Physics of galactic colliders: high speed satellites in LCDM vs MONDian cosmology

Claudio Llinares, HongSheng Zhao, Alexander Knebe

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


The statistics of high speed satellite galaxies, as reported in the recent literature, can be a powerful diagnosis of the depth of the potential well of the host halo, and hence discriminate between competing gravitational theories. Naively one expects that high speed satellites are more common in Modified Newtonian Dynamics (MOND) than in cold dark matter (CDM) since an isolated MONDian system has an infinite potential well, while CDM halos have finite potential wells. In this \textit{Letter} we report on an initial test of this hypothesis in the context of the first generation of cosmological simulations utilising a rigorous MONDian Poisson solver. We find that such high speed encounters are approximately a factor of four more common in MOND than in the concordance $\Lambda$CDM model of cosmic structure formation.
Original languageUndefined/Unknown
Pages (from-to)L145-L148
JournalAstrophysical Journal
Issue number2
Publication statusPublished - 20 Apr 2009

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