Advanced

The EMBLA survey - metal-poor stars in the Galactic bulge

Howes, L.~M. LU ; Asplund, M.; Keller, S.~C.; Casey, A.~R.; Yong, D.; Lind, K.; Frebel, A.; Hays, A.; Alves-Brito, A. and Bessell, M.~S., et al. (2016) In Monthly Notices of the Royal Astronomical Society 460(1). p.884-901
Abstract
Cosmological models predict the oldest stars in the Galaxy should be found closest to the centre of the potential well, in the bulge. The Extremely Metal-poor BuLge stars with AAOmega survey (EMBLA) successfully searched for these old, metal-poor stars by making use of the distinctive SkyMapper photometric filters to discover candidate metal-poor stars in the bulge. Their metal-poor nature was then confirmed using the AAOmega spectrograph on the Anglo-Australian Telescope. Here we present an abundance analysis of 10 bulge stars with −2.8 < [Fe/H] < −1.7 from MIKE/Magellan observations, in total determining the abundances of 22 elements. Combining these results with our previous high-resolution data taken as part of the Gaia-ESO... (More)
Cosmological models predict the oldest stars in the Galaxy should be found closest to the centre of the potential well, in the bulge. The Extremely Metal-poor BuLge stars with AAOmega survey (EMBLA) successfully searched for these old, metal-poor stars by making use of the distinctive SkyMapper photometric filters to discover candidate metal-poor stars in the bulge. Their metal-poor nature was then confirmed using the AAOmega spectrograph on the Anglo-Australian Telescope. Here we present an abundance analysis of 10 bulge stars with −2.8 < [Fe/H] < −1.7 from MIKE/Magellan observations, in total determining the abundances of 22 elements. Combining these results with our previous high-resolution data taken as part of the Gaia-ESO Survey, we have started to put together a picture of the chemical and kinematic nature of the most metal-poor stars in the bulge. The currently available kinematic data are consistent with the stars belonging to the bulge, although more accurate measurements are needed to constrain the stars’ orbits. The chemistry of these bulge stars deviates from that found in halo stars of the same metallicity. Two notable differences are the absence of carbon-enhanced metal-poor bulge stars, and the α element abundances exhibit a large intrinsic scatter and include stars which are underabundant in these typically enhanced elements. (Less)
Please use this url to cite or link to this publication:
author
, et al. (More)
(Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
stars: abundances, stars: Population II, Galaxy: bulge, Galaxy: evolution
in
Monthly Notices of the Royal Astronomical Society
volume
460
issue
1
pages
18 pages
publisher
Wiley-Blackwell
external identifiers
  • scopus:84979082317
  • wos:000379835200059
ISSN
1365-2966
DOI
10.1093/mnras/stw1004
language
English
LU publication?
yes
id
d31d4129-9c5a-4002-a891-f97fb77d06e9
date added to LUP
2016-08-17 14:05:53
date last changed
2017-06-28 14:21:40
@article{d31d4129-9c5a-4002-a891-f97fb77d06e9,
  abstract     = {Cosmological models predict the oldest stars in the Galaxy should be found closest to the centre of the potential well, in the bulge. The Extremely Metal-poor BuLge stars with AAOmega survey (EMBLA) successfully searched for these old, metal-poor stars by making use of the distinctive SkyMapper photometric filters to discover candidate metal-poor stars in the bulge. Their metal-poor nature was then confirmed using the AAOmega spectrograph on the Anglo-Australian Telescope. Here we present an abundance analysis of 10 bulge stars with −2.8 &lt; [Fe/H] &lt; −1.7 from MIKE/Magellan observations, in total determining the abundances of 22 elements. Combining these results with our previous high-resolution data taken as part of the Gaia-ESO Survey, we have started to put together a picture of the chemical and kinematic nature of the most metal-poor stars in the bulge. The currently available kinematic data are consistent with the stars belonging to the bulge, although more accurate measurements are needed to constrain the stars’ orbits. The chemistry of these bulge stars deviates from that found in halo stars of the same metallicity. Two notable differences are the absence of carbon-enhanced metal-poor bulge stars, and the α element abundances exhibit a large intrinsic scatter and include stars which are underabundant in these typically enhanced elements.},
  author       = {Howes, L.~M. and Asplund, M. and Keller, S.~C. and Casey, A.~R. and Yong, D. and Lind, K. and Frebel, A. and Hays, A. and Alves-Brito, A. and Bessell, M.~S. and Casagrande, L. and Marino, A.~F. and Nataf, D.~M. and Owen, C.~I. and Da Costa, G.~S. and Schmidt, B.~P. and Tisserand, P.},
  issn         = {1365-2966},
  keyword      = {stars: abundances, stars: Population II, Galaxy: bulge, Galaxy: evolution},
  language     = {eng},
  month        = {07},
  number       = {1},
  pages        = {884--901},
  publisher    = {Wiley-Blackwell},
  series       = {Monthly Notices of the Royal Astronomical Society},
  title        = {The EMBLA survey - metal-poor stars in the Galactic bulge},
  url          = {http://dx.doi.org/10.1093/mnras/stw1004},
  volume       = {460},
  year         = {2016},
}