Astronomy and Astrophysics, volume 577A, 1-1 (2015/5-1)
Why the Milky Way's bulge is not only a bar formed from a cold thin disk.
DI MATTEO P., GOMEZ A., HAYWOOD M., COMBES F., LEHNERT M.D., NESS M., SNAITH O.N., KATZ D. and SEMELIN B.
Abstract (from CDS):
By analyzing an N-body simulation of a bulge formed simply via a bar instability mechanism operating on a kinematically cold stellar disk, and by comparing the results of this analysis with the structural and kinematic properties of the main stellar populations of the Milky Way bulge, we conclude that the bulge of our Galaxy is not a pure stellar bar formed from a pre-existing thin stellar disk, as some studies have recently suggested. On the basis of several arguments emphasized in this paper, we propose that the bulge population that, in the Milky Way, is observed to not be part of the peanut structure corresponds to the old Galactic thick disk, thus implying that the Milky Way is a pure thin+thick disk galaxy, with only a possible limited contribution by a classical bulge.
(Ref) Object type as listed in the reference "Ref"
(acronym) Object type linked to the acronym according to the original reference
() Anterior to 2007, before we can link the objet type to a reference, or given by the CDS team in some particular cases
Other object types:
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
ra dec : right ascension and declination (unit and frame defined according to your Output Options)
Grey values are increasing the original precision due to the computation of frame transformations
(wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
[error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
position angle (in degrees North celestial pole to East)