J/ApJ/885/53ivo://CDS.VizieR/J/ApJ/885/53doi:10.26093/cds/vizier.18850053CDSMutlu-Pakdil B.Sand D.J.Walker M.G.Caldwell N.Carlin J.L.,Collins M.L.Crnojevic D.Mateo M.Olszewski E.W.Seth A.C.Strader J.,Willman B.Zaritsky D.2022-11-08T07:18:01Z2021-06-21T07:24:06ZCDS support team

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

cds-question@unistra.frgalaxieshst-photometryvisible-astronomyspectroscopyextinctioneffective-temperaturemetallicityThe ultra-faint dwarf galaxy Leo V has shown both photometric overdensities and kinematic members at large radii, along with a tentative kinematic gradient, suggesting that it may have undergone a close encounter with the Milky Way. We investigate these signs of disruption through a combination of (I) high precision photometry obtained with the Hubble Space Telescope (HST), (II) two epochs of stellar spectra obtained with the Hectochelle Spectrograph on the MMT, and (III) measurements from the Gaia mission. Using the HST data, we examine one of the reported stream-like overdensities at large radii, and conclude that it is not a true stellar stream, but instead a clump of foreground stars and background galaxies. Our spectroscopic analysis shows that one known member star is likely a binary, and challenges the membership status of three others, including two distant candidates that had formerly provided evidence for overall stellar mass loss. We also find evidence that the proposed kinematic gradient across Leo V might be due to small number statistics. We update the systemic proper motion of Leo V, finding ({mu}_{alpha}_/cos{delta},{mu}_{delta}_)= (0.009{+/-}0.560,-0.777{+/-}0 .314)mas/yr, which is consistent with its reported orbit that did not put Leo V at risk of being disturbed by the Milky Way. These findings remove most of the observational clues that suggested Leo V was disrupting; however, we also find new plausible member stars, two of which are located >5 half-light radii from the main body. These stars require further investigation. Therefore, the nature of Leo V still remains an open question.2019ApJ...885...53Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/885/53CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/130/1693 : HST-ACS observations of 5 globular clusters (Brown+, 2005)J/AJ/129/2714 : JHK photometry of M92 variable stars (Del Principe+, 2005)J/AJ/136/2050 : SEGUE stellar parameter pipeline. II. (Lee+, 2008)J/ApJ/675/201 : Radial velocities of stars near Leo I (Mateo+, 2008)J/MNRAS/397/1748 : Spectroscopic study of Segue 2 (Belokurov+, 2009)J/ApJ/704/898 : Photometry of the Hercules dwarf galaxy (Sand+, 2009)J/ApJ/694/L144 : Spectroscopic study of Leo V dSph (Walker+, 2009)J/ApJ/710/1664 : BV photometry in Leo IV and Leo V dSphs (de Jong+, 2010)J/ApJ/718/530 : Leo IV g- and r-band photometry (Sand+, 2010)J/AJ/142/22 : Heavy-element dispersion in M92 (Roederer+, 2011)J/ApJ/756/79 : Optical photometry 3 Local Group dwarf galaxies (Sand+, 2012)J/ApJ/770/16 : Spectroscopic members of Segue 2 galaxy (Kirby+, 2013)J/MNRAS/448/2717 : Bayesian analysis of resolved stellar spectra (Walker+,2015)J/AJ/154/155 : Abundance variations in outer halo GC NGC6229 (Johnson+, 2017)J/ApJ/838/83 : RVel, abundances & membership in TriII (Kirby+, 2017)J/ApJ/838/11 : Member stars in the MW satellite Tucana III (Simon+, 2017)J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)J/ApJ/866/22 : Spectroscopic analysis of Tuc III stream (Li+, 2018)J/ApJ/863/25 : Deep Magellan/Megacam obs. 4 MWsatellites (Mutlu-Pakdil+,2018)J/ApJ/863/89 : Gaia DR2 PMs of stars ultra-faint MW satellites (Simon, 2018)J/ApJ/883/11 : Magellan/IMACS spectra of Crater II & Hercules (Fu+, 2019)J/ApJ/870/83 : Abundances in ultra-faint dwarf gal. GruI & TriII (Ji+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/885/53https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/885/53http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/885/53https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/885/53https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/885/53http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/885/53GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/885/53/table2 (Photometry of field 1-ACS: central pointing of Leo V)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/885/53/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/885/53/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/885/53/table2?GETtext/xml+votable180.050000true172.8062.22298250.005555555555555556Cone search capability for table J/ApJ/885/53/table3 (Photometry of field 2-ACS: candidate debris stream of Leo V)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/885/53/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/885/53/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/885/53/table3?GETtext/xml+votable180.050000true172.843642.29018510.005555555555555556Cone search capability for table J/ApJ/885/53/table4 (Photometry of field 1-WFC3: parallel observations of Leo V with WFC3)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/885/53/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/885/53/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/885/53/table4?GETtext/xml+votable180.050000true172.864262.14263870.005555555555555556Cone search capability for table J/ApJ/885/53/table5 (Photometry of field 2-WFC3: parallel observations of candidate debris stream of Leo V with WFC3)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/885/53/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/885/53/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/885/53/table5?GETtext/xml+votable180.050000true172.933322.22781480.005555555555555556Cone search capability for table J/ApJ/885/53/table6 (Hectochelle stellar spectroscopy of Leo V)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/885/53/table6?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/885/53/table6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/885/53/table6?GETtext/xml+votable180.050000true172.528752.123670.0055555555555555565/6750 6/2.238682544986967e-19 3.999628114029321e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/885/53?format=asciiOpticaldefaultJ/ApJ/885/53/table2Photometry of field 1-ACS: central pointing of Leo VSeq[0/2465] Internal star identifiermeta.idintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[172.75/172.82] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[2.18/2.26] Declination (J2000)degpos.eq.dec;meta.mainF606Wmag[19.09/28.5] HST/ACS F606W band magnitudemagphot.mag;em.opt.Rfloate_F606Wmag[0.001/0.3] DOLPHOT uncertainty in F606Wmagmagstat.errorfloatAF606W[0.06/0.07] Galactic extinction in F606Wmagphys.absorptionfloatF814Wmag[17.61/27.72] HST/ACS F814W band magnitudemagphot.mag;em.opt.Ifloate_F814Wmag[0.001/0.3] DOLPHOT uncertainty in F814Wmagmagstat.errorfloatAF814W[0.04/0.05] Galactic extinction in F814Wmagphys.absorptionfloatJ/ApJ/885/53/table3Photometry of field 2-ACS: candidate debris stream of Leo VrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[0/1230] Internal star identifiermeta.idintRAJ2000[172.84/172.91] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[2.27/2.34] Declination (J2000)degpos.eq.dec;meta.mainF606Wmag[20.15/28.53] HST/ACS F606W band magnitudemagphot.mag;em.opt.Rfloate_F606Wmag[0.001/0.22] DOLPHOT uncertainty in F606Wmagmagstat.errorfloatAF606W[0.06/0.071] Galactic extinction in F606Wmagphys.absorptionfloatF814Wmag[18.6/27.65] HST/ACS F814W band magnitudemagphot.mag;em.opt.Ifloate_F814Wmag[0.001/0.3] DOLPHOT uncertainty in F814Wmagmagstat.errorfloatAF814W[0.03/0.05] Galactic extinction in F814Wmagphys.absorptionfloatJ/ApJ/885/53/table4Photometry of field 1-WFC3: parallel observations of Leo V with WFC3Seq[0/537] Internal star identifiermeta.idintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[172.83/172.90] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[2.12/2.19] Declination (J2000)degpos.eq.dec;meta.mainF606Wmag[21.01/28.4] HST/WFC3 F606W band magnitudemagphot.mag;em.opt.Rfloate_F606Wmag[0.002/0.3] DOLPHOT uncertainty in F606Wmagmagstat.errorfloatAF606W[0.06/0.07] Galactic extinction in F606Wmagphys.absorptionfloatF814Wmag[20.49/27.28] HST/WFC3 F814W band magnitudemagphot.mag;em.opt.Ifloate_F814Wmag[0.003/0.3] DOLPHOT uncertainty in F814Wmagmagstat.errorfloatAF814W[0.04/0.05] Galactic extinction in F814Wmagphys.absorptionfloatJ/ApJ/885/53/table5Photometry of field 2-WFC3: parallel observations of candidate debris stream of Leo V with WFC3recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[0/415] Internal star identifiermeta.idintRAJ2000[172.90/172.97] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[2.20/2.26] Declination (J2000)degpos.eq.dec;meta.mainF606Wmag[21.27/28.44] HST/WFC3 F606W band magnitudemagphot.mag;em.opt.Rfloate_F606Wmag[0.002/0.3] DOLPHOT uncertainty in F606Wmagmagstat.errorfloatAF606W[0.072/0.073] Galactic extinction in F606Wmagphys.absorptionfloatF814Wmag[19.44/27.36] HST/WFC3 F814W band magnitudemagphot.mag;em.opt.Ifloate_F814Wmag[0.002/0.3] DOLPHOT uncertainty in F814Wmagmagstat.errorfloatAF814W[0.044/0.045] Galactic extinction in F814Wmagphys.absorptionfloatJ/ApJ/885/53/table6Hectochelle stellar spectroscopy of Leo Ve_Vel[0.3/3.6] Uncertainty in Velkm/sstat.errorfloatTeff[4039/5970] Effective temperatureKphys.temperature.effectiveintSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar identifiermeta.id;meta.maincharRAJ2000[172.31/173.27] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[1.77/2.66] Declination (J2000)degpos.eq.dec;meta.mainHJD[4614/49128] Heliocentric Julian Date; HJD-2450000.0dtime.epochfloatVel[-120/345] Line-of-Sight velocity; solar rest framekm/sphys.velocfloate_Teff[33/951] Uncertainty in TeffKstat.error;phys.temperature.effectiveintlogg[0.66/4.81] log surface gravitylog(cm.s**-2)phys.gravityfloate_logg[0.1/1.3] Uncertainty in logglog(cm.s**-2)stat.errorfloat[Fe/H][-2.9/0.62] Metallicityphys.abund.Zfloate_[Fe/H][0.05/0.98] Uncertainty in [Fe/H]stat.error;phys.abund.Fefloat