First detection of frequency-dependent, time-variable dispersion measures
First detection of frequency-dependent, time-variable dispersion measures
Context. High-precision pulsar-timing experiments are affected by temporal variations of the dispersion measure (DM), which are related to spatial variations in the interstellar electron content and the varying line of sight to the source. Correcting for DM variations relies on the cold-plasma dispersion law which states that the dispersive delay …