URUMQI, May 19 (Xinhua) -- Chinese astronomers have unveiled the mysterious origins of a young pulsar located in the Milky Way's halo, providing compelling observational evidence for the study of such objects' formation.
The study, conducted by a team from the Xinjiang Astronomical Observatory (XAO) of the Chinese Academy of Sciences, was recently published in the Astrophysical Journal.
By utilizing long-term observational data from China's Five-hundred-meter Aperture Spherical Radio Telescope (FAST), also known as the "China Sky Eye," and the 26-meter Nanshan Radio Telescope, the team tracked minute changes in the position of the young pulsar, named PSR J1740+1000. Combining this with its distance, they calculated its spatial velocity to be 329±80 km/s.
Based on this high velocity, researchers speculate that this young pulsar was born directly in the galactic halo. It is likely the offspring of a "runaway" OB star -- a massive star that was violently ejected from its native environment during a dramatic cosmic event.
In addition to tracing its origins, the team made a groundbreaking discovery in the pulsar's radio signals. By combining data from FAST and Australia's Parkes radio telescope, they identified multi-layered adjacent scintillation arc structures in the pulsar's secondary spectrum for the first time.
Further analysis suggests that these scintillation arcs likely originated from ionized structures on an astronomical unit scale within the pulsar's wind nebula (PWN).
According to Yao Jumei, an associate researcher at the XAO, a PWN is a plasma region formed by the interaction between the pulsar's high-speed particle flow and its surrounding environment.
She added that the findings indicate that the micro-scale structures of these nebulae play a dominant role in the formation of scintillation and can significantly affect the propagation of radio signals.
Pulsars are rapidly rotating neutron stars formed from the collapse of massive stars after they die. Traditionally, scientists believed that these objects are born in the Milky Way's disk, where stars are densely packed, rather than in its sparse outer halo.
This research not only provides key observational evidence for the origin of young pulsars in the galactic halo but also opens up new pathways for using pulsar signals to detect circumstellar and interstellar environments. ■
