A team of scientists led by an Indian and a Spanish scientist explored the reasons for short duration explosion of Magnetar—a neutron compact star, which could be 20-30 times heavier than the sun, but less than the size of Delhi, and releases energy almost 100000 times more than the energy of Sun.
This is for the first time that scientists studied this Magnetar in detail and found clues to understand the sudden violent short duration flares in a fraction of a few milliseconds, claimed a senior officer of the Ministry of Science and Technology here on Thursday.
The present magnetar (GRB20014155) studied by the scientists exploded on April 15 last year. It lasted only one-tenth of a second and released energy equivalent to the energy that the Sun would radiate in one lakh years, said a senior officer of the Ministry of Science and Technology here on Thursday.
He said, the two Indian Institutes—The Aryabhatta Research Institute of Observational Science (ARIES) and Institute of Department of Science and Technology, worked in close coordination with the Andalusian Institute of Astrophysics (IAA-SCIS) studied the magnetars eruption in detail to throw the light on the mysterious eruption of these compact neutron stars.
While the Indian team was led by Dr. Shashi Bhushan Pande (ARIES), the Spanish team was headed by Professor Alberto J Castro-Tirado (IAA-CSIS). They jointly published their research work in an international science journal—Nature.
The team studied a compact star (magnetars) of a rare category located thirteen million light-years away and reported the possible causes of their short and intense bursts—which has been surprising scientists for several decades.
So far, only 30 such magnetars have yet been recorded by scientists in our galaxy, the officer said, claiming that such explosions release transient x-ray pulses of energies—several times that of the Sun released in a fraction of millisecond to a few microseconds.
“When massive stars like supergiant stars with a total mass of between 10 and 25 solar masses collapse they might form neutron stars. Among neutron stars, stands out a small group with the most intense magnetic field known: magnetars,” the officer said.
“These objects, of which only thirty are known so far, suffer violent eruptions that are still little known due to their unexpected nature and short duration, of bare tenths of a second,” he said.
“The observations revealed multiple pulses, with a first pulse appearing only about tens of microseconds, much faster than other extreme astrophysical transients,” said Alberto J. Castro-Tirado, IAA-CSIC.
Professor Tirado said it was believed that eruptions in magnetars might be due to instabilities in their magnetosphere or to a kind of “earthquakes” (”starquakes”) produced in their crust, a rigid and elastic layer about a kilometer thick.
The eruption was detected by the Atmosphere-Space Interactions Monitor (ASIM) instrument, onboard the International Space Station. The scientific team was able to solve the temporal structure of the event, by analyzing the minute scale of data for over a year. “Though several papers have been published about the event, as ASIM was the only mission that detected the main burst phase in the entire energy range of photons without saturation, it puts the ASIM instrument in a unique position to unveil some of the secrets surrounding magnetars,” claimed the team of scientists which studied this phenomenon.