Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Home
Search
Quick Search
Advanced
Fulltext
Browse
Collections
Persons
My eDoc
Session History
Login
Name:
Password:
Documentation
Help
Support Wiki
Direct access to
document ID:


          Institute: MPI für Astronomie     Collection: Publikationen_mpia     Display Documents



ID: 693689.0, MPI für Astronomie / Publikationen_mpia
Does the Sagittarius stream constrain the Milky Way halo to be triaxial?
Authors:Ibata, R.; Lewis, G. F.; Martin, N. F.; Bellazzini, M.; Correnti, M.
Date of Publication (YYYY-MM-DD):2013
Title of Journal:The Astrophysical Journal Letters
Volume:765
Issue / Number:1
Start Page:id. L15 (5 pp)
Audience:Not Specified
Abstract / Description:Recent analyses of the stellar stream of the Sagittarius dwarf galaxy have suggested that the kinematics and three-dimensional location of the M-giant stars in this structure constrain the dark matter halo of our Galaxy to possess a triaxial shape that is extremely flattened, being essentially an oblate ellipsoid oriented perpendicular to the Galactic disk. Using a new stream-fitting algorithm, based on a Markov Chain Monte Carlo procedure, we investigate whether this claim remains valid if we allow the density profile of the Milky Way halo greater freedom. We find stream solutions that fit the leading and trailing arms of this structure even in a spherical halo, although this would need a rising Galactic rotation curve at large Galactocentric radius. However, the required rotation curve is not ruled out by current constraints. It appears therefore that for the Milky Way, halo triaxiality, despite its strong theoretical motivation, is not required to explain the Sagittarius stream. This degeneracy between triaxiality and the halo density profile suggests that, in future endeavors to model this structure, it will be advantageous to relax the strict analytic density profiles that have been used to date.
Free Keywords:dark matter; galaxies: dwarf; Galaxy: halo
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für Astronomie
Identifiers:ISSN:0004-637X
URL:http://cdsads.u-strasbg.fr/abs/2013ApJ...765L..15I
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.