Researchers have registered three potential occasions of thetidal destruction of stars at the hands of supermassive black holes at the center of their galaxies.
The MIPT and the Space Research Institute of the Russian Academy of Sciences researchers made their findings by looking at data from the X-ray orbiting observatories ROSAT and XMM-Newton, the Moscow Institute of Physics and Technology reported.
A star in a galaxy passes closely enough to a black hole to be destroyed about once every 10,000 years. When a star is destroyed by these objects it emits an ultra-bright X-ray flare that is detectable to scientists. The difficult part is distinguishing this type of flare from other sources of X-ray light in the universe.
The researchers developed a number of methods for distinguishing these star deaths from other occurrences. The first step is eliminating flares that occur in our own galaxy, since there is only one supermassive black hole at the center of the Milky Way stars could not have fallen victim to it at the edges of our galaxy. Sources of radiation that were too large were also excluded.
A supermassive black hole takes only a few years to absorb all of the matter from a destroyed star, so observations a decade after the event should reveal a significant dimming of the X-ray source. The researchers obtained data from the 1990s and early 2000s, and were able to determine which sources had dimmed.
The data pinpointed three X-ray sources: labeled1RXS J114727.1 + 494302, 1RXS J130547.2 + 641252 and 1RXS J235424.5-102053. There is another potential source that may be a destroyed star, but the data does not allow researchers to distinguish it from the nucleus of its galaxy. The new data suggests the destruction of stars from black holes occur about once every 30,000 years within galaxies.
While the findings are still uncertain, the researchers hope to gain more insight through the launch of the Spectrum-X-Gamma in 2016, which will carryout eight new X-ray sky surveys within four years.
The findings have been accepted for publication in the Monthly Notices of the Royal Astronomical Society.
