A MeerKAT look at the polarization of 47 Tucanae pulsars: magnetic field implications

We present the polarization profiles of 22 pulsars in the globular cluster 47 Tucanae using observations from the MeerKAT radio telescope at UHF band (544-1088 MHz) and report precise values of dispersion measure (DM) and rotation measure (RM). We use these measurements to investigate the presence of turbulence in electron density and magnetic fields. The structure function of DM shows a break at similar to 30 arcsec (similar to 0.6 pc at the distance of 47 Tucanae) that suggests the presence of turbulence in the gas in the cluster driven by the motion of wind-shedding stars. On the other hand, the structure function of RM does not show evidence of a break. This non-detection could be explained either by the limited number of pulsars or by the effects of the intervening gas in the Galaxy along the line of sight. Future pulsar discoveries in the cluster could help confirm the presence and localize the turbulence.

Automated summary

We studied the polarization profiles of 22 pulsars in the globular cluster 47 Tucanae using MeerKAT radio telescope and reported precise measurements of dispersion measure (DM) and rotation measure (RM). The structure function of DM shows evidence of turbulence in the gas in the cluster, while the structure function of RM does not. Future pulsar discoveries in the cluster could help confirm the presence and localize the turbulence.