Magellan/M2FS spectroscopy of Tucana 2 and Grus 1 Virtual Observatory Resource

Authors
  1. Walker M.G.
  2. Mateo M.
  3. Olszewski E.W.
  4. Koposov S.
  5. Belokurov V.
  6. Jethwa P.,Nidever D.L.
  7. Bonnivard V.
  8. Bailey III J.I.
  9. Bell E.F.
  10. Loebman S.R.
  11. Published by
    CDS
Abstract

We present results from spectroscopic observations with the Michigan/Magellan Fiber System (M2FS) of 147 stellar targets along the line of sight to the newly discovered "ultrafaint" stellar systems Tucana 2 (Tuc 2) and Grus 1 (Gru 1). Based on simultaneous estimates of line of sight velocity and stellar-atmospheric parameters, we identify 8 and 7 stars as probable members of Tuc 2 and and Gru 1, respectively. Our sample for Tuc 2 is sufficient to resolve an internal velocity dispersion of 8.6^+4.4^_-2.7_km/s about a mean of -129.1+/-3.5km/s (solar rest frame), and to estimate a mean metallicity of [Fe/H]=-2.23^+0.18^_-0.12_. These results place Tuc 2 on chemodynamical scaling relations followed by dwarf galaxies, suggesting a dominant dark matter component with dynamical mass 2.7^+3.1^_-1.3_x10^6^M_{sun}_ enclosed within the central ~160pc, and dynamical mass-to-light ratio 1913^+2234^_-950_M_{sun}_/L_{nu},{sun}_. For Gru 1 we estimate a mean velocity of -140.5^+2.4^_-1.6_km/s and a mean metallicity of [Fe/H]=-1.42^+0.55^_-0.42_ but our sample does not resolve Gru 1's velocity dispersion. The radial coordinates of Tuc 2 and Gru 1 in Galactic phase space suggest that their orbits are among the most energetic within a distance of <~300pc. Moreover, their proximity to each other in this space arises naturally if both objects are trailing the Large Magellanic Cloud.

Keywords
  1. galaxies
  2. spectroscopy
  3. metallicity
  4. infrared-photometry
  5. visible-astronomy
  6. Wide-band photometry
Bibliographic source Bibcode
2016ApJ...819...53W
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/819/53
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJ/819/53
Document Object Identifer DOI
doi:10.26093/cds/vizier.18190053

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/819/53
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/819/53
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/819/53
IVOA Table Access TAP
http://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/819/53/table1?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/819/53/table1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/819/53/table1?

History

2016-06-17T14:39:31Z
Resource record created
2016-06-17T14:39:31Z
Created
2018-01-08T07:01:55Z
Updated

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr