Scientists have discovered the first gamma-ray pulsar in a galaxy other than the Milky Way, and it is the most luminous pulsar known to science.
The incredible object is located in the outskirts of the Tarantula Nebula in the Large Magellanic Cloud, which is a small galaxy orbiting our own, NASA's Goddard Space Flight Center reported. The galaxy is 163,000 light-years away, and is the largest, most active region in our galactic "neighborhood." Scientists initially mistook the glow of the pulsar for a collisions of subatomic particles caused by a supernova explosion. The findings were made using NASA's Fermi Gamma-ray Space Telescope.
"It's now clear that a single pulsar, PSR J0540-6919, is responsible for roughly half of the gamma-ray brightness we originally thought came from the nebula," said lead scientist Pierrick Martin, an astrophysicist at the National Center for Scientific Research (CNRS) and the Research Institute in Astrophysics and Planetology in Toulouse, France. "That is a genuine surprise."
When a star explodes as a supernova, its core can survive as a neutron star that spins rapidly and emits magnetic field powers beams of radio waves, X-rays, gamma rays, and visible light. When these beams move past Earth astronomers can spot a pulse of emissions, giving them the name pulsars.
"The gamma-ray pulses from J0540 have 20 times the intensity of the previous record-holder, the pulsar in the famous Crab Nebula, yet they have roughly similar levels of radio, optical and X-ray emission," said coauthor Lucas Guillemot, at the Laboratory for Physics and Chemistry of Environment and Space, operated by CNRS and the University of Orléans in France. "Accounting for these differences will guide us to a better understanding of the extreme physics at work in young pulsars."
J0540 is only about 1,700 years old; while more than 2,500 known pulsars are from 10,000 to hundreds of millions of years old. The Crab Nebula pulsar is about half of J0540's age.
The findings were published in a recent edition of the journal Science.
