Astronomers from Nanjing University in China, utilizing the Five-hundred-meter Aperture Spherical radio Telescope (FAST), sheds light on the enigmatic CTB 87 supernova remnant. Published on February 1 on the arXiv pre-print server, their findings reveal the detection of a radio pulsar within CTB 87, a significant milestone in understanding these celestial phenomena.
Pulsars, characterized by their intense magnetic fields and rapid rotation, emit beams of electromagnetic radiation detectable across various wavelengths, including radio, optical, X-ray, and gamma-ray spectra. CTB 87, a plerionic supernova remnant, stands out with its subdued X-ray luminosity compared to counterparts like the Crab Nebula, yet it hosts a pulsar wind nebula (PWN) in X-rays, a phenomenon not uncommon in similar remnants.
The focal point of this investigation, designated CXOU J201609.2+371110, drew attention due to its point-like X-ray emissions. Through meticulous analysis, the researchers identified radio pulses emanating from this source, confirming its compact nature and marking the first detection of a pulsar in CTB 87 using FAST.
The newfound pulsar, named PSR J2016+3711, resides approximately 43,400 light years away and boasts a spin period of 50.8 milliseconds, along with a dispersion measure of around 428 pc/cm³. Its spin down luminosity and characteristic age were measured at 22 undecillion erg/s and 11,100 years, respectively, offering insights into its evolutionary trajectory.
Further investigation revealed the equatorial surface dipole magnetic field strength of PSR J2016+3711 to be at a level of 1.9 TG. Notably, the radio pulse profile exhibited a narrow configuration without broad wings, suggesting either an intrinsically narrow radio beam or a fortuitous alignment of the line of sight with a small segment of a broader emission cone.
In a bid to unveil potential gamma-ray emissions, the team scrutinized data from NASA’s Fermi spacecraft but found no conclusive evidence of gamma-ray pulsation from PSR J2016+3711. However, they underscored the necessity for continued observations to conclusively ascertain its gamma-ray emission status.