  PSR J1119-6127 is a radio pulsar that behaved magnetar like bursts, and we
performed a comprehensive investigation of this pulsar using the archival
high-energy observations obtained after its outburst in 2016 July. After the
2016 outburst, specific regions on the neutron star surface were heated up to >
0.3 and > 1 keV from about 0.2 keV. A hard non-thermal spectral component with
a photon index < 0.5 related to the magnetospheric emission can be resolved
from the NuSTAR spectra above 10 keV. We find that the thermal emitting regions
did not cool down and gradually shrank by about (20-35)% four months after the
outburst. Hard X-ray pulsations were detected with NuSTAR immediately after the
outburst, at 5 sigma confidence level and with a background-subtracted pulsed
fraction of (40+-10)%. However, the signal became undetectable after a few
days. Using Fermi data, we found that the gamma-ray emission in 0.5-300 GeV was
suppressed along with the disappearance of the radio pulsations. This is likely
caused by a reconfiguration of the magnetic field. We also discovered that the
timing noise evolved dramatically, and the spin-down rate significantly
increased after the 2016 glitch. We proposed that post-outburst temporal and
spectral behaviors from radio to gamma-ray bands were caused by changes of the
magnetosphere structure, pair plasma injection and the shrinking emission sites
on the neutron star.
