Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), astronomers from Nanjing University and elsewhere have made a significant discovery related to a supernova remnant known as CTB 87.
Background on Pulsars
Pulsars are highly magnetized, rotating neutron stars emitting electromagnetic radiation. They are commonly detected through radio emission, although they can also be observed using optical, X-ray, and gamma-ray telescopes.
Characteristics of CTB 87
CTB 87 is a plerionic supernova remnant with an X-ray luminosity nearly 100 times weaker than the Crab Nebula in the 0.15−3 keV band. It hosts a pulsar wind nebula (PWN) with trailing morphology in X-rays.
Discovery of PSR J2016+3711
A team of astronomers led by Nanjing University’s Qian-Cheng Liu investigated a point-like X-ray source in CTB 87, designated CXOU J201609.2+371110, and discovered radio pulses from this source using FAST.
Characteristics of PSR J2016+3711
PSR J2016+3711, located about 43,400 light years away, has a spin period of 50.8 milliseconds and a dispersion measure of approximately 428 pc/cm3. Its spin-down luminosity is measured at 22 undecillion erg/s, with a characteristic age of 11,100 years.
Magnetic Field Strength and Pulse Profile
The equatorial surface dipole magnetic field strength of PSR J2016+3711 is approximately 1.9 TG. The radio pulse profile of this pulsar is narrow, suggesting either an intrinsically narrow radio beam or a line of sight that sweeps across a small segment of a broad beam.
Gamma-ray Emission Analysis
Although many pulsars emit gamma-rays, analysis of data from NASA’s Fermi spacecraft did not detect gamma-ray pulsation from PSR J2016+3711. Further observations are required to definitively determine its gamma-ray emission properties.
Conclusion and Future Directions
More follow-up radio observations are recommended to obtain a more accurate timing solution, which could aid in folding the gamma-ray data and searching for pulsations from PSR J2016+3711.
Multiple-Choice Questions (MCQs):
- What instrument was used to detect radio pulses from the pulsar in CTB 87?
- A) Hubble Space Telescope
- B) Spitzer Space Telescope
- C) Five-hundred-meter Aperture Spherical radio Telescope (FAST)
- D) Chandra X-ray Observatory
- Answer: C) Five-hundred-meter Aperture Spherical radio Telescope (FAST)
- What is the spin period of PSR J2016+3711?
- A) 5.8 milliseconds
- B) 10.8 milliseconds
- C) 50.8 milliseconds
- D) 100.8 milliseconds
- Answer: C) 50.8 milliseconds
- What is the equatorial surface dipole magnetic field strength of PSR J2016+3711?
- A) 0.5 TG
- B) 1.0 TG
- C) 1.9 TG
- D) 2.5 TG
- Answer: C) 1.9 TG
- Which telescope was used to search for gamma-ray pulsation from PSR J2016+3711?
- A) Hubble Space Telescope
- B) Spitzer Space Telescope
- C) Fermi spacecraft
- D) Chandra X-ray Observatory
- Answer: C) Fermi spacecraft