A radial velocity survey of low galactic latitude structures - : I. Kinematics of the Canis Major dwarf galaxy
Identifieur interne : 004776 ( PascalFrancis/Corpus ); précédent : 004775; suivant : 004777A radial velocity survey of low galactic latitude structures - : I. Kinematics of the Canis Major dwarf galaxy
Auteurs : N. F. Martin ; R. A. Ibata ; B. C. Conn ; G. F. Lewis ; M. Bellazzini ; M. J. IrwinSource :
- Monthly Notices of the Royal Astronomical Society [ 0035-8711 ] ; 2005.
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Abstract
As part of a radial velocity survey of low Galactic latitude structures that we undertook with the 2dF spectrograph on the Anglo-Australian Telescope, we present the radial velocities of more than 1500 red giant branch and red clump stars towards the centre of the Canis Major dwarf galaxy. With a mean velocity of 72 ± 7 km s-1 at a heliocentric distance of 5.5 kpc and 114 ± 2 km s-1 at 8.5 kpc, these stars present a peculiar distance - radial velocity relation that is unlike that expected from thin or thick disc stars. Moreover, they belong to a kinematically cold population with an intrinsic dispersion that may be as low as 11+3-1 km s-1. A comparison of the velocity distribution obtained in this work with previous studies shows the importance of using our new reduction pipeline and averaging the velocities obtained from different templates. The radial velocity distribution is used to select Canis Major stars in the UCAC2.0 proper motion catalogue and derive proper motions in Galactic coordinates of (μl, μb) = (-3.6 ± 0.8 mas yr-1, 1.5 ± 0.4 mas yr-1) for the dwarf galaxy, which after correcting for the reflex solar motion along this line of sight gives (μ'l, μ'b) = (-6.8 ± 0.8 mas yr-1, 0.8 ± 0.4 mas yr-1), corresponding to a prograde orbit with a tangential velocity of ∼235 km s-1 at the average distance of ∼7.2 kpc. All these kinematic constraints can be reproduced in simulations of the accretion of a dwarf on to the Galactic disc. Such a process could also be responsible for the Monoceros Ring that has recently been shown to encompass the Galactic disc. However, without constraints on the kinematics of the tidal arms emerging from the Canis Major dwarf, it is not yet possible to definitively prove a link between the two structures.
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| NO : | PASCAL 05-0403231 INIST |
|---|---|
| ET : | A radial velocity survey of low galactic latitude structures - : I. Kinematics of the Canis Major dwarf galaxy |
| AU : | MARTIN (N. F.); IBATA (R. A.); CONN (B. C.); LEWIS (G. F.); BELLAZZINI (M.); IRWIN (M. J.) |
| AF : | Observatoire de Strasbourg, 11, rue de l'Université/67000, Strasbourg/France (1 aut., 2 aut.); Institute of Astronomy, School of Physics, A29, University of Sydney/NSW 2006/Australie (3 aut., 4 aut.); INAF - Osservatorio Astronomico di Bologna, Via Ranzani 1/Italie (5 aut.); Institute of Astronomy, Madingley Road/Cambridge CB3 0HA/Royaume-Uni (6 aut.) |
| DT : | Publication en série; Niveau analytique |
| SO : | Monthly Notices of the Royal Astronomical Society; ISSN 0035-8711; Coden MNRAA4; Royaume-Uni; Da. 2005; Vol. 362; No. 3; Pp. 906-914; Bibl. 31 ref. |
| LA : | Anglais |
| EA : | As part of a radial velocity survey of low Galactic latitude structures that we undertook with the 2dF spectrograph on the Anglo-Australian Telescope, we present the radial velocities of more than 1500 red giant branch and red clump stars towards the centre of the Canis Major dwarf galaxy. With a mean velocity of 72 ± 7 km s-1 at a heliocentric distance of 5.5 kpc and 114 ± 2 km s-1 at 8.5 kpc, these stars present a peculiar distance - radial velocity relation that is unlike that expected from thin or thick disc stars. Moreover, they belong to a kinematically cold population with an intrinsic dispersion that may be as low as 11+3-1 km s-1. A comparison of the velocity distribution obtained in this work with previous studies shows the importance of using our new reduction pipeline and averaging the velocities obtained from different templates. The radial velocity distribution is used to select Canis Major stars in the UCAC2.0 proper motion catalogue and derive proper motions in Galactic coordinates of (μl, μb) = (-3.6 ± 0.8 mas yr-1, 1.5 ± 0.4 mas yr-1) for the dwarf galaxy, which after correcting for the reflex solar motion along this line of sight gives (μ'l, μ'b) = (-6.8 ± 0.8 mas yr-1, 0.8 ± 0.4 mas yr-1), corresponding to a prograde orbit with a tangential velocity of ∼235 km s-1 at the average distance of ∼7.2 kpc. All these kinematic constraints can be reproduced in simulations of the accretion of a dwarf on to the Galactic disc. Such a process could also be responsible for the Monoceros Ring that has recently been shown to encompass the Galactic disc. However, without constraints on the kinematics of the tidal arms emerging from the Canis Major dwarf, it is not yet possible to definitively prove a link between the two structures. |
| CC : | 001E03 |
| FD : | Vitesse radiale; Structure galactique; Cinématique; Galaxies naines; Géante rouge; Distance héliocentrique; Etoile particulière; Distribution vitesse; Distribution radiale; Mouvement propre; Catalogue astronomique; Orbite; Accrétion; Disque galactique; Voie lactée; Structure galaxies |
| ED : | Radial velocity; Galactic structure; Kinematics; Dwarf galaxies; Red giant stars; Heliocentric distance; Peculiar stars; Velocity distribution; Radial distribution; Proper motion; Astronomical catalogues; Orbits; Accretion; Galactic disks; Milky Way; Galaxy structure |
| SD : | Distancia heliocéntrica; Distribución radial; Estructura galaxias |
| LO : | INIST-2067.354000131889180140 |
| ID : | 05-0403231 |
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Soc.</title><idno type="ISSN">0035-8711</idno></seriesStmt></fileDesc><profileDesc><textClass><keywords scheme="KwdEn" xml:lang="en"><term>Accretion</term><term>Astronomical catalogues</term><term>Dwarf galaxies</term><term>Galactic disks</term><term>Galactic structure</term><term>Galaxy structure</term><term>Heliocentric distance</term><term>Kinematics</term><term>Milky Way</term><term>Orbits</term><term>Peculiar stars</term><term>Proper motion</term><term>Radial distribution</term><term>Radial velocity</term><term>Red giant stars</term><term>Velocity distribution</term></keywords><keywords scheme="Pascal" xml:lang="fr"><term>Vitesse radiale</term><term>Structure galactique</term><term>Cinématique</term><term>Galaxies naines</term><term>Géante rouge</term><term>Distance héliocentrique</term><term>Etoile particulière</term><term>Distribution vitesse</term><term>Distribution radiale</term><term>Mouvement propre</term><term>Catalogue astronomique</term><term>Orbite</term><term>Accrétion</term><term>Disque galactique</term><term>Voie lactée</term><term>Structure galaxies</term></keywords></textClass></profileDesc></teiHeader><front><div type="abstract" xml:lang="en">As part of a radial velocity survey of low Galactic latitude structures that we undertook with the 2dF spectrograph on the Anglo-Australian Telescope, we present the radial velocities of more than 1500 red giant branch and red clump stars towards the centre of the Canis Major dwarf galaxy. With a mean velocity of 72 ± 7 km s<sup>-1</sup> at a heliocentric distance of 5.5 kpc and 114 ± 2 km s<sup>-1</sup> at 8.5 kpc, these stars present a peculiar distance - radial velocity relation that is unlike that expected from thin or thick disc stars. Moreover, they belong to a kinematically cold population with an intrinsic dispersion that may be as low as 11<sup>+3</sup><sub>-1</sub> km s<sup>-1</sup>. A comparison of the velocity distribution obtained in this work with previous studies shows the importance of using our new reduction pipeline and averaging the velocities obtained from different templates. The radial velocity distribution is used to select Canis Major stars in the UCAC2.0 proper motion catalogue and derive proper motions in Galactic coordinates of (μ<sub>l</sub>, μ<sub>b</sub>) = (-3.6 ± 0.8 mas yr<sup>-1</sup>, 1.5 ± 0.4 mas yr<sup>-1</sup>) for the dwarf galaxy, which after correcting for the reflex solar motion along this line of sight gives (μ'<sub>l</sub>, μ'<sub>b</sub>) = (-6.8 ± 0.8 mas yr<sup>-1</sup>, 0.8 ± 0.4 mas yr<sup>-1</sup>), corresponding to a prograde orbit with a tangential velocity of ∼235 km s<sup>-1</sup> at the average distance of ∼7.2 kpc. All these kinematic constraints can be reproduced in simulations of the accretion of a dwarf on to the Galactic disc. Such a process could also be responsible for the Monoceros Ring that has recently been shown to encompass the Galactic disc. However, without constraints on the kinematics of the tidal arms emerging from the Canis Major dwarf, it is not yet possible to definitively prove a link between the two structures.</div></front></TEI><inist><standard h6="B"><pA><fA01 i1="01" i2="1"><s0>0035-8711</s0></fA01><fA02 i1="01"><s0>MNRAA4</s0></fA02><fA03 i2="1"><s0>Mon. Not. R. Astron. Soc.</s0></fA03><fA05><s2>362</s2></fA05><fA06><s2>3</s2></fA06><fA08 i1="01" i2="1" l="ENG"><s1>A radial velocity survey of low galactic latitude structures - : I. Kinematics of the Canis Major dwarf galaxy</s1></fA08><fA11 i1="01" i2="1"><s1>MARTIN (N. F.)</s1></fA11><fA11 i1="02" i2="1"><s1>IBATA (R. A.)</s1></fA11><fA11 i1="03" i2="1"><s1>CONN (B. C.)</s1></fA11><fA11 i1="04" i2="1"><s1>LEWIS (G. F.)</s1></fA11><fA11 i1="05" i2="1"><s1>BELLAZZINI (M.)</s1></fA11><fA11 i1="06" i2="1"><s1>IRWIN (M. J.)</s1></fA11><fA14 i1="01"><s1>Observatoire de Strasbourg, 11, rue de l'Université</s1><s2>67000, Strasbourg</s2><s3>FRA</s3><sZ>1 aut.</sZ><sZ>2 aut.</sZ></fA14><fA14 i1="02"><s1>Institute of Astronomy, School of Physics, A29, University of Sydney</s1><s2>NSW 2006</s2><s3>AUS</s3><sZ>3 aut.</sZ><sZ>4 aut.</sZ></fA14><fA14 i1="03"><s1>INAF - Osservatorio Astronomico di Bologna, Via Ranzani 1</s1><s3>ITA</s3><sZ>5 aut.</sZ></fA14><fA14 i1="04"><s1>Institute of Astronomy, Madingley Road</s1><s2>Cambridge CB3 0HA</s2><s3>GBR</s3><sZ>6 aut.</sZ></fA14><fA20><s1>906-914</s1></fA20><fA21><s1>2005</s1></fA21><fA23 i1="01"><s0>ENG</s0></fA23><fA43 i1="01"><s1>INIST</s1><s2>2067</s2><s5>354000131889180140</s5></fA43><fA44><s0>0000</s0><s1>© 2005 INIST-CNRS. All rights reserved.</s1></fA44><fA45><s0>31 ref.</s0></fA45><fA47 i1="01" i2="1"><s0>05-0403231</s0></fA47><fA60><s1>P</s1></fA60><fA61><s0>A</s0></fA61><fA64 i1="01" i2="1"><s0>Monthly Notices of the Royal Astronomical Society</s0></fA64><fA66 i1="01"><s0>GBR</s0></fA66><fC01 i1="01" l="ENG"><s0>As part of a radial velocity survey of low Galactic latitude structures that we undertook with the 2dF spectrograph on the Anglo-Australian Telescope, we present the radial velocities of more than 1500 red giant branch and red clump stars towards the centre of the Canis Major dwarf galaxy. With a mean velocity of 72 ± 7 km s<sup>-1</sup> at a heliocentric distance of 5.5 kpc and 114 ± 2 km s<sup>-1</sup> at 8.5 kpc, these stars present a peculiar distance - radial velocity relation that is unlike that expected from thin or thick disc stars. Moreover, they belong to a kinematically cold population with an intrinsic dispersion that may be as low as 11<sup>+3</sup><sub>-1</sub> km s<sup>-1</sup>. A comparison of the velocity distribution obtained in this work with previous studies shows the importance of using our new reduction pipeline and averaging the velocities obtained from different templates. The radial velocity distribution is used to select Canis Major stars in the UCAC2.0 proper motion catalogue and derive proper motions in Galactic coordinates of (μ<sub>l</sub>, μ<sub>b</sub>) = (-3.6 ± 0.8 mas yr<sup>-1</sup>, 1.5 ± 0.4 mas yr<sup>-1</sup>) for the dwarf galaxy, which after correcting for the reflex solar motion along this line of sight gives (μ'<sub>l</sub>, μ'<sub>b</sub>) = (-6.8 ± 0.8 mas yr<sup>-1</sup>, 0.8 ± 0.4 mas yr<sup>-1</sup>), corresponding to a prograde orbit with a tangential velocity of ∼235 km s<sup>-1</sup> at the average distance of ∼7.2 kpc. All these kinematic constraints can be reproduced in simulations of the accretion of a dwarf on to the Galactic disc. Such a process could also be responsible for the Monoceros Ring that has recently been shown to encompass the Galactic disc. However, without constraints on the kinematics of the tidal arms emerging from the Canis Major dwarf, it is not yet possible to definitively prove a link between the two structures.</s0></fC01><fC02 i1="01" i2="3"><s0>001E03</s0></fC02><fC03 i1="01" i2="3" l="FRE"><s0>Vitesse radiale</s0><s5>26</s5></fC03><fC03 i1="01" i2="3" l="ENG"><s0>Radial velocity</s0><s5>26</s5></fC03><fC03 i1="02" i2="3" l="FRE"><s0>Structure galactique</s0><s5>27</s5></fC03><fC03 i1="02" i2="3" l="ENG"><s0>Galactic structure</s0><s5>27</s5></fC03><fC03 i1="03" i2="3" l="FRE"><s0>Cinématique</s0><s5>28</s5></fC03><fC03 i1="03" i2="3" l="ENG"><s0>Kinematics</s0><s5>28</s5></fC03><fC03 i1="04" i2="3" l="FRE"><s0>Galaxies naines</s0><s5>29</s5></fC03><fC03 i1="04" i2="3" l="ENG"><s0>Dwarf galaxies</s0><s5>29</s5></fC03><fC03 i1="05" i2="3" l="FRE"><s0>Géante rouge</s0><s5>30</s5></fC03><fC03 i1="05" i2="3" l="ENG"><s0>Red giant stars</s0><s5>30</s5></fC03><fC03 i1="06" i2="X" l="FRE"><s0>Distance héliocentrique</s0><s5>31</s5></fC03><fC03 i1="06" i2="X" l="ENG"><s0>Heliocentric distance</s0><s5>31</s5></fC03><fC03 i1="06" i2="X" l="SPA"><s0>Distancia heliocéntrica</s0><s5>31</s5></fC03><fC03 i1="07" i2="3" l="FRE"><s0>Etoile particulière</s0><s5>32</s5></fC03><fC03 i1="07" i2="3" l="ENG"><s0>Peculiar stars</s0><s5>32</s5></fC03><fC03 i1="08" i2="3" l="FRE"><s0>Distribution vitesse</s0><s5>33</s5></fC03><fC03 i1="08" i2="3" l="ENG"><s0>Velocity distribution</s0><s5>33</s5></fC03><fC03 i1="09" i2="X" l="FRE"><s0>Distribution radiale</s0><s5>34</s5></fC03><fC03 i1="09" i2="X" l="ENG"><s0>Radial distribution</s0><s5>34</s5></fC03><fC03 i1="09" i2="X" l="SPA"><s0>Distribución radial</s0><s5>34</s5></fC03><fC03 i1="10" i2="3" l="FRE"><s0>Mouvement propre</s0><s5>35</s5></fC03><fC03 i1="10" i2="3" l="ENG"><s0>Proper motion</s0><s5>35</s5></fC03><fC03 i1="11" i2="3" l="FRE"><s0>Catalogue astronomique</s0><s5>36</s5></fC03><fC03 i1="11" i2="3" l="ENG"><s0>Astronomical catalogues</s0><s5>36</s5></fC03><fC03 i1="12" i2="3" l="FRE"><s0>Orbite</s0><s5>37</s5></fC03><fC03 i1="12" i2="3" l="ENG"><s0>Orbits</s0><s5>37</s5></fC03><fC03 i1="13" i2="3" l="FRE"><s0>Accrétion</s0><s5>38</s5></fC03><fC03 i1="13" i2="3" l="ENG"><s0>Accretion</s0><s5>38</s5></fC03><fC03 i1="14" i2="3" l="FRE"><s0>Disque galactique</s0><s5>39</s5></fC03><fC03 i1="14" i2="3" l="ENG"><s0>Galactic disks</s0><s5>39</s5></fC03><fC03 i1="15" i2="3" l="FRE"><s0>Voie lactée</s0><s5>40</s5></fC03><fC03 i1="15" i2="3" l="ENG"><s0>Milky Way</s0><s5>40</s5></fC03><fC03 i1="16" i2="3" l="FRE"><s0>Structure galaxies</s0><s4>CD</s4><s5>96</s5></fC03><fC03 i1="16" i2="3" l="ENG"><s0>Galaxy structure</s0><s4>CD</s4><s5>96</s5></fC03><fC03 i1="16" i2="3" l="SPA"><s0>Estructura galaxias</s0><s4>CD</s4><s5>96</s5></fC03><fN21><s1>283</s1></fN21><fN44 i1="01"><s1>OTO</s1></fN44><fN82><s1>OTO</s1></fN82></pA></standard><server><NO>PASCAL 05-0403231 INIST</NO><ET>A radial velocity survey of low galactic latitude structures - : I. Kinematics of the Canis Major dwarf galaxy</ET><AU>MARTIN (N. F.); IBATA (R. A.); CONN (B. C.); LEWIS (G. F.); BELLAZZINI (M.); IRWIN (M. J.)</AU><AF>Observatoire de Strasbourg, 11, rue de l'Université/67000, Strasbourg/France (1 aut., 2 aut.); Institute of Astronomy, School of Physics, A29, University of Sydney/NSW 2006/Australie (3 aut., 4 aut.); INAF - Osservatorio Astronomico di Bologna, Via Ranzani 1/Italie (5 aut.); Institute of Astronomy, Madingley Road/Cambridge CB3 0HA/Royaume-Uni (6 aut.)</AF><DT>Publication en série; Niveau analytique</DT><SO>Monthly Notices of the Royal Astronomical Society; ISSN 0035-8711; Coden MNRAA4; Royaume-Uni; Da. 2005; Vol. 362; No. 3; Pp. 906-914; Bibl. 31 ref.</SO><LA>Anglais</LA><EA>As part of a radial velocity survey of low Galactic latitude structures that we undertook with the 2dF spectrograph on the Anglo-Australian Telescope, we present the radial velocities of more than 1500 red giant branch and red clump stars towards the centre of the Canis Major dwarf galaxy. With a mean velocity of 72 ± 7 km s<sup>-1</sup> at a heliocentric distance of 5.5 kpc and 114 ± 2 km s<sup>-1</sup> at 8.5 kpc, these stars present a peculiar distance - radial velocity relation that is unlike that expected from thin or thick disc stars. Moreover, they belong to a kinematically cold population with an intrinsic dispersion that may be as low as 11<sup>+3</sup><sub>-1</sub> km s<sup>-1</sup>. A comparison of the velocity distribution obtained in this work with previous studies shows the importance of using our new reduction pipeline and averaging the velocities obtained from different templates. The radial velocity distribution is used to select Canis Major stars in the UCAC2.0 proper motion catalogue and derive proper motions in Galactic coordinates of (μ<sub>l</sub>, μ<sub>b</sub>) = (-3.6 ± 0.8 mas yr<sup>-1</sup>, 1.5 ± 0.4 mas yr<sup>-1</sup>) for the dwarf galaxy, which after correcting for the reflex solar motion along this line of sight gives (μ'<sub>l</sub>, μ'<sub>b</sub>) = (-6.8 ± 0.8 mas yr<sup>-1</sup>, 0.8 ± 0.4 mas yr<sup>-1</sup>), corresponding to a prograde orbit with a tangential velocity of ∼235 km s<sup>-1</sup> at the average distance of ∼7.2 kpc. All these kinematic constraints can be reproduced in simulations of the accretion of a dwarf on to the Galactic disc. Such a process could also be responsible for the Monoceros Ring that has recently been shown to encompass the Galactic disc. However, without constraints on the kinematics of the tidal arms emerging from the Canis Major dwarf, it is not yet possible to definitively prove a link between the two structures.</EA><CC>001E03</CC><FD>Vitesse radiale; Structure galactique; Cinématique; Galaxies naines; Géante rouge; Distance héliocentrique; Etoile particulière; Distribution vitesse; Distribution radiale; Mouvement propre; Catalogue astronomique; Orbite; Accrétion; Disque galactique; Voie lactée; Structure galaxies</FD><ED>Radial velocity; Galactic structure; Kinematics; Dwarf galaxies; Red giant stars; Heliocentric distance; Peculiar stars; Velocity distribution; Radial distribution; Proper motion; Astronomical catalogues; Orbits; Accretion; Galactic disks; Milky Way; Galaxy structure</ED><SD>Distancia heliocéntrica; Distribución radial; Estructura galaxias</SD><LO>INIST-2067.354000131889180140</LO><ID>05-0403231</ID></server></inist></record>Pour manipuler ce document sous Unix (Dilib)
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