J/AJ/162/253ivo://CDS.VizieR/J/AJ/162/253doi:10.26093/cds/vizier.51620253CDSMartinez-vazquez C.E.Cerny W.Vivas A.K.Drlica-wagner A.Pace A.B.,Simon J.D.Munoz R.R.Walker A.R.Allam S.Tucker D.L.Adamow M.,Carlin J.L.Choi Y.Ferguson P.S.Ji A.P.Kuropatkin N.Li T.S.,Martinez-delgado D.Mau S.Mutlu-pakdil B.Nidever D.L.Riley A.H.,Sakowska J.D.Sand D.J.Stringfellow G.S.(the Delve Collaboration)2022-09-30T23:13:14Z2022-03-07T07:03:23ZCDS support team

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

cds-question@unistra.frvariable-starsmilky-way-galaxyinfrared-photometryvisible-astronomybroad-band-photometryWe report the detection of three RR Lyrae (RRL) stars (two RRc and one RRab) in the ultra-faint dwarf (UFD) galaxy CentaurusI (CenI) and two Milky Way (MW) {delta}Scuti/SX Phoenicis stars based on multi-epoch giz DECam observations. The two RRc stars are located within two times the half-light radius (r_h_) of CenI, while the RRab star (CenI-V3) is at ~6r_h_. The presence of three distant RRL stars clustered this tightly in space represents a 4.7{sigma} excess relative to the smooth distribution of RRL in the Galactic halo. Using the newly detected RRL stars, we obtain a distance modulus to CenI of {mu}_0_=20.354{+/-}0.002mag ({sigma}=0.03mag), a heliocentric distance of D{sun}=117.7{+/-}0.1kpc ({sigma}=1.6kpc), with systematic errors of 0.07mag and 4kpc. The location of the CenI RRL stars in the Bailey diagram is in agreement with other UFD galaxies (mainly OosterhoffII). Finally, we study the relative rate of RRc+RRd (RRcd) stars (f_cd_) in UFD and classical dwarf galaxies. The full sample of MW dwarf galaxies gives a mean of f_cd_=0.28. While several UFD galaxies, such as CenI, present higher RRcd ratios, if we combine the RRL populations of all UFD galaxies, the RRcd ratio is similar to the one obtained for the classical dwarfs (f_cd_~0.3). Therefore, there is no evidence for a different fraction of RRcd stars in UFD and classical dwarf galaxies.2021AJ....162..253Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/162/253CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/337 : Gaia DR1 (Gaia Collaboration, 2016)II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)I/345 : Gaia DR2 (Gaia Collaboration, 2018)II/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)II/371 : The Dark Energy Survey (DES): Data Release 2 (Abott+, 2021)J/ApJ/763/32 : Galactic halo RRab stars from CSS (Drake+, 2013)J/ApJ/781/22 : Region I of La Silla QUEST RR Lyrae star survey (Zinn+, 2014)J/PASP/126/616 : Variable stars in Leo I dSph (Stetson+, 2014)J/ApJ/808/11 : RR Lyrae stars in M4. II. Spitzer/IRAC phot. (Neeley+, 2015)J/MNRAS/462/4349 : Variable stars in Sculptor dSph (Martinez-Vazquez+, 2016)J/ApJ/850/137 : ISLAndS project. III. Variable stars (Martinez-Vazquez+, 2017)J/ApJ/855/43 : Distant RR Lyrae stars discovered with HiTS (Medina+, 2018)J/ApJ/867/105 : ATLAS all-sky stellar ref. cat, ATLAS-REFCAT2 (Tonry+, 2018)J/AJ/157/35 : Population of pulsating variable stars Sextans (Vivas+, 2019)J/ApJ/870/83 : Abundances in ultra-faint dwarf gal. GruI & TriII (Ji+, 2019)J/ApJ/875/77 : Proper motions of MW satellites with Gaia & DES (Pace+, 2019)J/AJ/161/120 : gri photometry for 73 stars in NGC419 (Martinez-Vazquez+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/162/253https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/162/253http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/162/253https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/162/253https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/162/253http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/162/253GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/162/253/table2 (Coordinates, pulsation properties, and average photometry of variable stars in Cen I)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/162/253/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/162/253/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/162/253/table2?GETtext/xml+votable180.050000true189.57032306-40.939878890.0055555555555555566/43671https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/162/253?format=asciiOpticalInfrareddefaultJ/AJ/162/253/table2Coordinates, pulsation properties, and average photometry of variable stars in Cen IIDStellar identificationmeta.id;meta.maincharprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[189/190] Degree of right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-42/-40] Degree of declination (J2000)degpos.eq.dec;meta.mainRad[2.38/16.2] Elliptical radius measured from each star to the center of Cen Iarcminphys.angSizefloatPer[0.04/0.74] Perioddtime.perioddoublegmag[20.3/21.3] g-band magnitudemagphot.mag;em.optfloatimag[20.1/21] i-band magnitudemagphot.mag;em.opt.Ifloatzmag[20.1/20.9] z-band magnitudemagphot.mag;em.IRfloatl_Ampg[>] Limit flag on Ampgmeta.code.errorcharAmpg[0.27/0.72] Amplitude in g-bandmagsrc.var.amplitudefloatl_Ampi[>] Limit flag on Ampimeta.code.errorcharAmpi[0.19/0.37] Amplitude in i-bandmagsrc.var.amplitudefloatl_Ampz[>] Limit flag in Ampzmeta.code.errorcharAmpz[0.13/0.33] Amplitude in z-bandmagsrc.var.amplitudefloatTypeType of starsrc.classcharf_Typea = Milky Way field stars (2 occurrences)meta.codecharNobsNumber of observationmeta.numberintnullableLCInteractive Plotmeta.ref.urlcharJ/AJ/162/253/table1Photometry of the variable stars found in the field of Cen IIDVariable identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDg[56373/58926]? Modified Julian Date of g band observation of mid-exposuredtime.epochdoublenullablegmag[19.9/21.6]? Apparent g band magnitudemagphot.mag;em.optfloatnullablee_gmag[0.005/0.06]? Uncertainty in gmagmagstat.error;phot.magfloatnullableMJDi[56357/58926]? Modified Julian Date of i band observation of mid-exposuredtime.epochdoublenullableimag[19.8/21.1]? Apparent i band magnitudemagphot.mag;em.opt.Ifloatnullablee_imag[0.007/0.06]? Uncertainty in imagmagstat.error;phot.magfloatnullableMJDz[56314/58926]? Modified Julian Date of z band observation of mid-exposuredtime.epochdoublenullablezmag[19.8/21.1]? Apparent z band magnitudemagphot.mag;em.IRfloatnullablee_zmag[0.008/0.07]? Uncertainty in zmagmagstat.error;phot.magfloatnullable