J/MNRAS/516/2348ivo://CDS.VizieR/J/MNRAS/516/2348doi:10.26093/cds/vizier/bg-g4-29cCDSLongeard N.Jablonka P.Arentsen A.Thomas G.F.Aguado D.S.,Carlberg R.G.Lucchesi R.Malhan K.Martin N.Mcconnachie A.W.,Navarro J.F.Sanchez-Janssen R.Sestito F.Starkenburg E.Yuan Z.2026-08-03T07:31:48Z2025-10-03T16:25:24ZCDS support team

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

cds-question@unistra.frgalaxiesdwarf-galaxieschemically-peculiar-starsstellar-populationsspectroscopyspectrophotometryvisible-astronomyastrometryphotometryproper-motionsmetallicityWe present a new spectroscopic study of the dwarf galaxy Bootes I (Boo I) with data from the Anglo-Australian Telescope and its AAOmega spectrograph together with the Two Degree Field multi-object system. We observed 36 high-probability Boo I stars selected using Gaia Early Data Release 3 proper motions and photometric metallicities from the Pristine survey. Out of those, 27 are found to be Boo I stars, resulting in an excellent success rate of 75 per cent at finding new members. Our analysis uses a new pipeline developed to estimate radial velocities and equivalent widths of the calcium triplet lines from Gaussian and Voigt line profile fits. The metallicities of 16 members are derived, including 3 extremely metal-poor stars ([Fe/H] < -3.0), which translates into a success rate of 25 per cent at finding them with the combination of Pristine and Gaia. Using the large spatial extent of our new members that spans up to 4.1 half-light radii and spectroscopy from the literature, we find a systemic velocity gradient of 0.40 +/- 0.10 km.s^-1^.arcmin^-1^ and a small but resolved metallicity gradient of -0.008 +/- 0.003 dex.arcmin^-1^. Finally, we show that Boo I is more elongated than previously thought with an ellipticity of {epsilon} = 0.68 +/- 0.15. Its velocity and metallicity gradients as well as its elongation suggest that Boo I may have been affected by tides, a result supported by direct dynamical modelling.2022MNRAS.516.2348Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/516/2348CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/380/281 : Faint galactic satellites spectroscopic surveyJ/MNRAS/490/2241 : Spectroscopy of Pristine EMP star candidates (Aguado+, 2019)J/MNRAS/472/2963 : Metallicities of Pristine stars (Youakim+, 2017)J/MNRAS/490/3508 : The Southern Stellar Stream Sp. Survey (S^5^) (Li+, 2019)J/MNRAS/383/183 : CaII triplet of RGB from VLT/FLAMES obs. (Battaglia+, 2008)J/MNRAS/491/356 : Sagittarius II study with the Pristine surveyJ/MNRAS/458/L59 : Draco II stars gi magnitude & radial velocitiesJ/MNRAS/466/2006 : Phoenix dwarf galaxy RV and [Fe/H] catalog (Kacharov+, 2017)J/MNRAS/434/1681 : Extremely metal-poor stars CaII triplet (Carrera+, 2013)J/A+A/623/A129 : New satellites of the LMC search (Fritz+, 2019)J/A+A/562/A146 : Chemical abundances of 8 metal-poor stars (Ishigaki+, 2014)J/A+A/657/A54 : Local Group Gaia eDR3 systemic motions (Battaglia+, 2022)J/A+A/608/A89 : Very metal poor stars in MW halo (Mashonkina+, 2017)J/A+A/544/A73 : BVI photometry of Fornax dSph galaxy (de Boer+, 2012)J/ApJ/770/16 : Spectroscopic members of Segue 2 galaxy (Kirby+, 2013)J/ApJ/920/92 : VLT Spectroscopy of Ultra-faint Dwarf GalaxiesJ/ApJ/723/1632 : Abundance spreads in Bootes I and Segue 1 (Norris+, 2010)J/ApJ/826/110 : Boo-127 and Boo-980 high-resolution spectra (Frebel+, 2016)J/ApJ/763/61 : Abundances of 7 red giant members of BootesI (Gilmore+,2013)J/ApJ/711/350 : Metal-poor giant Boo-1137 abundances (Norris+, 2010)J/ApJ/736/146 : Radial velocities of stars in Bootes I (Koposov+, 2011)J/AJ/144/4 : Properties of dwarf galaxies in the Local GroupII/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+,2016)I/350 : Gaia EDR3 (Gaia Collaboration, 2020)I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/516/2348https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/516/2348http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/516/2348https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/516/2348https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/516/2348http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/516/2348GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/516/2348/table1 (Properties and estimated metallicities of the new AAT spectroscopic Boo I sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/516/2348/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/516/2348/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/516/2348/table1?GETtext/xml+votable180.050000true209.9588714.3290.005555555555555556Cone search capability for table J/MNRAS/516/2348/table2 (Previous literature members that are found not to be Boo I members after reanalysis)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/516/2348/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/516/2348/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/516/2348/table2?GETtext/xml+votable180.050000true209.961514.520610.0055555555555555565/2186 6/8738-8739 8742 8748 8750https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/516/2348?format=asciiOpticaldefaultJ/MNRAS/516/2348/table1Properties and estimated metallicities of the new AAT spectroscopic Boo I samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (Dec)degpos.eq.dec;meta.maing0magExtinction corrected SDSS g magnitude (g_0_)magphot.mag;em.opt.B;arith.difffloate_g0magUncertainty of g0mag (errg_0_)magstat.error;phot.magfloati0magExtinction corrected SDSS i magnitude (i_0_)magphot.mag;em.opt.I;arith.difffloatSimbadNameSimbad column added by the CDSmeta.idcharnullablee_i0magUncertainty of i0mag (erri_0_)magstat.error;phot.magfloatCaHK0magExtinction corrected of calcium H&K lines magnitude centered around ~3933 {AA} and ~3968 {AA} from AAT pristine obs. (CaHK_0_)magphot.mag;em.opt;arith.difffloate_CaHK0magUncertainty of CaHK0mag (errCaHK_0_)magstat.error;phot.magfloatRVRadial velocity computed from observed spectrum (v_r_)km/sspect.dopplerVeloc;meta.modelled;obsfloate_RVUncertainty of RV (errv_r_)km/sstat.errorfloatpmRA? Proper motion in right ascension direction from observed spectrum and GaiaDR3 ({mu}^*^_{alpha}_)mas/yrpos.pm;pos.eq.rafloatnullablee_pmRA? Uncertainty of pmRA (err{mu}^*^_{alpha}_)mas/yrstat.error;pos.pm;pos.eq.rafloatnullablepmDE? Proper motion in declination direction from observed spectrum and GaiaDR3 ({mu}_{delta}_)mas/yrpos.pm;pos.eq.decfloatnullablee_pmDE? Uncertainty of pmDE (err{mu}_{delta}_)mas/yrstat.error;pos.pm;pos.eq.decfloatnullableS/NSignal to noise ratio from observations (S/N)stat.snr;obsfloat[Fe/H]GJ/MNRAS/516/2348/table2Previous literature members that are found not to be Boo I members after reanalysis[Fe/H]