J/MNRAS/527/2940ivo://CDS.VizieR/J/MNRAS/527/2940doi:10.26093/cds/vizier.75272940CDSCretignier M.Pietrow A.G.MAigrain S.2024-11-06T20:35:02Z2024-05-02T12:59:16ZCDS support team

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

cds-question@unistra.frthe-sunspectroscopyThe detection of Earth-like planets with the radial-velocity method is currently limited by the presence of stellar activity signatures. On rotational timescales, spots and plages (or faculae) are known to introduce different RV signals, but their corrections require better activity proxies. The best-known chromospheric activity proxies in the visible are the CaII H & K lines, but the physical quantities measured by their profiles need to be clarified. We first investigate resolved images of the Sun in order to better understand the spectrum of plages, spots, and the network using the Meudon spectroheliogram. We show that distinct line profiles are produced by plages, spots, and by the network component and we also derived the center-to-limb variations of the three profiles. Some care is required to disentangle their contributions due to their similarities. By combining disk-integrated spectra from the ISS high-resolution spectrograph with SDO direct images of the Sun, we managed to extract a high-resolution emission spectrum of the different components, which tend to confirm the spectra extracted from the Meudon spectroheliogram datacubes. Similar results were obtained with the HARPS-N Sun-as-a-star spectra. We concluded using a three-component model that the temporal variation of the popular Sindex contains, on average for the 24th solar cycle: 70+/-12% of plage, 26+/-12% of network and 4+/-4% of spots. This preliminary investigation suggests that a detailed study of the CaII H & K profiles may provide rich information about the filling factor and distribution of different types of active regions.2024MNRAS.527.2940Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/527/2940CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/527/2940https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/527/2940http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/527/2940https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/527/2940https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/527/2940http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/527/2940GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/MNRAS/527/2940/quietCLV profiles for quiet SunrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndexIndex of the tablemeta.idintlambdaWavelengthnmem.wldoubleFlux0.078Flux at mu=0.078%phot.fluxdoubleFlux0.156Flux at mu=0.156%phot.fluxdoubleFlux0.253Flux at mu=0.253%phot.fluxdoubleFlux0.353Flux at mu=0.353%phot.fluxdoubleFlux0.452Flux at mu=0.452%phot.fluxdoubleFlux0.552Flux at mu=0.552%phot.fluxdoubleFlux0.646Flux at mu=0.646%phot.fluxdoubleFlux0.751Flux at mu=0.751%phot.fluxdoubleFlux0.846Flux at mu=0.846%phot.fluxdoubleFlux0.946Flux at mu=0.946%phot.fluxdoubleJ/MNRAS/527/2940/spotCLV profiles for spot SunrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndexIndex of the tablemeta.idintlambdaWavelengthnmem.wldoubleFlux0.353Flux ratio (AR/Quiet) at mu=0.353phot.fluxdoubleFlux0.459Flux ratio (AR/Quiet) at mu=0.459phot.fluxdoubleFlux0.551Flux ratio (AR/Quiet) at mu=0.551phot.fluxdoubleFlux0.650Flux ratio (AR/Quiet) at mu=0.650phot.fluxdoubleFlux0.758Flux ratio (AR/Quiet) at mu=0.758phot.fluxdoubleFlux0.860Flux ratio (AR/Quiet) at mu=0.860phot.fluxdoubleFlux0.941Flux ratio (AR/Quiet) at mu=0.941phot.fluxdoubleJ/MNRAS/527/2940/plageCLV profiles for plage SunrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndexIndex of the tablemeta.idintlambdaWavelengthnmem.wldoubleFlux0.352Flux ratio (AR/Quiet) at mu=0.352phot.fluxdoubleFlux0.454Flux ratio (AR/Quiet) at mu=0.454phot.fluxdoubleFlux0.553Flux ratio (AR/Quiet) at mu=0.553phot.fluxdoubleFlux0.651Flux ratio (AR/Quiet) at mu=0.651phot.fluxdoubleFlux0.753Flux ratio (AR/Quiet) at mu=0.753phot.fluxdoubleFlux0.856Flux ratio (AR/Quiet) at mu=0.856phot.fluxdoubleFlux0.940Flux ratio (AR/Quiet) at mu=0.940phot.fluxdouble