Bibcode
Ness, M.; Zasowski, G.; Johnson, J. A.; Athanassoula, E.; Majewski, S. R.; García Pérez, A. E.; Bird, J.; Nidever, D.; Schneider, Donald P.; Sobeck, J.; Frinchaboy, P.; Pan, Kaike; Bizyaev, Dmitry; Oravetz, Daniel; Simmons, Audrey
Bibliographical reference
The Astrophysical Journal, Volume 819, Issue 1, article id. 2, 16 pp. (2016).
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3
2016
Journal
Citations
62
Refereed citations
57
Description
We present the stellar kinematics across the Galactic bulge and into the
disk at positive longitudes from the SDSS-III APOGEE spectroscopic
survey of the Milky Way. APOGEE includes extensive coverage of the
stellar populations of the bulge along the midplane and near-plane
regions. From these data, we have produced kinematic maps of 10,000
stars across longitudes of 0° < l < 65°, and primarily
across latitudes of | b| < 5° in the bulge region. The APOGEE
data reveal that the bulge is cylindrically rotating across all
latitudes and is kinematically hottest at the very center of the bulge,
with the smallest gradients in both kinematic and chemical space inside
the innermost region (| l,b| ) < (5°, 5°). The results from
APOGEE show good agreement with data from other surveys at higher
latitudes and a remarkable similarity to the rotation and dispersion
maps of barred galaxies viewed edge-on. The thin bar that is reported to
be present in the inner disk within a narrow latitude range of | b|
< 2° appears to have a corresponding signature in [{Fe}/{{H}}]
and [α /{Fe}]. Stars with [{Fe}/{{H}}] >‑0.5 have
dispersion and rotation profiles that are similar to that of N-body
models of boxy/peanut bulges. There is a smooth kinematic transition
from the thin bar and boxy bulge (l,| b| ) < (15°, 12°) out
to the disk for stars with [{Fe}/{{H}}] >‑1.0, and the
chemodynamics across (l, b) suggests that the stars in the inner Galaxy
with [{Fe}/{{H}}] >‑1.0 originate in the disk.