PSR J2222-0137 pulsar timing results. (Xueli Miao processes data)
PSR J2222 0137 is a massive pulsar with a massive white dwarf companion in a 2.44-day orbit (Boyles et al. 2013). With a DM of only 3.28 pc cm^-3, this has the most precise VLBI distance for any pulsar, 267.3 pc. This distance implies that we can calculate kinematic corrections to the orbital decay of this system more precisely than for any other system. The masses of the system are measured with good precision (Guo et al. 2021); This combination of well-known and unusual pulsar
mass, and the precisely known kinematic corrections for this system make it one of the most powerful laboratories for testing the the nature of gravitational waves and for searching for the phenomenon of “spontaneous scalarization” in strong-fifield gravity, a prediction of some alternative theories of gravity (Zhao et al. 2021).
We have done 17 observations, 30 minutes each by FAST. To reduce jitter noise, we choose 5 min integration time.
We use J2222-0137_T1_DDGR.par that do not include DMX to fit.
These are fitting results with all parameters fixed.
These are fitting results with F0 and F1 free.
These are fitting results with all parameters free.
We use J2222-0137_T1_DDGR.par that include DMX 30 to fit. We set 32 sub-band for frequency and 5-min per TOA and get:
These are fitting results with all parameters fixed.
These are fitting results with F0 and F1 free.
We can not make all parameters free to fit in this case.
