Radio signals from the wind nebula of supernova CTB 87 – a new step towards understanding the evolution of supernovae
Using the FAST radio telescope with a 500-meter aperture, astronomers from Nanjing University and their colleagues from other countries discovered a radio pulsar in the supernova remnant CTB 87. This radio telescope is the largest in the world, and its use allows the study of space objects with high resolution and improved sensitivity.
Pulsars are special types of neutron stars that rotate on their axis at fast speeds and have a strong magnetic field. They emit regular pulses of radio waves, similar to a beacon shining in the Universe. However, not all pulsars appear only in the radio range. Some of them are also excited in the optical, x-ray and gamma ranges.
CTB 87 is a single supernova that was formed by the explosion of a star. Supernova remnant CTB 87 has been studied in various wavelengths, including X-rays. However, the interaction of pulsar emissions with the environment has not yet been discovered.
A team of astronomers led by Professor Qian-Cheng Liu from Nanjing University identified a point source of X-ray radiation, designated CXOU J201609.2+371110, in the supernova remnant CTB 87. Using the FAST radio telescope, they detected radio pulses from this point source. The pulsar, which has been named PSR J2016+3711, is located about 43,400 light years away and has a rotation period of 50.8 milliseconds and a dispersion measure of approximately 428 pc/cm3. The pulsar’s age is estimated at 11,100 years.
Interestingly, this is the first pulsar discovered in supernova remnant CTB 87 using the FAST radio telescope. The researchers also noted that the field of view from which the radio beam of this pulsar emanates is most likely narrow and may be associated with its magnetic polar cap.
Given that some pulsars also emit gamma rays, the team of astronomers analyzed data from the Fermi Gamma-ray Space Telescope to check for gamma ray pulsations from PSR J2016+3711. However, in this case, gamma radiation pulsations were not detected. The study authors note that additional observations over a long period of time are needed to obtain more accurate results and definitively exclude a connection between the pulsar and gamma radiation.
“Follow-up radio observations spanning several years would be useful to obtain more precise data that could be used to stack gamma-ray data and search for pulsations,” the study authors concluded.