Speaker
Description
Stellar streams are created when globular clusters or dwarf galaxies tidally disrupt in the gravitational potential of their host galaxy. These streams therefore offer a great probe to this galactic potential. Current observations show a multitude of Milky Way stellar streams to have substructure in the form of 'spurs', 'gaps' and even multiple components. These can originate from interactions of the stream with dark matter subhalos, which could probe the nature of dark matter. I'll talk about the specific case of the Jhelum stream, which shows multiple components after a close interaction with the Sagittarius Dwarf Galaxy, which means we should take the classical satellites into account when modelling stellar streams to infer information about the Milky Way potential.
Another recent observation (Dodd et al 2022a) shows that the Helmi Streams seem to orbit near one or multiple resonances. This results in substructure in angular momentum space. To explain the persistence of this substructure, one seems to need a prolate dark matter halo in the region where the Helmi streams orbit. If there is some time left, I'll talk about this substructure when considered in the context of an alternative theory of gravity called MOND (Modified Newtonian Dynamics). I'll introduce my simple MOND models of the Milky Way and discuss their ability to sustain this Helmi Streams substructure.
| Do you plan to attend the symposium in-person or virtually? | in-person |
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