The tangential velocity of M31: CLUES from constrained simulations
Abstract
Determining the precise value of the tangential component of the velocity of M31 is a non trivial astrophysical issue, that relies on complicated modeling. This has recently lead to con- flicting estimates, obtained by several groups that used different methodologies and assump- tions. This letter addresses the issue by computing a Bayesian posterior distribution function of this quantity, in order to measure the compatibility of those estimates with LambdaCDM. This is achieved using an ensemble of local group (LG) look-alikes collected from a set of Con- strained Simulations (CSs) of the local Universe, and a standard unconstrained LambdaCDM. The latter allows us to build a control sample of LG-like pairs and to single out the influence of the environment in our results. We find that neither estimate is at odds with LambdaCDM; how- ever, whereas CSs favour higher values of vtan , the reverse is true for estimates based on LG samples gathered from unconstrained simulations, overlooking the environmental element
Keywords
Cite
@article{arxiv.1603.09498,
title = {The tangential velocity of M31: CLUES from constrained simulations},
author = {Edoardo Carlesi and Yehuda Hoffman and Jenny G. Sorce and Stefan Gottloeber and Gustavo Yepes and Helene Courtois and R. Brent Tully},
journal= {arXiv preprint arXiv:1603.09498},
year = {2017}
}
Comments
5 pages, 2 figures, accepted for publications in MNRAS Letters