledegsrc.orbital.inclination;pos.posAngfloatE_iPositive uncertainty on idegstat.error;stat.maxfloate_iNegative uncertainty on idegstat.errorfloatNcompNumber of visible rotational componentsmeta.numberintRotDisplay rotational splittings from Gehan et al. (2018, Cat. J/A+A/616/A24)meta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main