Detecting black holes: A new way of detecting active black holes and measuring the amount of matter they suck in has been determined by astronomers. Researchers at the University of Western Australia node of the International Centre for Radio Astronomy Research (ICRAR) have said that the new technique would help in finding bright, supermassive black holes at the centres of millions of galaxies. Till now, bright black holes have been identified with much difficulty by astronomers, who have had to specifically look for them using techniques that are complex and also unique to the different types of telescopes. However, the new technique, as per the researchers, is based on typical telescope observations that have already been collected for millions of galaxies.
A statement by ICRAR cited lead author Jessica Thorne, who is a PhD student, as saying that active black holes are typically located among the largest galaxies, and the ones that they are looking for are a million to a billion times as massive as our Sun. She added that as these black holes suck in surrounding matter, the matter becomes superheated due to the friction and, as a result, becomes very luminous, leading to the active black holes becoming bright enough to even outshine the rest of the galaxy.
Using this new technology, astronomers will have the ability to identify such active black holes and determine the amount of light they are emitting. But they would also be able to measure the properties of the galaxy these black holes are located in simultaneously. Doing both the things at once would allow astronomers to get a clearer idea of the impact of the black hole on its galaxy.
The new technique was developed by researchers using an algorithm called ProSpect which models emissions from galaxies as well as black holes while light is at different wavelengths. This method was then applied to more than half a million galaxies.
Throne said that one of the reasons such black holes were ignored in the past was because it was difficult to find all of them, and astronomers do not really understand bright black holes sufficiently to include them in modelling studies in proper detail.
The statement also cited Dr Bellstedt as saying that the new technique was more thorough, more consistent as well as easier, allowing astronomers to search for active black holes in a lot more places than they could before. This would also aid in the search for more galaxies and help astronomers look at what happened to the Universe further back in time.