NASA Telescopes Reveal Hidden Properties of X-Ray Pulsar RX J0032.9-7348

Pulsars are neutron stars rotating rapidly, emitting electromagnetic radiation in various wavelengths, including radio waves, optical, X-ray, and gamma-ray. Identified as a X ray transient source in the Small Magellanic Cloud (SMC) about 30 years ago, RX J0032.9-7348 has been classified as an X-ray Pulsar after detecting X-ray pulsations with a period of approximately 7.02 seconds after experiencing an X-ray brightening in October 2024.To take a closer look at it, astronomers have incorporated two NASA X-ray telescope, NICER and NuSTAR.

Discovery and Observational Campaign

According to Handbook of X-ray and Gamma ray Astrophysics, Accretion-powered X-ray pulsars (XRPs) are neutron stars within binary systems that emit X-rays in regular pulses, powered by the accretion of matter from a companion star. However, although RX J0032.9-7348 has been known for decades, very little is known regarding its properties and its optical counterpart has not been identified. Therefore, a team of astronomers led by Birendra Chhotaray of the Physical Research Laboratory (PRL) in Ahmedabad, India, decided to take a closer look at this pulsar with NuSTAR and NICER.
Dr Chhotaray and his team were able to verify the X-ray pulsation period of RX J0032.9-7348 through their observations and they also discovered that this pulsar has a double-peak pulse profile throughout a wide energy range, with small changes in the form of energy dependence.

Findings

Results of the observational campaign, published on the arXiv preprint server, gives insight of the spin dynamics and luminosity of this pulsar. The accretion processes during the X-ray brightening phase increases its angular momentum. It results into a spin-up of approximately -0.00033 seconds per day.
The luminosity of the pulsar varied from 8.2 undecillion to 37 undecillion erg/s during the monitoring campaign. The researchers report that no evidence of iron emission line or cyclotron resonance scattering features was found in the energy spectrum of this source.