Rewinder adrian price-whelan 

Tidal disruption is simple 

t = 0 Price-Whelan et al. (2014) Rewinder 

Rewinder Price-Whelan et al. (2014) t = -1 evaluate likelihood 

Rewinder Price-Whelan et al. (2014) t = -2 evaluate likelihood 

Rewinder Price-Whelan et al. (2014) t = -3 

⌧ub K unbinding time leading/trailing tail M mass today any parametrization per star progenitor potential (l, b, d, µl, µb, vr) (l, b, d, µl, µb, vr) marginalize out WE’RE HOSED Rewinder Price-Whelan et al. (2014) 

−100 −50 0 50 X [kpc] −100 −50 0 X [kpc] x “Data”: Price-Whelan et al. (2014) 8 “RR Lyrae” stars Gaia velocity errors 2% distance errors + Progenitor, same errors 

8 RR Lyrae stars Gaia velocity errors 2% distance error Price-Whelan et al. (2014) 

Price-Whelan et al. (2014) 8 RR Lyrae stars 2% distance errors No proper motions 

Price-Whelan et al. (2014) Recover unobserved proper motion for stars 

Nparams / 6Nstars Good: Bad: - test particle orbits (no N-body) - arbitrary potentials - observational uncertainties / missing data - less sensitive to observational biases 

Next Marginalize true phase-space positions of the stars Marginal likelihood has fixed dimensionality set by potential params., progenitor params Price-Whelan et al. (in prep.)