Are galaxies spinning in alignment with the cosmic web?

A new paper by the MIGHTEE-HI team reveals the connection between the direction of spin of galaxies and underlying large scale web of structure fund in the universe.

Using a sample of 77 galaxies that are also known from other observations, the scientists calculated the axis around which the galaxies are spinning. If the background intergalactic distribution of matter (ordinary or dark), known as the cosmic web, and the direction of the axis of rotation of the galaxies show alignment, this adds to the evidence that the environment of galaxies plays an important role in their dynamics and in their evolution.

Analysing galaxies using MeerKAT data collected for the MIGHTEE project, the astronomers found evidence that the closer the galaxies are to the centre of filaments of large scale structure, the more they are aligned with those filaments. They also fund that the more the galaxies contain stars in comparison with hydrogen gas, the more they are aligned.

There is still much to be determined about galaxies and the influence of their intergalactic environment, but there is definitely growing evidence that galaxies are not evolving in isolation.

Galaxies, often referred to as islands of stars and gas in the cosmos, may not be as insular as previously assumed. This is an important step forward in the understanding of how galaxies come to be and come to look the way they are.

MIGHTEE-HI: The relation between the HI gas in galaxies and the cosmic web, Madalina N. TudoracheM. J. JarvisI. HeywoodA. A. PonomarevaN. MaddoxB. S. FrankN. J. AdamsR. A. A. BowlerI. H. WhittamM. BaesH. PanS. H. A. RajohnsonF. SinigagliaK. Spekkens, accepted for publication in MNRAS, arXiv:2204.03041

Image: Cosmic Web by Manasa Shastry