Exciting news: today we have a new paper out in Nature Astronomy, titled “Andromeda’s asymmetric satellite system as a challenge to cold dark matter cosmology”. It is led by Kosuke Jamie Kanehisa, a PhD student in my group, and we worked on it together with our AIP colleague Noam Libeskind.
Our study looks at the system of satellite galaxies around the Andromeda galaxy. The observed satellite galaxies are distributed in a highly asymmetric, lopsided manner towards the Milky Way. We test for the first time whether such a weird arrangement also happens for analogs to Andromeda in cosmological simulations and find that the observed system is in fact highly unexpected. This is on top of the existence of a plane of satellite galaxies around Andromeda, which in itself already challenged the cold dark matter standard model of cosmology.
In addition to the article itself, we also wrote a research briefing for Nature Astronomy, and have prepared a press release on the topic. Jamie even created a nice illustrative animation of the Andromeda Satellite galaxy system and its peculiar arrangement for this purpose.