J/ApJ/906/125ivo://CDS.VizieR/J/ApJ/906/125doi:10.26093/cds/vizier.19060125CDSJang In S.Hoyt T.J.Beaton R.L.Freedman W.L.Madore B.F.Lee M.G.,Neeley J.R.Monson A.J.Rich J.A.Seibert M.2022-09-05T14:03:06Z2022-06-02T07:42:57ZCDS support team

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

cds-question@unistra.frgiant-starshst-photometryvisible-astronomyIn the nearby galaxy NGC4258, the well-modeled orbital motion of H_2_O masers about its supermassive black hole provides the means to measure a precise geometric distance. As a result, NGC4258 is one of a few "geometric anchors" available to calibrate the true luminosities of stellar distance indicators such as the Tip of the Red Giant Branch (TRGB) or the Cepheid Leavitt law. In this paper, we present a detailed study of the apparent magnitude of the TRGB within NGC4258, using publicly available HST observations optimally situated in the unreddened stellar halo along the minor axis, spanning distances ranging from 8 to 22kpc in projected galactocentric radius, or 6' (13kpc) to 30' (66kpc) in distance along the semimajor axis. We undertake a systematic evaluation of the uncertainties associated with measuring the TRGB in this galaxy, based on an analysis of 54arcmin^2^ of HST/ACS imaging. After quantifying these uncertainties, we measure the TRGB in NGC4258 to be F814W0=25.347{+/-}0.014(stat){+/-}0.042(sys)mag. Combined with a recent 1.5% megamaser distance to NGC4258, we determine the absolute luminosity of the TRGB to be M_F814W_^TRGB^-4.050{+/-}0.028(stat){+/-}0.048(sys)mag. This new calibration agrees to better than 1% with an independent calibration presented in Freedman et al. that was based on detached eclipsing binaries (DEBs) located in the LMC.2021ApJ...906..125Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/906/125CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/652/1133 : BVI photometry of NGC 4258 Cepheids (Macri+, 2006)J/AJ/138/332 : LEDA CMD/tip of the red giant branch (Jacobs+, 2009)J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)J/ApJ/845/146 : The Carnegie-Chicago Hubble Program. II. IC 1613 (Hatt+, 2017)J/ApJS/235/23 : LEGUS galaxies1 observations (Sabbi+, 2018)J/ApJ/859/L8 : Properties of TriAnd stars (Hayes+, 2018)J/ApJ/886/61 : OGLE-III, MCPS and HST VI obs. of LMC & SMC (Yuan+, 2019)http://acszeropoints.stsci.edu/ : ACS zeropoint online calculatorhttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/906/125https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/906/125http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/906/125https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/906/125https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/906/125http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/906/125GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/906/125/table1 (Archival HST/ACS images used in this study)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/906/125/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/906/125/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/906/125/table1?GETtext/xml+votable180.050000true184.826291747.33605560.005555555555555556Cone search capability for table J/ApJ/906/125/table3 (A List of bright and isolated stars used for the aperture correction)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/906/125/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/906/125/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/906/125/table3?GETtext/xml+votable180.050000true184.7854916747.3313750.0055555555555555566/10977 109802.3657755224268815e-19 3.829809573510641e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/906/125?format=asciiOpticaldefaultJ/ApJ/906/125/table1Archival HST/ACS images used in this studyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFieldField identifiermeta.id;obs.fieldcharRAJ2000[12] Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000[47] Degree of declination (J2000)pos.eq.dec;meta.mainRad[4.2/10.5] Radiusarcminphys.angSizefloata[11/24.8] Semimajor axis (1)arcminphys.angSizefloatLEDA[24.3/54.7] HyperLEDA (2)kpcphys.angSizefloatTexp555[900/5700] Exposure time for F555Wstime.duration;obs.exposureintTexp814[900/2600] Exposure time for F814Wstime.duration;obs.exposureintObs[2003/2005] Year of observationtime.epochF555-0[25.7/25.8] Zero points for F555W (3)phys.angSizefloatF814-0[25.5/25.6] Zero points for F814W (3)phys.angSizefloatPropID[9477/10399] Prop.IDmeta.id;meta.fileintJ/ApJ/906/125/table3A List of bright and isolated stars used for the aperture correctionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/75] Identifier numbermeta.id;meta.mainintRAJ2000[12] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[47] Degree of Declination (J2000)pos.eq.dec;meta.mainF814W[18.58/23.5]? HST/ACS F814W filter magnitude (1)magphot.mag;em.opt.Ifloatnullablee_F814W[0.001/0.03]? Uncertainty in F814Wmagstat.errorfloatnullableo_F814W[1/11]? Number of independent measurements from different FLC frames in F814Wmeta.numberintnullablestd814W[0/0.06]? Standard deviation of independent measurements in F814Wstat.stdevfloatnullableF555W[18.911/24.6]? HST/ACS F555W filt magnitude (1)magphot.mag;em.opt.Vfloatnullablee_F555W[0.001/0.02]? Uncertainty in F555Wmagstat.errorfloatnullableo_F555W[1/11]? Number of independent measurements from different FLC frames in F555Wmeta.numberintnullablestd555W[0/0.05]? Standard deviation of independent measurements in F555Wstat.stdevfloatnullable