Bibcode
Hayden, M. R.; Holtzman, J. A.; Meszaros, Sz.; Beers, T. C.; Robin, A.; Bovy, J.; Skrutskie, M. F.; Sellgren, K.; Wilson, J. C.; Zasowski, G.; Nidever, D.; Perez, A.; Bizyaev, D.; Cunha, K. M.; Shetrone, M. D.; Allende-Prieto, C.; Schiavon, R. P.; Hearty, F. R.; Majewski, S. R.; Frinchaboy, P. M.; Smith, V. V.; Johnson, J.
Referencia bibliográfica
American Astronomical Society, AAS Meeting #221, #254.14
Advertised on:
1
2013
Número de citas
0
Número de citas referidas
0
Descripción
We present initial abundance gradients in the Milky Way as determined
from high-resolution (R > 20,000) spectra of red giant stars. Our
observations were taken with the SDSS-III APO Galactic Evolution
Experiment (APOGEE) and have a S/N of at least 100. APOGEE is able to
sample a large range of Galactocentric radii (RGC) including
the bulge and inner disk regions of the galaxy by working in the
near-IR. From a sample of nearly 30,000 stars taken during the first
year of APOGEE operation, we estimate distances using
spectroscopically-derived surface gravities combined with extinction
estimates from near- and mid-IR photometry. This sample includes stars
with 0 < RGC < 20 kpc, and is constrained to a range of
heights about the plane, Z, from 0 to 2 kpc. We determine radial
abundance gradients for subsamples that include different heights about
the plane and different [α/Fe] ratios. We find that the radial
abundance gradient is steeper in the plane than above it for stars with
near-solar [α/Fe], and mostly flat for stars with higher
[α/Fe] at all Z.