Milky Way Mass and Potential Recovery
Using Tidal Streams in a Realistic Halo
Ana
1
arXiv:1406.6063
Bonaca, Marla Geha, Andreas Kuepper, Juerg Diemand, Kathryn Johnston, David Hogg
Streams abound in the Milky Way halo
2
Gravitational potential recovery usually assumes a smooth and static analytic potential
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Sample of 256 streams created in a:
Realistic potential
Via Lactea II
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.... but in reality it is clumpy and evolving.
Mass estimates using realistic streams are dispersed and biased.
5
analytic streams
realistic streams
NFW
potential
Mass residual (%)
Logarithmic
potential
Number of streams
truth
Number of streams
Analytic potential
Logarithmic/NFW
progenitor
Bonaca+(2012)
4
Yale
leading tail
Distant streams = more
accurate mass estimates.
NFW
potential
trailing tail
ol
de
rp
ar
Mass residual (%)
Mass residual (%)
Pericenter distance (kpc)
Assuming an analytic potential form biases mass measurement of a realistic halo on the order of 5 - 20 %.
younger part
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