J/A+A/692/A245ivo://CDS.VizieR/J/A+A/692/A245doi:10.26093/cds/vizier.36920245CDSSerebriakova N.Tkachenko A.Aerts C.2025-02-26T20:02:40Z2024-12-17T10:58:23ZCDS support team

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

cds-question@unistra.frmilky-way-galaxymagellanic-cloudsearly-type-starseffective-temperatureSpectral lines of hot massive stars are known to exhibit large excess broadening in addition to rotational broadening. This excess broadening is often attributed to macroturbulence, whose physical origin is a matter of active debate in the stellar astrophysics community. We aim to shed light on the physical origin of macroturbulent line broadening by looking into the statistical properties of a large sample of O- and B-type stars both in the Galaxy and the Large Magellanic Cloud (LMC). We deliver newly measured macroturbulent velocities for 86 stars from the Galaxy in a consistent manner with 126 stars from the LMC. We composed a total sample of 594 stars with measured macroturbulent velocities by complementing our sample with archival data for the Galactic O- and B-type stars in order to gain better coverage of the parameter space. Furthermore, we computed an extensive grid of MESA models to compare, in a statistical manner, the predicted interior properties of stars (such as convection and wave propagation) with the inference of macroturbulent velocities from high-resolution spectroscopic observations. We find evidence for subsurface convective zones that formed in the iron opacity bump (FeCZ) being connected to observed macroturbulent velocities in hot massive stars. Additionally, we find the presence of two principally different regimes where, depending on the initial stellar mass, different mechanisms may be responsible for the observed excess line broadening. Stars with initial masses above 30M_{sun}_ exhibit macroturbulent velocities that are in line with FeCZ properties, as indicated by the trends in both observations and models. For stars below 12M_{sun}_, alternative mechanisms are needed to explain macroturbulent broadening, such as internal gravity waves (IGWs). Finally, in the intermediate range between 12 and 30M_{sun}_, IGWs tunnelling through subsurface convective layers combined with the presence of FeCZ-driven convection suggests that both processes could contribute to the observed macroturbulent velocities. This intermediate regime presents a region where the interplay between these two (or more) mechanisms remains to be fully understood.2024A&A...692A.245Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/692/A245CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/665/A36 : FEROS spectroscopy of B-type stars (Gebruers+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/692/A245https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/692/A245http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/692/A245https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/692/A245https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/692/A245http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/692/A245GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/692/A245/table (*Relevant parameters of the sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/692/A245/table?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/692/A245/table?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/692/A245/table?GETtext/xml+votable180.050000true114.0802542-69.05654080.0055555555555555565/8269 8275 8280 6/16617 32852 32877 32935 33030 33035 33049 33053 33055 33073-33075 33091-33092 33094-33098 33104-33106 33108 33112-33113 33115 33117 33124 33126-33128 33130 33137 33156 33190 33814 33832 33842 34873 37033 37101 37410-37411 37421-37422 37428-37429 37440 37443 37450 37452 37454 37481 37485 37487 37496 37509 37513 37516-37517 37521 37525 37527 37534 37541 37543 37552 37571-37572 37575 37578 37584 37587 37592-37593 37604 38912 38915 38917 38926 38940 38952 38957 38961 38964 38967-38968 38976 39044 39053 39057 39065 45343 46335 46619 46986 47005 48146 48455https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/692/A245?format=asciidefaultJ/A+A/692/A245/table*Relevant parameters of the sampleVmacro? Macroturbulent velocitykm/sphys.veloc.microTurbfloatnullablee_Vmacro? Error in Vmacrokm/sstat.errorfloatnullableLsLog10 Spectroscopic luminosity Teff^4/glog(K**4.g**-1)phys.luminosityfloate_LsError in Lslog(K**4.g**-1)stat.errorfloat_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.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject namemeta.id;meta.maincharTeffEffective temperature (rounded) (1)Kphys.temperature.effectiveinte_TeffError in effective temperature (1)Kstat.error;phys.temperature.effectiveintloggLog10 Surface gravity (1)log(cm.s**-2)phys.gravityfloate_loggError in logg (1)log(cm.s**-2)stat.errorfloatVsini-spProjected rotational velocity (1) (2)km/sphys.veloc.rotatfloate_Vsini-spError in Vsini-sp (1)km/sstat.errorfloatVsini-fourier? Projected rotational velocity (Fourier) (3)km/sphys.veloc.rotatfloatnullablee_Vsini-fourier? Error in Vsini-fourierkm/sstat.errorfloatnullableSimbadNameSimbad column added by the CDSmeta.idcharnullableSampSample (4)src.samplechar