Orateur
Description
DR3 will add low-frequency data from LOFAR and NenuFAR. A characteristic of low-frequency pulsar observations is their high sensitivity to the diverse effects of propagation through a plasma. Adding these data is thereby useful for determining the various chromatic noises more accurately. In addition to being more sensitive to interstellar medium variations, low-frequency data become sensitive to smaller DM variations within the Solar System due to the solar wind contribution.
Contrary to purely stochastic DM and other chromatic variations, those from the solar wind are based on an annual variation, as well as an 11-year variation due to the solar cycle. The software run_enterprise allows for the fitting of this annual variation. For now, we have applied it to the DR2low data from J1022+1001 and J0030+0451. And we modified it to fit the solar cycle variations in addition to the annual ones. We will present some initial results for these two pulsars.
A better consideration of these various solar wind variations could significantly improve the PTA sensitivity. Moreover, in the reverse direction, the PTA analysis could help in defining the solar wind model more accurately, which will ultimately also improve the PTA sensitivity.