Using the multi-object adaptive optics demonstrator RAVEN to observe metal-poor stars in and towards the Galactic Centre
(2017) In Monthly Notices of the Royal Astronomical Society 465(3). p.3536-3557- Abstract
The chemical abundances for five metal-poor stars in and towards the Galactic bulge have been determined from the H-band infrared spectroscopy taken with the RAVEN multi-object adaptive optics science demonstrator and the Infrared Camera and Spectrograph at the Subaru 8.2-m telescope. Three of these stars are in the Galactic bulge and have metallicities between -2.1<[Fe/H] < -1.5, and high [α/Fe]~+0.3, typical of Galactic disc and bulge stars in this metallicity range; [Al/Fe] and [N/Fe] are also high, whereas [C/Fe] < +0.3. An examination of their orbits suggests that two of these stars may be confined to the Galactic bulge and one is a halo trespasser, though proper motion values used to calculate orbits are quite uncertain.... (More)
The chemical abundances for five metal-poor stars in and towards the Galactic bulge have been determined from the H-band infrared spectroscopy taken with the RAVEN multi-object adaptive optics science demonstrator and the Infrared Camera and Spectrograph at the Subaru 8.2-m telescope. Three of these stars are in the Galactic bulge and have metallicities between -2.1<[Fe/H] < -1.5, and high [α/Fe]~+0.3, typical of Galactic disc and bulge stars in this metallicity range; [Al/Fe] and [N/Fe] are also high, whereas [C/Fe] < +0.3. An examination of their orbits suggests that two of these stars may be confined to the Galactic bulge and one is a halo trespasser, though proper motion values used to calculate orbits are quite uncertain. An additional two stars in the globular cluster M22 show [Fe/H] values consistent to within 1σ, although one of these two stars has [Fe/H] = -2.01 ± 0.09, which is on the low end for this cluster. The [α/Fe] and [Ni/Fe] values differ by 2σ, with the most metal-poor star showing significantly higher values for these elements. M22 is known to show element abundance variations, consistent with a multipopulation scenario though our results cannot discriminate this clearly given our abundance uncertainties. This is the first science demonstration of multiobject adaptive optics with high-resolution infrared spectroscopy, and we also discuss the feasibility of this technique for use in the upcoming era of 30-m class telescope facilities.
(Less)
- author
- organization
- publishing date
- 2017-03
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Galaxy: centre, Globular clusters: individual: M22, Instrumentation: adaptive optics, Stars: abundances, Techniques: spectroscopic
- in
- Monthly Notices of the Royal Astronomical Society
- volume
- 465
- issue
- 3
- pages
- 22 pages
- publisher
- Oxford University Press
- external identifiers
-
- scopus:85014705542
- ISSN
- 0035-8711
- DOI
- 10.1093/mnras/stw2865
- language
- English
- LU publication?
- yes
- id
- 0aa77ffc-82eb-4c0c-aee4-148894198cd5
- date added to LUP
- 2022-04-04 11:12:36
- date last changed
- 2024-04-07 06:18:53
@article{0aa77ffc-82eb-4c0c-aee4-148894198cd5, abstract = {{<p>The chemical abundances for five metal-poor stars in and towards the Galactic bulge have been determined from the H-band infrared spectroscopy taken with the RAVEN multi-object adaptive optics science demonstrator and the Infrared Camera and Spectrograph at the Subaru 8.2-m telescope. Three of these stars are in the Galactic bulge and have metallicities between -2.1<[Fe/H] < -1.5, and high [α/Fe]~+0.3, typical of Galactic disc and bulge stars in this metallicity range; [Al/Fe] and [N/Fe] are also high, whereas [C/Fe] < +0.3. An examination of their orbits suggests that two of these stars may be confined to the Galactic bulge and one is a halo trespasser, though proper motion values used to calculate orbits are quite uncertain. An additional two stars in the globular cluster M22 show [Fe/H] values consistent to within 1σ, although one of these two stars has [Fe/H] = -2.01 ± 0.09, which is on the low end for this cluster. The [α/Fe] and [Ni/Fe] values differ by 2σ, with the most metal-poor star showing significantly higher values for these elements. M22 is known to show element abundance variations, consistent with a multipopulation scenario though our results cannot discriminate this clearly given our abundance uncertainties. This is the first science demonstration of multiobject adaptive optics with high-resolution infrared spectroscopy, and we also discuss the feasibility of this technique for use in the upcoming era of 30-m class telescope facilities.</p>}}, author = {{Lamb, M. and Venn, K. and Andersen, D. and Oya, S. and Shetrone, M. and Fattahi, A. and Howes, L. and Asplund, M. and Lardière, O. and Akiyama, M. and Ono, Y. and Terada, H. and Hayano, Y. and Suzuki, G. and Blain, C. and Jackson, K. and Correia, C. and Youakim, K. and Bradley, C.}}, issn = {{0035-8711}}, keywords = {{Galaxy: centre; Globular clusters: individual: M22; Instrumentation: adaptive optics; Stars: abundances; Techniques: spectroscopic}}, language = {{eng}}, number = {{3}}, pages = {{3536--3557}}, publisher = {{Oxford University Press}}, series = {{Monthly Notices of the Royal Astronomical Society}}, title = {{Using the multi-object adaptive optics demonstrator RAVEN to observe metal-poor stars in and towards the Galactic Centre}}, url = {{http://dx.doi.org/10.1093/mnras/stw2865}}, doi = {{10.1093/mnras/stw2865}}, volume = {{465}}, year = {{2017}}, }