An international teamof astronomers is planning to use gravitational wave data to unravelthe formation processes that created the first supermassive blackholes. These gargantuan black holes lurk at the centre of mostgalaxies, including our own Milky Way, playing a pivotal role ingalaxy formation and evolution.
So far astronomers havefailed to rally around a single theory to explain the creationprocess that produces supermassive black holes. Leading theoriesinclude the formation of black holes due to the collapse of a firstgeneration of colossal, ancient stars, or possibly a collisionbetween two ancient stellar bodies that formed part of a vast starcluster. Each of these theories would result in the gravitationalwaves thrown out by the creation event exhibiting a specific masssignature.
A new study led byscientists from Durham University used data from the two confirmedinstances of gravitational waves and fed it into a computersimulation known as the EAGLE project, which was supplemented by asimulation designed to calculate gravitational wave signals. EAGLE isin effect an attempt to create a detailed and faithful simulation ofthe large scale processes at work throughout the greater universe aswe currently understand them.
The results suggestthat future gravitational wave observatories, such as the proposedEvolved Laser Interferometer Space Antenna (eLISA) mission, will detect the minute ripples in the fabric of spacetimecreated by violent cosmic events roughly twice a year. eLISA willtake the form of three separate spacecraft working in perfect harmonyto form a laser interferometer similar to the LIGO instruments responsible for the initial detections of gravitationalwaves.
The eLISA spacecraft,which are set to launch in 2034, will orbit the Sun in a triangularformation, forming a vast interferometer 250,000 times larger thanthe detectors on Earth. The technology, a preliminary version ofwhich was recently tested via the LISA Pathfinder mission, will allowfor the detection of lower-frequency waves created by the collisionof black holes – each of which could be over a million times the massof the Sun.
By analysing theamplitude and frequency of the waves detected by missions such aseLISA, astronomers could ascertain the initial mass of the seeds ofthe earliest supermassive black holes which are thought to haveformed some 13 billion years ago – relatively soon after the creationof the universe. The existing theory that correlates most accuratelywith the gravitational wave data would then become the leading origintheory for the creation of supermassive black holes.
Source: University of Durham
