The Angular Broadening of the Galactic Center Pulsar SGR J1745-29: A New Constraint on the Scattering Medium

Understand

The pulsed radio emission from the Galactic Center (GC) magnetar SGR J1745-29 probes the turbulent, magnetized plasma of the GC hyperstrong scattering screen through both angular and temporal broadening.

• We present the first measurements of the angular size of SGR J1745-29, obtained with the Very Long Baseline Array and the phased Very Large Array at 8.7 and 15.4 GHz.
• The source sizes are consistent with the scatter--broadened size of Sagittarius A* at each frequency, demonstrating that SGR J1745-29 is also located behind the same hyperstrong scattering medium.
• Combining the angular broadening with temporal scattering obtained from pulsar observations provides a complete picture of the scattering properties.