A dipole on the sky: predictions for hypervelocity stars from the Large Magellanic Cloud

We predict the distribution of hypervelocity stars (HVSs) ejected from the Large Magellanic Cloud (LMC), under the assumption that the dwarf galaxy hosts a central massive black hole (MBH). For the majority of stars ejected from the LMC, the orbital velocity of the LMC has contributed a significant...

Szczegółowa specyfikacja

Opis bibliograficzny
Główni autorzy: Boubert, D, Evans, N
Format: Journal article
Wydane: American Astronomical Society 2016
Opis
Streszczenie:We predict the distribution of hypervelocity stars (HVSs) ejected from the Large Magellanic Cloud (LMC), under the assumption that the dwarf galaxy hosts a central massive black hole (MBH). For the majority of stars ejected from the LMC, the orbital velocity of the LMC has contributed a significant fraction of their galactic rest-frame velocity, leading to a dipole density distribution on the sky. We quantify the dipole using spherical harmonic analysis and contrast with the monopole expected for HVSs ejected from the Galactic center (GC). There is a tendril in the density distribution that leads the LMC, which is coincident with the well-known and unexplained clustering of HVSs in the constellations of Leo and Sextans. Our model is falsifiable since it predicts that Gaia will reveal a large density of HVSs in the southern hemisphere.