J/ApJ/904/13ivo://CDS.VizieR/J/ApJ/904/13doi:10.26093/cds/vizier.19040013CDSGraczyk D.Pietrzynski G.Thompson I.B.Gieren W.Zgirski B.,Villanova S.Gorski M.Wielgorski P.Karczmarek P.Narloch W.,Pilecki B.Taormina M.Smolec R.Suchomska K.Gallenne A.Nardetto N.,Storm J.Kudritzki R.-P.Kaluszynski M.Pych W.2022-09-30T23:05:10Z2022-03-16T08:43:37ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsmultiple-starsgiant-starsvisible-astronomyspectroscopyradial-velocityWe present a new study of late-type eclipsing binary stars in the Small Magellanic Cloud (SMC) undertaken with the aim of improving the distance determination to this important galaxy. A sample of 10 new detached, double-lined eclipsing binaries identified from the OGLE variable star catalogs and consisting of F- and G-type giant components has been analyzed. The absolute physical parameters of the individual components have been measured with a typical accuracy of better than 3%. All but one of the systems consist of young and intermediate population stars with masses in the range of 1.4 to 3.8M{sun}. This new sample has been combined with five SMC eclipsing binaries previously published by our team. Distances to the binary systems were calculated using a surface brightness-color calibration. The targets form an elongated structure, highly inclined to the plane of the sky. The distance difference between the nearest and most-distant system amounts to 10kpc with the line-of-sight depth reaching 7kpc. We find tentative evidence of the existence of a spherical stellar substructure (core) in the SMC coinciding with its stellar center, containing about 40% of the young and intermediate age stars in the galaxy. The radial extension of this substructure is ~1.5kpc. We derive a distance to the SMC center of DSMC=62.44{+/-}0.47(stat.){+/-}0.81(syst.)kpc corresponding to a distance modulus (m-M)SMC=18.977{+/-}0.016{+/-}0.028mag, representing an accuracy of better than 2%.2020ApJ...904...13Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/904/13CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/288 : IRSF Magellanic Clouds Point Source Catalog (Kato+ 2007)II/351 : VISTA Magellanic Survey (VMC) catalog (Cioni+, 2011)VI/120 : High-resolution synthetic stellar library (Coelho+, 2005)J/AJ/106/2096 : Limb-darkening coefficients in binaries (Van Hamme 1993)J/ApJ/469/355 : Teff, B-V and BC relation (Flower, 1996)J/A+A/339/858 : Calibration of stellar parameters (Di Benedetto 1998)J/AJ/119/1448 : Improved properties for cool stars (Houdashelt+, 2000)J/AcA/54/1 : OGLE II SMC eclipsing binaries (Wyrzykowski+, 2004)J/A+A/450/735 : Effective temperatures and radii of stars (Masana+, 2006)J/AJ/134/1963 : MACHO r,b light curves MC eclipsing binaries (Faccioli+, 2007)J/ApJ/663/320 : IR-through-UV extinction curve (Fitzpatrick+, 2007)J/A+A/475/1003 : Stellar parameters of G and K giant stars (Hekker+, 2007)J/A+A/490/625 : Abundances of NGC 6121 red giants (Marino+, 2008)J/AJ/135/209 : Rotational & radial veloc 761 HIP giants (Massarotti+, 2008)J/A+A/497/497 : Physical parameters from JHK flux (Gonzalez-Hernandez+, 2009)J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)J/ApJS/193/1 : UBVRIJHK color-temperature calibration (Worthey+, 2011)J/AcA/63/323 : OGLE-III SMC eclipsing binary stars (Pawlak+, 2013)J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)J/A+A/557/A119 : Eclipsing binary system LL Aquarii (Southworth, 2013)J/MNRAS/449/639 : VMC survey. XIV. SFR in SMC (Rubele+, 2015)J/AcA/66/405 : Galactic bulge eclipsing & ellipsoidal bin (Soszynski+, 2016)J/ApJS/224/21 : The VMC survey. XIX. Classical Cepheids in SMC (Ripepi+, 2016)J/ApJ/816/49 : Spitzer/IRAC observations of SMC Cepheids (Scowcroft+, 2016)J/MNRAS/472/808 : YJKs light curves of SMC Classical Cepheids (Ripepi+, 2017)J/MNRAS/478/3138 : Luminous cool supergiants Magellanic Clouds (Davies+, 2018)J/A+A/620/A99 : SMC Cepheids K-band and RV curves (Gieren+, 2018)J/ApJ/860/1 : Radial velocity measurements of 20 EBs in LMC (Graczyk+, 2018)J/ApJ/860/1 : Radial velocity measurements of 20 EBs in LMC (Graczyk+, 2018)J/MNRAS/473/3131 : VMC survey. XXVI. SMC RR Lyrae stars (Muraveva+, 2018)J/ApJ/887/267 : OB stars embedded in the HI gas of SMC (Murray+, 2019)J/ApJ/876/85 : HST observations for LMC Cepheids (Riess+, 2019)J/A+A/640/A2 : Dwarfs & giants surface brightness-colour relat. (Salsi+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/904/13https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/904/13http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/904/13https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/904/13https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/904/13http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/904/13GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/904/13/table1 (Target stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/904/13/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/904/13/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/904/13/table1?GETtext/xml+votable180.050000true5.7313333-73.88791670.0055555555555555566/33294-33295 33313 33316-33317 33319https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/904/13?format=asciiOpticaldefaultJ/ApJ/904/13/table1Target starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintOGLEOGLE identifier (SMC-ECL-NNNN)meta.id;meta.mainintprimaryMACHOMACHO identifiermeta.id.crosscharRAJ2000[0] Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000[71/73] Degree of declination (J2000)pos.eq.dec;meta.mainVmag[15.5/18.2] V-band magnitudemagphot.mag;em.opt.VfloatImag[14.8/17.2] I-band magnitudemagphot.mag;em.opt.IfloatJmag[14.2/16.6] J-band magnitudemagphot.mag;em.IR.JfloatKmag[13.8/16] K-band magnitudemagphot.mag;em.IR.KfloatPer[73.7/317] Orbital perioddtime.perioddoubleHJD[2452023/2456683] Epoch of th primary minimumdtime.epochdoublenRVelNumber of radial velocities observed (table2)meta.numberintnullableRVelInteractive Plotmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/904/13/table2The radial velocity measurementsHJD[4784/8842] Heliocentric Julian date JD-2450000dtime.epochdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintOGLEOGLE identifier (SMC-ECL-NNNN)meta.id;meta.mainintRVel1[68.2/216] Radial Velocity of the first componentm/sphys.veloc;pos.heliocentricfloate_RVel1[0.1/1.8] The 1-sigma uncertainty in RVel1m/sstat.errorfloatRVel2[68.1/224] Radial Velocity of the second componentm/sphys.veloc;pos.heliocentricfloate_RVel2[0.08/0.6] The 1-sigma uncertainty in RVel2m/sstat.errorfloatInstrSpectrograph used; MIKE, HARP ans UVESmeta.id;instrchar