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The halo of the Milky Way galaxy hosts multiple dynamically coherentsubstructures known as stellar streams that are remnants of tidally disruptedsystems such as globular clusters (GCs) and dwarf galaxies (DGs). A particularcase is that of the Jhelum stream, which is known for its complex morphology.Using the available data from Gaia DR3, we extracted a region on the sky thatcontains Jhelum. We then applied the novel Locally Aligned Ant Technique (LAAT)on the position and proper motion space of stars belonging to the selectedregion to highlight the stars that are closely aligned with a local manifold inthe data and the stars belonging to regions of high local density. We find thatthe overdensity representing the stream in proper motion space is composed oftwo components, and show the correspondence of these two signals to thepreviously reported narrow and broad spatial components of Jhelum. We made useof the radial velocity measurements provided by the $S^5$ survey to confirm,for the first time, a separation between the two components in radial velocity.We show that the narrow and broad components have velocity dispersions of$4.84^{+1.23}_{-0.79}$~km/s and $19.49^{+2.19}_{-1.84}$~km/s, and metallicitydispersions of $0.15^{+0.18}_{-0.10}$ and $0.34^{+0.13}_{-0.09}$, respectively.These measurements, and the difference in component widths, could be explainedwith a scenario where Jhelum is the remnant of a GC embedded within a DG thatwere accreted onto the Milky Way during their infall. Although the propertiesof Jhelum can be explained with this merger scenario, other progenitors of thenarrow component remain possible such as a nuclear star cluster or a DG. Torule these possibilities out, we would need more observational data of memberstars of the stream. Our analysis highlights the importance of the internalstructure of streams with regards to their formation history.

Swarming in stellar streams: Unveiling the structure of the Jhelum stream with ant colony-inspired computation