|Description:|| [Donner et al. 2019, accepted for publication in A&A, https://arxiv.org/abs/1902.03814 ]|
We successfully detected frequency-dependent Dispersion Measures (DMs) in LOFAR observations using the HBAs of three international stations. We conclude that the effect is caused by different refraction angles at different frequencies, leading to the sampled volume of ISM being frequency-dependent. We present 3.5 years of observations of the slow pulsar J2219+4754.
The top panel shows the DMs measured at two parts of the LOFAR HBA band, while the bottom panel shows the difference in DM between the two parts of the band.
|Copyright:||Accepted for publication in A&A|