Evidence for coupling between the Sagittarius dwarf galaxy and the Milky Way warp

被引:39
作者
Bailin, J [1 ]
机构
[1] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA
关键词
galaxies : individual (Sagittarius dSph); galaxies : interactions; Galaxy : disk; Galaxy : halo; Galaxy : kinematics and dynamics;
D O I
10.1086/368160
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
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 approximate to 270degrees, b = 0degrees and have magnitude (2-8) x 10(12) M. kpc 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 Sagittarius-Milky Way system.
引用
收藏
页码:L79 / L82
页数:4
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