A High-Resolution Spectrum of the Extremely Metal-rich Bulge G Dwarf OGLE-2006-BLG-265
Abstract
We present an R = 45,000 Keck spectrum of the microlensed Galactic bulge G dwarf OGLE-2006-BLG-265, which has high (~60) signal-to-noise ratio despite its short (15 minute) exposure time, because the source was magnified by A ~ 135. While it is very metal-rich ([Fe/H] = 0.56), the higher temperature of this star compared with the luminous red giants usually measured in the bulge gives its spectrum many unblended atomic lines. We measure the abundances of 17 elements, including the first abundances for S and Cu in a bulge star. The [a/Fe] ratios are subsolar, while the odd-Z elements are slightly supersolar, trends that are also seen in the more metal-rich stars in the bulge and the local Galactic disk. Because the star is a dwarf, the [O/Fe], [Na/Fe], and [Al/Fe] ratios cannot be attributed to internal mixing, as is sometimes claimed for giants. Similar high-resolution spectra could be obtained for about a dozen bulge dwarf stars per year by means of well-designed target-of-opportunity observations.
Additional Information
© 2007. The American Astronomical Society. Received 2006 August 30; accepted 2006 December 11; published 2007 January 9. We acknowledge support from Hubble Fellowship HST-HF-01158.01-A (NASA contract NAS-5-2655; A.G.-Y.); NSF AST-042758, NASA NNG04GL51G (A.G.); NASA HST-AR-10673 (NASA contract NAS5-26555; D.C.L.); NSF AST-0204908, NASA grant NAG5-12212, Polish MNiSW BST grant (A.U.); We recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.Attached Files
Published - JOHapjl07.pdf
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Additional details
- Eprint ID
- 12806
- Resolver ID
- CaltechAUTHORS:JOHapjl07
- HST-HF-01158.01-A
- NASA Hubble Fellowship
- NAS-5-2655
- NASA
- AST-042758
- NSF
- NNG04GL51G
- NASA
- HST-AR-10673
- NASA
- NAS5-26555
- NASA
- AST-0204908
- NSF
- NAG5-12212
- NASA
- Ministerstwo Nauki i Szkolnictwa Wyższego (MNiSW)
- Created
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2008-12-24Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field