Dai, S.S.DaiJohnston, S.S.JohnstonWeltevrede, P.P.WeltevredeKerr, M.M.KerrBURGAY, MARTAMARTABURGAYEsposito, P.P.EspositoISRAEL, Gian LucaGian LucaISRAELPOSSENTI, ANDREAANDREAPOSSENTIRea, N.N.ReaSarkissian, J.J.Sarkissian2020-10-132020-10-1320180035-8711http://hdl.handle.net/20.500.12386/27768We present the spin frequency and profile evolution of the radio pulsar J1119 - 6127 following magnetar-like X-ray bursts from the system in 2016 July. Using data from the Parkes radio telescope, we observe a smooth and fast spin-down process subsequent to the X-ray bursts resulting in a net change in the pulsar rotational frequency of ∆ν ≈ -4 × 10<SUP>-4</SUP> Hz. During the transition, a net spin-down rate increase of ∆ \dot{ν }≈ -1× 10^{-10} Hz s<SUP>-1</SUP> is observed, followed by a return of \dot{ν } to its original value. In addition, the radio pulsations disappeared after the X-ray bursts and reappeared about two weeks later with the flux density at 1.4 GHz increased by a factor of 5. The flux density then decreased and undershot the normal flux density followed by a slow recovery back to normal. The pulsar's integrated profile underwent dramatic and short-term changes in total intensity, polarization, and position angle. Despite the complex evolution, we observe correlations between the spin-down rate, pulse profile shape, and radio flux density. Strong single pulses have been detected after the X-ray bursts with their energy distributions evolving with time. The peculiar but smooth spin frequency evolution of PSR J1119-6127 accompanied by systematic pulse profile and flux density changes are most likely to be a result of either reconfiguration of the surface magnetic fields or particle winds triggered by the X-ray bursts. The recovery of spin-down rate and pulse profile to normal provides us the best case to study the connection between high magnetic-field pulsars and magnetars.STAMPAenArticle10.1093/mnras/sty20632-s2.0-85055181092000449616200054https://academic.oup.com/mnras/article-abstract/480/3/3584/50635822018MNRAS.480.3584DFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation