When a Bar Tricks the Eye: How Streaming Gas Motions Imitate a Bulge in the Milky Way
Junichi Baba’s study shows that gas motions in the Milky Way’s inner regions are strongly influenced by the central bar, creating non-circular streaming that mimics a massive bulge. Using simulations, he demonstrates that the steep rise in the inner rotation curve can be explained without extra mass, cautioning against overestimating the Galaxy’s central mass from gas-based methods alone.
Spinning Up the Galaxy: How the Milky Way’s Bar Transfers Motion to Its Bulge and Halo
Using Gaia data and simulations, Zhuohan Li et al. identified a rotating group of stars in the Milky Way's bulge and halo. Their findings show that the central bar, slowing down over time, transfers angular momentum to these stars through resonance trapping. This process explains the unexpected rotation in regions once thought to be mostly static.
Stellar Archaeology Disrupted: How the Milky Way’s Bar Smears Out Substructure
This study shows that the Milky Way’s rotating bar disrupts the orbits of stars, dispersing ancient substructures like globular clusters and stellar streams in integral of motion space. Traditional search methods may miss these smeared-out features. Instead, the authors suggest using the Jacobi integral and chemical properties, which better preserve the signatures of disrupted structures.