Speaker: Jompoj Wongphecauxson (chair: Tasha Gautam)
Title: Discovery of a Galactic centre pulsar J1746-28
Pulsars are the highly magnetized rotating neutron stars, the remnants of intermediate mass stars (8-25 Solar mass), that emit electromagnetic radiation, mostly detected at radio frequencies. The rotation periods of pulsars to date are ranging from 1.3 milliseconds to 21.5 seconds. Pulsars areused as tools to study many physical phenomena, for example mapping the distribution of interstellar medium in the Galaxy and testing the General relativity theory. Typically the Fast Fourier Transform (FFT) is used to search for repeating signals. However, the FFT has some limitations on detecting long-period pulsars. The Fast Folding Algorithm (FFA), which is computationally more expensive than the FFT, is used to overcome this limit and has been applied to the reprocessing of HTRU-S low lat survey. This survey is one of the most sensitive blind pulsar surveys to date. This work has already led to the discovery of J1746-28.
A new pulsar J1746-28, located approximately 0.5 degrees from the Galactic centre, was discovered with a period of 1.89 seconds. J1746-28 has a similar distance ( approximated from the amount of a free electron distribution model) as other Galactic centre pulsars. By using this electron density model, the separation of pulsar from the Galactic centre is just ~72 pc. J1746-28 processes the possibility to probe the ISM and the interstellar magnetic field around the Galactic centre on a different scale than before.