J/AJ/165/70ivo://CDS.VizieR/J/AJ/165/70doi:10.26093/cds/vizier.51650070CDSCrandall S.Smith G.H.2023-09-27T13:35:28Z2023-06-14T10:03:27ZCDS support team

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

cds-question@unistra.frgiant-starsultraviolet-photometryvisible-astronomyx-ray-sourcesThe main goal of this paper is to use ultraviolet photometry from the Galaxy Evolution Explorer (GALEX) satellite to study chromospheric activity among red giant and core-helium-burning (CHeB) stars. Correlations are sought between several chromospheric and coronal activity indicators for giants that were detected in soft X-rays by the ROentgen SATellite. There is an evident correlation between log(L_X_L_bol_) and log(F_MgII_/F_bol_), where LX is the X-ray luminosity and FMgII is the flux from MgIIh and k emission lines, although there is substantial scatter. Using GALEX far-ultraviolet (FUV) magnitudes, the relationship between an FUV-excess parameter (a proxy for chromospheric and transition-region emission lines) and X-ray luminosity is documented. Correlations found herein are not strong, and may be linked to binarity. There is a varied range of FUV emission among CHeB stars, indicating that giants in this phase may be exhibiting differences or cycles in outer atmospheric activity. Additionally, efforts were made to constrain a relationship between excess FUV and near-ultraviolet emission and the projected surface rotation velocity, vsini, of giants. No clear relationship was found. Obscurities in this relationship may result from a spread in sini inclinations, and/or too few stars with vsini>7km/s.2023AJ....165...70Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/165/70CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/simbad : Simbad objects catalogue (M.Wenger 2000)II/84 : 13-color photometry of 1380 bright stars (Johnson+ 1975)II/97 : ANS UV Catalogue of Point Sources (Wesselius+ 1982)II/122 : UBV Photoelectric Catalog; data 1953-1985 (Mermilliod 1987)III/150 : Perkins Revised MK Types for the Cooler Stars (Keenan+ 1989)I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/ApJ/348/253 : Late type giants and supergiants in X-Ray (Maggio+, 1990)J/A+AS/127/251 : Giants and supergiants ROSAT data (Huensch+ 1998)J/A+A/397/147 : Activity-rotation relationship in stars (Pizzolato+ 2003)J/AJ/135/209 : Rot. & radial velocities 761 HIP giants (Massarotti+, 2008)J/MNRAS/414/418 : Chromospheric Mg II h+k flux of evolved stars (Perez+, 2011)J/MNRAS/422/2024 : X-ray-age relation & exoplanet evaporation (Jackson+, 2012)J/A+A/616/A10 : 46 open clusters GaiaDR2 HR diag. (Gaia Collaboration, 2018)J/ApJ/872/95 : GALEX & Gaia data APOGEE red clump stars (Mohammed+, 2019)J/AJ/160/217 : 342 FGK-dwarfs ages using GALEX FUV mag (Crandall+, 2020)J/AJ/160/12 : J, Ks, NUV emission of 133 red giant stars (Dixon+, 2020)J/ApJ/902/114 : Stellar Xray activity I. Chandra, Gaia & GALEX (Wang+, 2020)J/A+A/649/A3 : Gaia EDR3 photometric passbands (Riello+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/165/70https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/165/70http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/165/70https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/165/70https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/165/70http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/165/70GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/165/70/table2 (GALEX data for a ROSAT giant star sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/165/70/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/165/70/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/165/70/table2?GETtext/xml+votable180.050000true4.14184118.24015720.0055555555555555566/31 128 725 959 1495 1734 2025 2062 2076 2170 2371 2490 3390 3423 3560 3799 3878 3969 4123 4167 4559 4794 4822 4969 5019 5041 5253 5278 5490 5581 5676 6183 6267 6298 6693 7122 7402 7435 7610 7747 8333 8543 8626 8689 9213 9247 9425 9510 9553 9610 9751 9967 10023 10055 10184 10263 10407 10451 10632 10886 11519 11547 12009 12021 12208 12211 12402 12482 12516 13697 14826 15012 15021 15147 15153 15217 15226 15730 15865 15998 16013 16496 16704 16872 17266 17458 17470 17811 17852 17989 18304 18730 18783 18888 19414 19531 19718 19921 19930 20102 20178 20205 20460 20893 21286 21776 21926 22982 24296 24877 25071 25182 25211 25278 25311 25321 26448 26552 26950 27520 27710 27791 28634 29608 29800 30029 30037 30376 31039 31113 31581 32271 32803 32831 32834 32843 32875 33027 33471 33655 33774 33874 34075 34602 35080 35116 35284 35351 35396 36206 36433 36806 36973 37126 37289 37548 38349 38605 38630 38806 38860 39068 39093 39953 40324 40690 40757 40826 41039 42005 43602 44015 44268 44478 45249 45530 45538 46299 46318 46327 46430 46469 46725 47078 47237 47584 48183 48188 48319 48455 48505 485721.9867573869263685e-19 1.4134638842407062e-18https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/165/70?format=asciiX-rayUVOpticaldefaultJ/AJ/165/70/table2GALEX data for a ROSAT giant star sampleSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource identifiermeta.id;meta.maincharFUVmag[11.4/21.4] GALEX GR6/7 catalog FUV magnitudemagphot.mag;em.UVfloatQ[-9.04/8.22] FUV-excess parametermagphot.color;em.UVfloate_FUVmag[0/0.4] Uncertainty in FUVmagmagstat.error;phot.magfloatGmag[2.22/7.06] Gaia EDR3 G band magnitudemagphot.mag;em.opt.Vfloate_Gmag[0/0.03] Uncertainty in Gmagmagstat.error;phot.magfloatBPmag[3.22/7.51] Gaia EDR3 Blue passband magnitudemagphot.mag;em.opt.Bfloate_BPmag[0/0.5] Uncertainty in Bpmagmagstat.error;phot.magfloatLX/Lbol[-7.62/-3.9] log ROSAT X-ray to bolometric luminositiesphys.luminosity;em.X-rayfloat_RAPosition from SIMBAD (right ascension part)degpos.eq.ra;meta.mainnullable_DEPosition from SIMBAD (declination part)degpos.eq.dec;meta.mainnullable