Dispersion and Rotation Measure of Supernova Remnants and Magnetized Stellar Winds: Application to Fast Radio Bursts

Understand

Recent studies of fast radio bursts (FRBs) have led to many theories associating them with young neutron stars.

• If this is the case, then the presence of supernova ejecta and stellar winds provide a changing dispersion measure (DM) and rotation measure (RM) that can potentially be probes of the environments of FRB progenitors.
• Here we summarize the scalings for the DM and RM in the cases of a constant density ambient medium and of a progenitor stellar wind.
• Since the amount of ionized material is controlled by the dynamics of the reverse shock, we find the DM changes more slowly than in previous simpler work, which simply assumed a constant ionization fraction.