For more than two decades, astronomers have been systematically searching for mysterious sources of high-energy gamma rays in their sources.
One, however, remained stubborn – the most unknown source gamma rays in the galaxy. It appears to be 2,740 light-years away from the binary system, but only one star could not be found.
Now, astronomers have solved the mystery and finished the second star by finding gamma-ray data obtained between 2008 and 2018. Together, these two stars are the strangest binary system we have ever seen.
“The binary star system and the neutron star at its heart, now known as PSR J1653-0158, have set new records,” said Lars Nieder, an astronomer at the Albert Einstein Institute Hannover in Germany.
“We’ve discovered a galactic dance of a superweight with a flyweight: just over twice the mass of our Sun, the neutron star is extraordinarily heavy. Its companion has six times the density of lead, but it’s only 1 percent. Our solar mass.
“This ‘strange couple’ orbits every 75 minutes faster than any known comparative binary.”
Since at least 2009 it has been assumed that the gamma radiation received from the system must be produced by the gamma-ray pulsar. Then, in 2014, X-ray and optical observations of the source of the gamma rays created a variable star with a duration of 75-minutes.
This was a small companion star, and astronomers thought that the 75-minute period corresponded to orbital time, while the second star was a source of gamma rays.
Colin Clarke, an astronomer at the Jodrel Bank Center for Astrophysics at the University of Manchester in the UK, said: “All of their search for neutron stars has so far been in vain.
The second star was considered a pulsar. It is a kind of fast-moving neutron star that beams as radiation spins from its poles. It is a bit like a beam lighthouse, flashing (or pulsing) in front of the observer at the rate of rotation of the star. Radio pulsars are more common, but gamma-ray pulsars are also known.
To confirm the presence of another star, you need to find a timely pulsation with its orbit. So the team went hard. Using the computing power donated by thousands of members of the civic science program Einstein @ Home, they crushed a decade of gamma-ray data collected by the Large Area Telescope (LAT) on NASA’s Fermi Gamma-Ray Space Telescope.
In just two weeks, they got their pulsar.
It’s a little odd of course. The pulsar rotates very fast, more than 500 times a second. The millisecond pulsars rotate very fast; This is part of the “millisecond” part of their name. But PSR which is the fastest rotation rate found in 1653-0158 Pulsar.
In addition, the star has a very weak magnetic field. It is inside the bottom three of the pulsar magnetic field strength.
The fellow is also quite curious, as he has an incredibly low proportion. The team believes it is a helium white dwarf that has been cannibalized by a pulsar, leaving a residue. This type of system is known as ‘black widow’ binary.
“The dwarf star’s remnant orbits the Earth-Moon distance around the pulsar at a speed of only 700 kilometers per second (43 435 miles per second) in just 75 minutes.”
“This unusual epoch may have originated from a very close binary system, in which a neutron star originally flowed from an allied star, increasing its mass and causing it to rotate faster and faster while simultaneously wetting its magnetic field.”
(Kinspell / Clark / Max Planck Institute for Gravity Physics / NASA)
Above: Visualization of the system (bottom) compared to Earth and Moon (top).
This hypothesis is supported by the team’s search for radio waves. If pulsars emit any, we cannot detect them; This may be due to the fact that the system is surrounded by a cloud cloud of content from the decorated dwarf star. Gamma radiation can penetrate this cloud, but not radio waves.
Anyway, PSR J1653-0158 is just another millisecond pulsar that does not emit detectable radio waves.
“In a binary system like what we’ve found, pulsars are referred to as ‘black widows’ because, like spiders of the same name, they eat their partners, so to speak,” Clark said.
“The pulsar evaporates its mate from its radiation and particle winds, filling the star system with plasma that is impervious to radio waves.”
We find this system weird because of the technical limitations. With tools like Einstein @ Home, which essentially use idle computing time to provide super computing capabilities, we can be in the throes of a new era of pulsar discovery.
Bruce Allen, an astronomer at the Max Planck Institute for Gravitational Physics in Hannover, and Einstein’s founder and founder of Einstein, said: Home.
“But so far no one was able to send in the perfect solution, which is not strange. With Einstein @ Home, we hope to do it – who knows what other surprises will await us.”
Research has been published in Astrophysical Journal Letters.
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