Star cluster provides telltale signs of galactic wind

An international research team has used pulsar data from CSIRO’s Parkes telescope, one of the SKA pathfinders, to study the Milky Way’s magnetic field and find clues pointing to the galactic wind. The team’s results were published in Nature Astronomy.

The galactic magnetic field plays an important role in the evolution of our galaxy, but its behaviour is still poorly understood. Using pulsars located in a tight cluster of stars in our galaxy’s halo called 47 Tuc, the team discovered an unexpected strong magnetic field in the direction of the cluster that could be explained by an interaction with what’s called the galactic wind - a fast-moving wind of charged particles and gas thought to be coming from the supermassive black hole at the centre of our galaxy. The existence of this galactic wind has never been proven before.

Galactic magnetic fields can influence star formation and help establish the presence of a flow of gas from the galactic disk to its surrounding halo. In the future, South Africa’s SKA precursor telescope MeerKAT, and the SKA itself, will provide even better measurements which could confirm the presence of the Galactic wind and investigate its properties, as well as having the capability to observe other similar clusters and corroborate the results.

Globular cluster 47 Tuc. The inset is a close-up of the cluster showing the detected magnetic field in a colour scale. The lines indicate the effect of the Galactic wind on the magnetic field.

Credit: ESO/VISTA VMC (background image); F. Abbate et al., Nature Astronomy (inset)

Source: Max Plank Institute for Radioastronomy