J/A+A/607/A124ivo://CDS.VizieR/J/A+A/607/A124doi:10.26093/cds/vizier.36070124CDSMeunier N.Mignon L.Lagrange A.-M.2017-12-13T18:40:37Z2017-11-24T07:18:47ZCDS support team

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

cds-question@unistra.frdwarf-starsmagnetic-fieldsThe inhibition of small-scale convection in the Sun dominates the long-term radial velocity (RV) variability: it therefore has a critical effect on light exoplanet detectability using RV techniques. We here extend our previous analysis of stellar convective blueshift and its dependence on magnetic activity to a larger sample of stars in order to extend the Teff range, to study the impact of other stellar properties, and finally to improve the comparison between observed RV jitter and expected RV variations. Methods. We estimate a differential velocity shift for Fe and Ti lines of different depths and derive an absolute convective blueshift using the Sun as a reference for a sample of 360 F7-K4 stars with different properties (age, Teff, metallicity). We confirm the strong variation in convective blueshift with Teff and its dependence on (as shown in the line list in Paper I) activity level. Although we do not observe a significant effect of age or cyclic activity, stars with a higher metallicity tend to have a lower convective blueshift, with a larger effect than expected from numerical simulations. Finally, we estimate that for 71% of the stars in our sample the RV and LogR'_HK_ variations are compatible with the effect of activity on convection, as observed in the solar case, while for the other stars, other sources (such as binarity or companions) must be invoked to explain the large RV variations. We also confirm a relationship between LogR'_HK_ and metallicity, which may affect discussions of the possible relationship between metallicity and exoplanets, as RV surveys are biased toward low LogR'_HK_ and possibly toward high-metallicity stars. We conclude that activity and metallicity strongly affect the small-scale convection levels in stars in the F7-K4 range, with a lower amplitude for the lower mass stars and a larger amplitude for low-metallicity stars.2017A&A...607A.124Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/607/A124CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/597/A52 : K and G dwarfs stellar granulation variability (Meunier+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/607/A124https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/607/A124http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/607/A124https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/607/A124https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/607/A124http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/607/A124GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/607/A124/tablea1 (List of stars studied in the paper)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/607/A124/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/607/A124/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/607/A124/tablea1?GETtext/xml+votable180.050000true276.9561814-29.81686310.0055555555555555566/137 222 4128 4313 4665 8244 8286 8614 8792 12890 16502 16518 16639 16652 16883 16986 17171 17177 17218 17249 17266 17301 17314 17341 17419 17425 17435 17529 17540-17541 17572 17607 17641 17714 17721 17730 17768 17804 17944 18005 18139 18373 18548 18614-18615 18623 18637 18641 18711 18785 18792 19003 19072 19108 19491 20557 20593 20621 20640 20746 20873 21066 21080 21114 21117 21121 21177 21386 21400 21412 21477 21484 21516 21691 21696 21779 21906 22036 22159 22608 22613 22619 22708 22746 22818 23096 23123 23177 23429 23583 23661 23780 23873 24729 24769 24831 24924 25078 25102 25225 25567 25584 25622 25854 25880 25889 25906 25939 26160 26183 26242 26496 26652 26676 26768 26828 26888 26906 26924 27018 27254 28719 28763 28874 28887 28961 29289 29422 29675 29721 29833 29838 29842 29900 30310 30343 30848 30878 30943 30951 30965 31029 31101 31130 31433 32787 32848 32986 33063 33082 33091 33210 33219 33252 33357 33418 33442 33456 33510 33552 33630 33662 33705 33813 33879 33945 34336 34442 34446 34481 34530 34673 34817 34864 34947 34983 35121 35230 35440 35468 35691 35733 35784 35831 35896 35928 35954 35968-35969 36019 36288 36453 36590 36635 36664 36697 36723 36813 37074 37419 37422 37595 37660 37807-37808 37831 37954-37955 38099 38219 38229 38238 38279 38311 38339 38414 38434 38443 38545 38562 38605 38698 38738 38742 38765 38788 38807 38857 38932 38955 38998 39034 39219 39257 39282-39283 39364 39377 39422 39461 39576 39693 39767 39854 39915 40007 40078 40105 40317 40442 40453 40686-40687 40692 40722 40802 40921 40932 40938 41094 41143 41463 41590 41607 41611-41612 41723-41724 41752 41861 41912 41935 41941 41954 41969 42022 42146 42157 42171 42228 42326 42448 42460 42814 42887 42918 43105 43228 43258 43290 43345 43544 43649 43724 43911 43977 43989 44131 44150 44262 44359 44557 44792 45121 45182 45228 45265 45334 45485 45502 45511 45589 45627 45641 45668 45865 45902 46056 46076 46080 46135 46172 46193 46234 46287 46306 46355 46640 46664 46681 46734 46800 46874 46923 46967 46997 47020 47045 47137 47364 47590 47629 47740 47858 48362 48519 48530 48545 48607 48652 48664 48705 48821 48846 48943 49060 49114 49128https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/607/A124?format=asciidefaultJ/A+A/607/A124/tablea1List of stars studied in the paperSimbadNameSimbad column added by the CDSmeta.idcharTeffTeffKphys.temperature.effectiveintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharr_TeffReference for Teff (1)meta.ref;pos.frameintSpTypeSpectral type from the CDSsrc.spTypecharB-VB-V from the CDSphot.color;em.opt.B;em.opt.VfloatNspNumber of spectra used in the analysismeta.numberintTSSSlope of the radial velocity versus line intensity in m/s/(F/Fc) unit (2)stat.fit.paramfloate_TSS1-sigma uncertainty on TSS in m/s/(F/Fc)stat.errorfloatlogR'HKAveraged Mount Wilson logR'_HK_ indexphot.flux;arith.ratiofloate_logR'HK1-sigma uncertainty on logR'HKstat.errorfloatConvBLConvective blueshift (3)m/sspect.dopplerVelocfloatAgeAgeGyrtime.agefloatr_Age? Reference for the age (1)meta.ref;pos.frameintnullablevsini? Rotational velocitykm/sphys.veloc.rotatfloatnullabler_vsini? Reference for the vsini (1)meta.refintnullableSourceSurvey including the star (1)meta.bibchar_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