J/A+A/656/A103ivo://CDS.VizieR/J/A+A/656/A103doi:10.26093/cds/vizier.36560103CDSFritzewski D.J.Barnes S.A.James D.J.Jarvinen S.P.Strassmeier K.G.2023-02-04T18:45:01Z2021-12-08T08:52:52ZCDS support team

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

cds-question@unistra.fropen-star-clusterslate-type-starsline-intensitiesspectroscopyvisible-astronomyThe coeval stars of young open clusters provide insights into the formation of the rotation-activity relationship that elude studies of multi-age field populations. We measure the chromospheric activity of cool stars in the 300 Myr old open cluster NGC 3532 in concert with their rotation periods to study the mass-dependent morphology of activity for this transitional coeval population. Using multi-object spectra of the Ca II infrared triplet region obtained with the AAOmega spectrograph at the 4m Anglo- Australian Telescope, we measure the chromospheric emission ratios R'_IRT_ for 454 FGKM cluster members of NGC3532. The morphology of activity against colour appears to be a near-mirror image of the cluster's rotational behaviour. In particular, we identify a group of 'desaturated transitional rotators' that branches off from the main group of unsaturated FGK slow rotators, and from which it is separated by an 'activity gap'. The few desaturated gap stars are identical to the ones in the rotational gap. Nevertheless, the rotation-activity diagram is completely normal. In fact, the relationship is so tight that it allows us to predict rotation periods for many additional stars. We then precisely determine these periods from our photometric light curves, allowing us to construct an enhanced colour-period diagram that represents 66% of the members in our sample. Our activity measurements show that all fast rotators of near-solar mass (F-G type) have evolved to become slow rotators, demonstrating that the absence of fast rotators in a colour-period diagram is not a detection issue but an astrophysical fact. We also identify a new population of low-activity stars among the early Mdwarfs, enabling us to populate the extended slow rotator sequence in the colour-period diagram. The joint analysis of chromospheric activity and photometric time series data thus enables comprehensive insights into the evolution of the rotation and activity of stars during the transitional phase between the Pleiades and Hyades ages.2021A&A...656A.103Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/656/A103CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/141/115 : BV(RI)c photometry on NGC 3532 (Clem+ 2011)J/A+A/622/A110 : Spectroscopic membership for NGC 3532 (Fritzewski+ 2019)J/A+A/652/A60 : Rotation periods for NGC 3532 (Fritzewski+ 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/656/A103https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/656/A103http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/656/A103https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/656/A103https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/656/A103http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/656/A103GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/656/A103/table1 (Chromospheric emission ratios and rotation periods for 454 member cool star members of the open cluster NGC 3532)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/656/A103/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/656/A103/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/656/A103/table1?GETtext/xml+votable180.050000true167.39084-58.490860.0055555555555555566/37927 37933 37938 37944https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/656/A103?format=asciiOpticaldefaultJ/A+A/656/A103/table1Chromospheric emission ratios and rotation periods for 454 member cool star members of the open cluster NGC 3532recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000) from Clem et al. (2011AJ....141..115C, Cat. J/AJ/141/115)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) from Clem et al. (2011AJ....141..115C, Cat. J/AJ/141/115)degpos.eq.dec;meta.mainCLHWID from Clem et al. (2011AJ....141..115C, Cat. J/AJ/141/115), [CLH2011b] NNNNNN in Simbadmeta.id;meta.mainint(V-Ks)0(V-Ks)_0 colour based on Vmag from Clem et al. (2011AJ....141..115C, Cat. J/AJ/141/115) and 2MASS Ks (1)magphot.color;em.opt;em.IRfloatTeffEffective temperature estimated from (V-Ic)0 (2)Kphys.temperature.effectiveintexcessEWSum of the chromospheric excess equivalent widths measured in the Ca II IRT line cores0.1nmspect.line.eqWidthfloate_excessEWUncertainty of excess_EW0.1nmstat.errorfloatFIRTexcessEW converted to flux in the IRT (10^6^erg/s/cm^2^)1000W.m**-2phot.flux;arith.ratiofloate_FIRTUncertainty of FIRT (10^6^erg/s/cm^2^)1000W.m**-2stat.errordoublelogRIRTLogarithm of normalized excess flux (chromospheric emission ratio)phot.flux;arith.ratiofloate_logRIRTUncertainty of logRIRTstat.errorfloatProt? Photometric rotation period from Fritzewski et al. (2021A&A...652A6..0F, Cat. J/A+A/652/A60)dtime.periodfloatnullablee_Prot? Uncertainty of Protdstat.errorfloatnullableRo? Rossby number (3)stat.paramfloatnullablee_Ro? Uncertainty of Rostat.errorfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlchar