%0 Generic %1 sawala2021sibelius %A Sawala, Till %A McAlpine, Stuart %A Jasche, Jens %A Lavaux, Guilhem %A Jenkins, Adrian %A Johansson, Peter H. %A Frenk, Carlos S. %D 2021 %K library %T The SIBELIUS Project: E Pluribus Unum %U http://arxiv.org/abs/2103.12073 %X We introduce "Simulations Beyond The Local Universe" (SIBELIUS) that connect the Local Group to its cosmic environment. We show that introducing hierarchical small-scale perturbations to a density field constrained on large scales by observations provides an efficient way to explore the sample space of Local Group analogues. From more than 60 000 simulations, we identify a hierarchy of Local Group characteristics emanating from different scales: the total mass, orientation, orbital energy and the angular momentum are largely determined by modes above $łambda$ = 1.6 comoving Mpc (cMpc) in the primordial density field. Smaller scale variations are mostly manifest as perturbations to the MW-M31 orbit, and we find that the observables commonly used to describe the Local Group -- the MW-M31 separation and radial velocity -- are transient and depend on specifying scales down to 0.2 cMpc in the primordial density field. We further find that the presence of M33/LMC analogues significantly affects the MW-M31 orbit and its sensitivity to small-scale perturbations. We construct initial conditions that lead to the formation of a Local Group whose primary observables precisely match the current observations.

@misc{sawala2021sibelius, abstract = {We introduce "Simulations Beyond The Local Universe" (SIBELIUS) that connect the Local Group to its cosmic environment. We show that introducing hierarchical small-scale perturbations to a density field constrained on large scales by observations provides an efficient way to explore the sample space of Local Group analogues. From more than 60 000 simulations, we identify a hierarchy of Local Group characteristics emanating from different scales: the total mass, orientation, orbital energy and the angular momentum are largely determined by modes above $\lambda$ = 1.6 comoving Mpc (cMpc) in the primordial density field. Smaller scale variations are mostly manifest as perturbations to the MW-M31 orbit, and we find that the observables commonly used to describe the Local Group -- the MW-M31 separation and radial velocity -- are transient and depend on specifying scales down to 0.2 cMpc in the primordial density field. We further find that the presence of M33/LMC analogues significantly affects the MW-M31 orbit and its sensitivity to small-scale perturbations. We construct initial conditions that lead to the formation of a Local Group whose primary observables precisely match the current observations.}, added-at = {2021-03-24T07:36:31.000+0100}, author = {Sawala, Till and McAlpine, Stuart and Jasche, Jens and Lavaux, Guilhem and Jenkins, Adrian and Johansson, Peter H. and Frenk, Carlos S.}, biburl = {https://www.bibsonomy.org/bibtex/24bb1eb8ef349ab0e01d0d95bf9061702/gpkulkarni}, description = {The SIBELIUS Project: E Pluribus Unum}, interhash = {8d49a867b196b01f0884323b11f325f3}, intrahash = {4bb1eb8ef349ab0e01d0d95bf9061702}, keywords = {library}, note = {cite arxiv:2103.12073Comment: 14 pages, 15 figures. Submitted to MNRAS, comments welcome!}, timestamp = {2021-03-24T07:36:31.000+0100}, title = {The SIBELIUS Project: E Pluribus Unum}, url = {http://arxiv.org/abs/2103.12073}, year = 2021 }