The Absolute Cosmos: The mystery behind surprising neutron star system revealed after two decades

Image credit: University of Manchester

Almost after more than twenty years, an international team of scientists has revealed the mysterious source of gamma rays. It is a heavy neutron star with a very low mass partner orbiting around it.

By looking deep into the data from NASA’s Fermi satellite, the team detected the neutron star by its gamma rays pulsating regularly.

Scientists used novel data analysis methods operating on about ten thousand graphic cards in the distributed citizen science project called Einstein@Home.

To the much of their surprise the neutron star is completely invisible in radio waves. The binary system was distinguished by conducting observations across the electromagnetic spectrum.

The neutron star spins on its axis at more than thirty thousand rpm, designating it one the fastest spinning.

The magnetic field of neutron star is exceptionally weak, which is quite uncommon, as they usually have strong magnetic fields.

The scientific observations from 2014 helped in identifying the properties of binary star’s orbits.

Scientists knew that the neutron star is behind the source of gamma rays since 1999 and was viewed as plausible since 2009.

It was only after 2014 observations of the system with X-ray and optical telescopes, it was established that it is a pretty tight binary system. But so far all the efforts to look for neutron star returned unsuccessful.

In order to confirm the presence of a neutron star, not just radio waves or gamma rays, but also the characteristic pulsations of the star needs to be detected.

The spinning of the neutron star is responsible for the regular pulsations, thus giving it the name of a radio or gamma-ray pulsar respectively.

Binary systems like the one discovered recently are called “black widows” — like the spiders of the same name as they eat their companions.

The black widow pulsar evaporates its partner with its radiation, stuffing the star system with plasma which is impenetrable to radio waves.

This is the first spider pulsar detected through joint efforts of Jodrell Bank and the Albert Einstein Institute.

There are a few more Spider binary candidates simply like this one, which are continuously being monitored with optical telescopes to determine their orbital periods.

The new binary system and neutron star at its heart has been named PSR J1653–0158.

A little more than twice the mass of our Sun, the neutron star is remarkably heavy. Its partner is only one percent the mass of our Sun and the couple orbits every seventy five minutes.

After detecting gamma ray pulsar, the team looked for its radio waves. For that scientists used the most sensitive and largest radio telescopes in operation, including Jodrell Bank’s Lovell Telescope. But they found no trace of radio waves.

Because of no detection of radio waves, PSR J1653–0158 becomes the second fastest spinning pulsar from which radio waves are not seen.

Scientists propose two possible explanations for this: either the pulsar is not sending radio waves towards Earth or most probably the binary star system is covered in plasma clouds completely so that radio waves are not reaching Earth.

Further, scientists also looked into the data from The Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors for possible gravitational waves that neutron star would emit, but again the results were big No No.



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Absolute Cosmos

Absolute Cosmos

The Cosmos is all that is or ever was or ever will be…