Modelling the Tucana III stream - a close passage with the LMC
Abstract
We present results of the first dynamical stream fits to the recently discovered Tucana III stream. These fits assume a fixed Milky Way potential and give proper motion predictions, which can be tested with the upcoming Gaia Data Release 2. These fits reveal that Tucana III is on an eccentric orbit around the Milky Way and, more interestingly, that Tucana III passed within 15 kpc of the Large Magellanic Cloud (LMC) approximately 75 Myr ago. Given this close passage, we fit the Tucana III stream in the combined presence of the Milky Way and the LMC. We find that the predicted proper motions depend on the assumed mass of the LMC and that the LMC can induce a substantial proper motion perpendicular to the stream track. A detection of this misalignment will directly probe the extent of the LMC's influence on our Galaxy, and has implications for nearly all methods which attempt to constraint the Milky Way potential. Such a measurement will be possible with the upcoming Gaia DR2, allowing for a measurement of the LMC's mass.
Keywords
Cite
@article{arxiv.1804.07762,
title = {Modelling the Tucana III stream - a close passage with the LMC},
author = {D. Erkal and T. S. Li and S. E. Koposov and V. Belokurov and E. Balbinot and K. Bechtol and B. Buncher and A. Drlica-Wagner and K. Kuehn and J. L. Marshall and C. E. Martinez-Vazquez and A. B. Pace and N. Shipp and J. D. Simon and K. M. Stringer and A. K. Vivas and R. H. Wechsler and B. Yanny and F. B. Abdalla and S. Allam and J. Annis and S. Avila and E. Bertin and D. Brooks and E. Buckley-Geer and D. L. Burke and A. Carnero Rosell and M. Carrasco Kind and J. Carretero and C. B. D'Andrea and L. N. da Costa and C. Davis and J. De Vicente and P. Doel and T. F. Eifler and A. E. Evrard and B. Flaugher and J. Frieman and J. García-Bellido and E. Gaztanaga and D. W. Gerdes and D. Gruen and R. A. Gruendl and J. Gschwend and G. Gutierrez and W. G. Hartley and D. L. Hollowood and K. Honscheid and D. J. James and E. Krause and M. A. G. Maia and M. March and F. Menanteau and R. Miquel and R. L. C. Ogando and A. A. Plazas and E. Sanchez and B. Santiago and V. Scarpine and R. Schindler and I. Sevilla-Noarbe and M. Smith and R. C. Smith and M. Soares-Santos and F. Sobreira and E. Suchyta and M. E. C. Swanson and G. Tarle and D. L. Tucker and A. R. Walker},
journal= {arXiv preprint arXiv:1804.07762},
year = {2018}
}
Comments
13 pages, 8 figures, submitted to MNRAS. Comments welcome! See also Li et al. "The First Tidally Disrupted Ultra-Faint Dwarf Galaxy? -- Spectroscopic Analysis of the Tucana III Stream" on today's astro-ph