Daily Image
27-01-2021
First confirmation of Solar-wind variability in pulsar timing
| Submitter: | Caterina Tiburzi |
| Description: | Pulsar analyses are affected by the temporal variability in the `dispersion measure` (DM), i.e. the column density of free electrons along the line-of-sight (LoS). While DM variability caused by the interstellar medium is well-known in literature, Solar wind-induced DM fluctuations have never been confirmed. In a recent work based on high-quality, high-cadence data collected with the LOFAR core and the international stations, we provided the first clear evidence of DM variability due to the Solar wind, that appears to be coupled with the Solar cycle. In particular, the image reports the DM time series along the LoS of pulsar J2145-0750 (top panel), the same time series removed of interstellar medium effects (middle panel) and removed of both the interstellar medium effects and a toy Solar-wind model (bottom panel). The timespans during which the pulsar is passing closer than 50 degrees from the Sun are highlighted in red. The highlights most clearly show that the Solar wind effects decrease with the Solar cycle, reaching the largest magnitude during the Solar maximum and the minimal impact towards the Solar minimum. (The related article "The impact of Solar wind variability on pulsar timing" has been accepted for publication in A&A) |
| Copyright: | C. Tiburzi |
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