CONSTRAINTS ON THE SHAPE OF THE MILKY WAY DARK MATTER HALO FROM THE SAGITTARIUS STREAM

Journal Article · Sat Aug 10 04:00:00 EDT 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/773/1/L4· OSTI ID:22140252

Vera-Ciro, Carlos ^[1]; Helmi, Amina ^[2]

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1. Department of Astronomy, University of Wisconsin, 2535 Sterling Hall, 475 N. Charter Street, Madison, WI 53076 (United States)
2. Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, 9700 AV Groningen (Netherlands)

We propose a new model for the dark matter halo of the Milky Way that fits the properties of the stellar stream associated with the Sagittarius dwarf galaxy. Our dark halo is oblate with q{sub z} = 0.9 for r {approx}< 10 kpc, and can be made to follow the Law and Majewski model at larger radii. However, we find that the dynamical perturbations induced by the Large Magellanic Cloud on the orbit of Sgr cannot be neglected when modeling its streams. When taken into account, this leads us to constrain the Galaxy's outer halo shape to have minor-to-major axis ratio >(c/a){sub {Phi}} = 0.8 and intermediate-to-major axis ratio (b/a){sub {Phi}} = 0.9, in good agreement with cosmological expectations.

• OSTI ID: 22140252
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 773; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DISTURBANCES
INTERACTIONS
LIMITING VALUES
MAGELLANIC CLOUDS
MILKY WAY
NONLUMINOUS MATTER
ORBITS
PERTURBATION THEORY
SIMULATION
STREAMS