J/ApJ/819/2 APOGEE kinematics. I. Galactic bulge overview (Ness+, 2016)
APOGEE kinematics.
I. Overview of the kinematics of the Galactic bulge as mapped by APOGEE.
Ness M., Zasowski G., Johnson J.A., Athanassoula E., Majewski S.R.,
Garcia Perez A.E., Bird J., Nidever D., Schneider D.P., Sobeck J.,
Frinchaboy P., Pan K., Bizyaev D., Oravetz D., Simmons A.
<Astrophys. J., 819, 2 (2016)>
=2016ApJ...819....2N 2016ApJ...819....2N (SIMBAD/NED BibCode)
ADC_Keywords: Abundances ; Spectroscopy ; Stars, distances ; Surveys
Keywords: stars: abundances; stars: fundamental parameters;
stars: kinematics and dynamics; surveys; techniques: spectroscopic
Abstract:
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 10000
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.
Description:
We use the APOGEE spectra (R=22500) from the SDSS-III Data Release 12
(DR12; Ahn et al. 2014ApJS..211...17A 2014ApJS..211...17A) for about 20000 stars toward
the Galactic bulge and surrounding disk. The APOGEE survey, part of
the SDSS-III project (Eisenstein et al. 2011AJ....142...72E 2011AJ....142...72E), operates
at the 2.5m telescope of the Apache Point Observatory.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 63 18820 Fit stellar parameters
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/A+A/587/A124 : Metal-poor stars towards the Galactic bulge (Koch+, 2016)
J/A+A/584/A46 : GIRAFFE Inner Bulge Survey (GIBS). II. (Gonzalez+, 2015)
J/ApJ/808/16 : The Cannon: new approach to determine abundances (Ness+, 2015)
J/ApJS/215/19 : APOKASC catalog of Kepler red giants (Pinsonneault+, 2014)
J/A+A/562/A66 : GIRAFFE Inner Bulge Survey (GIBS). I. (Zoccali+, 2014)
J/AJ/146/133 : Stellar parameters from SDSS-III APOGEE DR10 (Meszaros+, 2013)
J/A+A/546/A57 : Spectrosc. of 400 red giants in the Bulge (Uttenthaler+, 2012)
J/AJ/143/57 : New RVs from the spectrosc. survey BRAVA (II) (Kunder+, 2012)
J/A+A/534/A80 : Bulge clump giant abundances in Baade's window (Hill+, 2011)
J/ApJ/721/L28 : Red clump stars in Galactic Bulge from OGLE-III (Nataf+, 2010)
J/A+A/486/177 : Bulge field stars from FLAMES-GIRAFFE spectra (Zoccali+, 2008)
http://www.sdss3.org/ : SDSS-III home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS The 2MASS identifier (JHHMMSSss+DDMMSSs)
25- 30 F6.1 K Teff [3532/5591] Effective Temperature
32- 35 F4.1 [cm/s2] logg [-0.1/4.8] Log surface gravity
37- 41 F5.2 [Sun] [Fe/H] [-2.4/0.7] Metallicity, [Fe/H]
43- 47 F5.2 [Sun] [a/Fe] [-0.3/0.5] Metallicity, [α/Fe]
49- 51 F3.1 --- chi2 [0.3/6] The Cannon (Ness et al. 2015,
J/ApJ/808/16) fit reduced χ2
53- 56 F4.1 kpc Dist [0/35.2] Fit derived distance, Kiloparsecs
58- 63 F6.1 km/s Vgal [-396/332] Fit derived galactocentric velocity (1)
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Note (1): The galactocentric velocity has been determined using the VHELIO_AVG
velocity measurements provided by APOGEE (which are strictly barycentric
measurements, see Hotlzman et al. (2015AJ....150..148H 2015AJ....150..148H),
as per Ness et al. (2013MNRAS.432.2092N 2013MNRAS.432.2092N).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-May-2016