NASA's Fermi Gamma-ray Space Telescope has spotted a record breaking gamma-ray binary named LMC P3 close to Milky Way galaxy.
LMC P3 is the brightest of about five gamma-ray binaries found by far and it also gets the credit of first gamma-ray binary detected in a galaxy outside the Milky Way, where our planet Earth exists. The brightness of the system is attributed to gamma rays produced as a result of interaction between a massive star and the crushed stellar core. Gamma rays are known to be the "highest-energy form of light."
When a neutron star or a black hole interacts with a normal star it results in cyclic emission of gamma rays, such light emitting systems are referred to as gamma-ray binaries. The luminous gamma-ray binary is detected in the Large Magellanic Cloud (LMC) just next to Milky Way. The orbital period of the system is reported to be 10.3 days.
Robin Corbet, lead researcher at NASA's Goddard Space Flight Center in Greenbelt, Maryland noted in the press release that NASA's Fermi Telescope has detected a brightest gamma-ray binary outside the Milky Way Galaxy. Corbet added that about five such systems found earlier are from Milky Way and nothing is as distant as the new one.
The researcher noted that gamma-ray binaries are significant because the emission output is observed to change during each orbit and sometimes with time. Therefore detection of such systems is of great help to have a clear understanding of many such emission processes linked to gamma rays.
LMC P3 is reported to be lying inside the debris of supernova explosion in LMC. The LMC, which is a small galaxy, exists at just 163,000 light-years away from Milky Way. Earlier in 2012, the researchers from NASA's Chandra X-ray Observatory, found an x-ray source in the supernova orbiting a young star many folds bigger than the sun. The scientists back then named it as high-mass X-ray binary (HMXB).
"The source is significantly more luminous than similar sources in the Milky Way, at radio, optical, X-ray, and gamma-ray wavelengths," reports the study published in The Astrophysical Journal. "The detection of this extra-galactic system, but no new Galactic systems, raises the possibility that the predicted number of gamma-ray binaries in our Galaxy has been overestimated, and that HMXBs may be born containing relatively slowly rotating neutron stars."
Guillaume Dubus, from Institute of Planetology and Astrophysics of Grenoble in France said that it is a huge surprise to have found a gamma-ray binary in another galaxy when there are lot of such systems in our own galaxy waiting to be detected.
Photo: NASA Goddard Space Flight Center | Flickr
