Simulation 1 of the Jhelum stream after interacting with the Sgr dwarf spheroidal. The individual star particles from Jhelum are colour-coded according to the lookback time at which they became unbound. Panel a: shows the stream in ϕ₁-ϕ₂ frame, while (panels b) and (c) show the (non-reflex corrected) PM in the ϕ₁ and ϕ₂ directions respectively. Panel d: radial velocity, and Panel (e) the distance. The red datapoints correspond to the binned Jhelum data from Sect. 2.2, and the blue datapoints correspond to stars from Ji et al. (2020) that are likely members of the narrow component of Jhelum. The magenta triangle corresponds to Jhelum2_2, the datapoint which in our simulations marks the present-day location of the progenitor. The magenta dotted line shows the trajectory of the centre of mass of the Jhelum progenitor, and the grey dashed line shows the result from the MCMC best-fit with σ_nuis = 6.7 km s⁻¹ from Sect. 3.1. Panel a: clear secondary and tertiary components, which are also apparent in the other panels. These additional components are made up of particles that were released early on in the formation of the stream.