Orphan stream high-resolution spectroscopic study Virtual Observatory Resource

Authors
  1. Casey A.R.
  2. Keller S.C.
  3. Da Costa G.
  4. Frebel A.
  5. Maunder E.
  6. Published by
    CDS
Abstract

We present the first high-resolution spectroscopic study on the Orphan stream for five stream candidates, observed with the Magellan Inamori Kyocera Echelle spectrograph on the Magellan Clay telescope. The targets were selected from the low-resolution catalog of Casey et al. (2013ApJ...764...39C): three high-probability members, one medium, and one low-probability stream candidate were observed. Our analysis indicates that the low- and medium-probability targets are metal-rich field stars. The remaining three high-probability targets range over ~1 dex in metallicity, and are chemically distinct compared to the other two targets and all standard stars: low [{alpha}/Fe] abundance ratios are observed, and lower limits are ascertained for [Ba/Y], which sit well above the Milky Way trend. These chemical signatures demonstrate that the undiscovered parent system is unequivocally a dwarf spheroidal galaxy, consistent with dynamical constraints inferred from the stream width and arc. As such, we firmly exclude the proposed association between NGC 2419 and the Orphan stream. A wide range in metallicities adds to the similarities between the Orphan stream and Segue 1, although the low [{alpha}/Fe] abundance ratios in the Orphan stream are in tension with the high [{alpha}/Fe] values observed in Segue 1. Open questions remain before Segue 1 could possibly be claimed as the "parent" of the Orphan stream. The parent system could well remain undiscovered in the southern sky.

Keywords
  1. milky-way-galaxy
  2. halo-stars
  3. line-intensities
  4. chemical-abundances
Bibliographic source Bibcode
2014ApJ...784...19C
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/784/19
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJ/784/19
Document Object Identifer DOI
doi:10.26093/cds/vizier.17840019

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/784/19
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/784/19
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/784/19
IVOA Table Access TAP
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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/784/19/table1?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/784/19/table1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/784/19/table1?

History

2017-07-03T13:39:57Z
Resource record created
2017-07-03T13:39:57Z
Created
2017-09-04T08:00:33Z
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