Milli second burst detected by Astrosat

Source- This post is based on the article “Milli-second burst detected by AstroSat in new high magnetic field neutron star can help understand such stellar entities” published in “PIB” on 25th December 2023.

Why in the News?

Recently a study revealed that AstroSat (India’s first multi-wavelength space observatory) has detected intense sub-second X-ray bursts from a new neutron star ‘SGR J1830-0645’.

What is ‘SGR J1830-0645’?

1) SGR J1830-0645 (a magnetar) is a relatively young and solitary neutron star, with an age of approximately 24,000 years.

2) It was first identified in October 2020 by NASA’s Swift spacecraft

What are Magnetars?

1) Magnetars are neutron stars with an ultrahigh magnetic field that are much stronger than the terrestrial magnetic field.

2) The emission of high-energy electromagnetic radiation in magnetars is powered by the decay of their magnetic fields.

3) They also exhibit strong temporal variability, featuring slow rotation, rapid spin-down, and bright, short bursts, sometimes extending to months-long outbursts.

What are the findings of the study?

1) Researchers from Raman Research Institute (RRI) and the University of Delhi analyzed the timing and spectra of this magnetar using two instruments on AstroSat: the Large Area X-Ray Proportional Counter (LAXPC) and the Soft X-Ray Telescope (SXT).

2) A notable discovery included identifying 67 brief sub-second X-ray bursts, averaging a duration of 33 milliseconds. The most luminous burst among them endured for approximately 90 milliseconds.

3) It detected bright sub-second X-ray bursts which can help understand the intriguing extreme astrophysical conditions of magnetars.

4) The study concluded that SGR J1830–0645 is a unique magnetar that showcased emission line in its spectra. The presence of emission lines and its potential origin — either due to fluorescence of iron, proton cyclotron line feature or an instrumental effect — remains a subject of consideration.

5) The research team intends to broaden their study to determine the origin of these energetic emissions, discerning whether they have an astrophysical origin or are instrumental in nature.

What is Astrosat?

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