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

5 pages, 2 figures, accepted for publications in MNRAS Letters

References in corpus (8)

• The Laniakea supercluster of galaxies
• The M31 Velocity Vector. II. Radial Orbit Towards the Milky Way and Implied Local Group Mass
• The Hubble flow around the Local Group
• The M31 Velocity Vector. I. Hubble Space Telescope Proper Motion Measurements
• M31 Transverse Velocity and Local Group Mass from Satellite Kinematics
• Constrained Local UniversE Simulations: A Local Group Factory
• Minimization of Biases in Galaxy Peculiar Velocity Catalogs
• The Transverse velocity of the Andromeda system, derived from the M31 satellite population

Cited by in corpus (8)

• The Local Group on FIRE: Dwarf galaxy populations across a suite of hydrodynamic simulations
• First Gaia Dynamics of the Andromeda System: DR2 Proper Motions, Orbits, and Rotation of M31 and M33
• Constraining the mass of the Local Group
• Tidally induced morphology of M33 in hydrodynamical simulations of its recent interaction with M31
• How does the grouping scheme affect the Wiener Filter reconstruction of the local Universe?
• Toward an Optimal Sampling of Peculiar Velocity Surveys For Wiener Filter Reconstructions
• Formation of Andromeda II via a gas-rich major merger and an interaction with M31
• Estimation of the masses in the Local Group by Gradient Boosted Decision Trees