Bibcode
Schultheis, M.; Cunha, K.; Zasowski, G.; García Pérez, A. E.; Sellgren, K.; Smith, V.; García-Hernández, D. A.; Zamora, O.; Fritz, T. K.; Anders, F.; Allende Prieto, C.; Bizyaev, D.; Kinemuchi, K.; Pan, K.; Malanushenko, E.; Malanushenko, V.; Shetrone, M. D.
Bibliographical reference
Astronomy and Astrophysics, Volume 584, id.A45, 5 pp.
Advertised on:
12
2015
Journal
Citations
26
Refereed citations
23
Description
The inner Galactic bulge has, until recently, been avoided in chemical
evolution studies because of extreme extinction and stellar crowding.
Large, near-IR spectroscopic surveys, such as the Apache Point
Observatory Galactic Evolution Experiment (APOGEE), for the first time
allow the measurement of metallicities in the inner region of our
Galaxy. We study metallicities of 33 K/M giants situated in the Galactic
center region from observations obtained with the APOGEE survey. We
selected K/M giants with reliable stellar parameters from the
APOGEE/ASPCAP pipeline. Distances, interstellar extinction values, and
radial velocities were checked to confirm that these stars are indeed
situated in the inner Galactic bulge. We find a metal-rich population
centered at [M/H] = +0.4 dex, in agreement with earlier studies of other
bulge regions, but we also discovered a peak at low metallicity around
[M/H] = -1.0 dex. This finding suggests the presence of a metal-poor
population, which has not previously been detected in the central
region. Our results indicate a dominant metal-rich population with a
metal-poor component that is enhanced in the α-elements. This
metal-poor population may be associated with the classical bulge and a
fast formation scenario.
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