Evidence for coupling between the Sagittarius dwarf galaxy and the Milky Way warp
arXiv:astro-ph/0301014 · doi:10.1086/368160
Abstract
Using recent determinations of the mass and orbit of Sagittarius, I calculate its orbital angular momentum. From the latest observational data, I also calculate the angular momentum of the Milky Way's warp. I find that both angular momenta are directed toward l=270, b=0, and have magnitude 2-8x10^12 M_Sun kpc km s^-1, where the range in both cases reflects uncertainty in the mass. The coincidence of the angular momenta is suggestive of a coupling between these systems. Direct gravitational torque of Sgr on the disk is ruled out as the coupling mechanism. Gravitational torque due to a wake in the halo and the impulsive deposition of momentum by a passage of Sgr through the disk are still both viable mechanisms pending better simulations to test their predictions on the observed Sgr-MW system.
11 pages, to appear in the February 1 issue of ApJL
References in corpus (2)
Cited by in corpus (33)
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