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.
%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
}