J/AJ/164/20ivo://CDS.VizieR/J/AJ/164/20doi:10.26093/cds/vizier.51640020CDSEscala I.Gilbert K.M.Fardal M.Guhathakurta P.Sanderson R.E.,Kalirai J.S.Mobasher B.2024-11-12T20:09:15Z2022-11-04T07:10:20ZCDS support team

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

cds-question@unistra.frgiant-starsvisible-astronomyspectroscopyradial-velocityWe obtained Keck/DEIMOS spectra of 556 individual red giant branch stars in four spectroscopic fields spanning 13-31 projected kpc along the northeast (NE) shelf of M31. We present the first detection of a complete wedge pattern in the space of projected M31-centric radial distance versus line-of-sight velocity for this feature, which includes the returning stream component of the shelf. This wedge pattern agrees with expectations of a tidal shell formed in a radial merger and provides strong evidence in favor of predictions of Giant Stellar Stream (GSS) formation models in which the NE shelf originates from the second orbital wrap of the tidal debris. The observed concentric wedge patterns of the NE, west (W), and southeast (SE) shelves corroborate this interpretation independently of the models. We do not detect a kinematical signature in the NE shelf region corresponding to an intact progenitor core, favoring GSS formation models in which the progenitor is completely disrupted. The shelf's photometric metallicity ([Fe/H]_phot_) distribution implies that it is dominated by tidal material, as opposed to the phase-mixed stellar halo or the disk. The metallicity distribution ([Fe/H]_phot_=-0.42{+/-}0.01) also matches the GSS, and consequently the W and SE shelves, further supporting a direct physical association between the tidal features.2022AJ....164...20Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/164/20CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/369/120 : Kinematic survey of planetary nebulae in M31 (Merrett+, 2006)J/ApJ/663/960 : Radial velocities of Leo I stars (Sohn+, 2007)J/ApJ/748/29 : Spectroscopy of M87 globular clusters (Romanowsky+, 2012)J/ApJ/752/45 : SPLASH Stellar spectroscopy of M31 satellites (Tollerud+, 2012)J/ApJ/765/28 : CFHTLS galaxies with faint tidal features (Atkinson+, 2013)J/MNRAS/442/3544 : Kinematic tracers in Umbrella galaxy (Foster+, 2014)J/ApJS/215/9 : PHAT X. UV-IR photometry of M31 stars (Williams+, 2014)J/ApJ/868/55 : Large-scale structure M31 halo. II. PAndAS (McConnachie+, 2018)J/ApJ/883/128 : alpha & Fe abundances in giant stellar stream (Gilbert+, 2019)J/ApJ/889/177 : RGB abundances in disk, stream & halo of M31 (Escala+, 2020)J/ApJ/902/51 : Abundances for M31 RGB stars from Keck/DEIMOS (Escala+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/164/20https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/164/20http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/164/20https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/164/20https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/164/20http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/164/20GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/164/20/table2 (Catalog of velocity measurements for M31 RGB stars in the northeast shelf fields)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/164/20/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/164/20/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/164/20/table2?GETtext/xml+votable180.050000true13.1502542.13730560.0055555555555555565/666 6/2668https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/164/20?format=asciiOpticaldefaultJ/AJ/164/20/table2Catalog of velocity measurements for M31 RGB stars in the northeast shelf fieldsDEJ2000[41/42] Degree of Declination (J2000)pos.eq.dec;meta.mainVmag[22.1/24.4] Extinction-corrected V-band Vega magnitudemagphot.mag;em.opt.VfloatImag[20.1/22.4] Extinction-corrected I-band Vega magnitudemagphot.mag;em.opt.Ifloate_Vmag[0.01/0.2] Uncertainty in Vmagmagstat.error;phot.magfloate_Imag[0.01/0.2] Uncertainty in Imagmagstat.error;phot.magfloatRVel[-541/-100] Heliocentric velocity (1)km/sspect.dopplerVeloc;pos.heliocentricfloate_RVel[2/21] Uncertainty in RVelkm/sstat.error;spect.dopplerVelocfloatSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDObject identifiermeta.id;meta.mainintRAJ2000[00] Hour of Right Ascension (J2000)pos.eq.ra;meta.main