Reinforcing the link between the double red clump and the X-shaped bulge of the Milky Way

The finding of a double red clump in the luminosity function of the Milky Way bulge has been interpreted as evidence for an X-shaped structure. Recently, an alternative explanation has been suggested, where the double red clump is an effect of multiple stellar populations in a classical spheroid. In...

Full description

Saved in:
Bibliographic Details
Published in:Astronomy and astrophysics (Berlin) 2015-11, Vol.583, p.L5
Main Authors: Gonzalez, O. A., Zoccali, M., Debattista, V. P., Alonso-García, J., Valenti, E., Minniti, D.
Format: Article
Language:English
Subjects:
Assessments
Astronomy
Clumps
Galaxy: bulge
Galaxy: structure
Latitude
Line of sight
Luminosity
Searching
Spheroids
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The finding of a double red clump in the luminosity function of the Milky Way bulge has been interpreted as evidence for an X-shaped structure. Recently, an alternative explanation has been suggested, where the double red clump is an effect of multiple stellar populations in a classical spheroid. In this Letter we provide an observational assessment of this scenario and show that it is not consistent with the behaviour of the red clump across different lines of sight, particularly at high distances from the Galactic plane. Instead, we confirm that the shape of the red clump magnitude distribution closely follows the distance distribution expected for an X-shaped bulge at critical Galactic latitudes. We also emphasize some key observational properties of the bulge red clump that should not be neglected in the search for alternative scenarios.
ISSN:0004-6361
1432-0746
DOI:10.1051/0004-6361/201527434