J/A+A/626/A111ivo://CDS.VizieR/J/A+A/626/A111doi:10.26093/cds/vizier.36260111CDSPavlenko Ya.V.Suarez Mascareno A.Zapatero Osorio M.R.Rebolo R.,Lodieu N.Bejar V.J.S.Gonzalez Hernandez J.I.Mohorian M.2019-07-26T09:06:13Z2019-06-20T07:54:27ZCDS support team

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

cds-question@unistra.frspectroscopyWe study temporal variations of the emission lines of H{alpha}, H{epsilon}, H and K CaII, D1 and D2 NaI, He4026, and He5876 in the HARPS spectra of Proxima Centauri across an extended time of 13.2yr, from May 27, 2004 to September 30, 2017. We analyse the common behaviour and differences in the intensities and profiles of different emission lines in flare and quiet modes of Proxima activity. We compare the pseudo-equivalent widths (pEW) and profiles of the emission lines in the HARPS high-resolution (R~115000) spectra observed at the same epochs. Results. All emission lines show variability with a timescale of at least 10 min. The strength of all lines except He4026 correlate with H{alpha}. During strong flares the "red asymmetry" appears in the H{alpha} emission line indicating the infall of hot condensed matter into the chromosphere with velocities greater than 100km/s disturbing chromospheric layers. As a result, the strength of the CaII lines anti-correlates with H{alpha} during strong flares. The HeI lines at 4026 and 5876{AA} appear in the strong flares. The cores of D1 and D2 NaI lines are also seen in emission. During the minimum activity of Proxima Centauri, CaII lines and H{alpha} almost disappear while the blue part of the NaI emission lines is affected by the absorption in the extending and condensing flows. We see different behaviour of emission lines formed in the flare regions and chromosphere. Chromosphere layers of Proxima Cen are likely heated by the flare events; these layers are cooled in the "non-flare" mode. The self-absorption structures in cores of our emission lines vary with time due to the presence of a complicated system of inward and outward matter flows in the absorbing layers.2019A&A...626A.111Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/626/A111CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/328/261 : Spectroscopy of Alpha Cen (Neuforge-Verheecke+ 1997)J/A+A/406/L23 : Solar-like oscillations in alpha Cen B (Carrier+, 2003)J/A+A/415/331 : HST/STIS spectra of alpha Cen A (Pagano+, 2004)J/A+A/459/669 : JHKs photometry around {alpha} Cen (Kervella+, 2006)J/A+A/464/373 : VRIZJHK photometry around Alpha Cen (Kervella+, 2007)J/A+A/534/A133 : Proxima Cen chromospheric emission lines (Fuhrmeister+, 2011)J/A+A/597/A137 : HD 123999 and Alpha Cen A and B OIFITS files (Kervella+, 2017)J/A+A/615/A172 : alpha Cen A and B chemical composition (Morel, 2018)J/AJ/155/24 : alpha Cen radial velocity & planet detectability (Zhao+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/626/A111https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/626/A111http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/626/A111https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/626/A111https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/626/A111http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/626/A111GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/626/A111/tablea1Pseudoequivalent widths (pEW) of some emission lines measured in HARPS spectra observed on dates BJD=2453152-2458027recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBaricentric Julian date (BJD-2450000)dtime.epochdoublepEWHaH{alpha} pseudo-equivalent width0.1nmspect.line.width;em.line.HalphafloatpEWCaIIKCaII(K) pseudo-equivalent width0.1nmspect.line.widthfloatpEWCaIIHCaII(H) pseudo-equivalent width0.1nmspect.line.widthfloatpEWHeI5876He5876{AA} pseudo-equivalent width0.1nmspect.line.widthfloatpEWHeI4026He4026{AA} pseudo-equivalent width0.1nmspect.line.widthfloatpEWHeH{epsilon} pseudo-equivalent width0.1nmspect.line.widthfloatpEWNaID2NaI(D_2_) pseudo-equivalent width0.1nmspect.line.widthfloatpEWNaID1NaI(D_1_) pseudo-equivalent width0.1nmspect.line.widthfloat