A recent analysis on data from 170,000 black holes casts doubt on the theory that black holes tend to be surrounded by a doughnut-shaped ring of gas and dust. The real nature of black holes, and their stellar environment, might be much more complex that had been theorized.
The theory holds that black holes are surrounded by a cloud of gas and dust that forms a torus surrounding the black hole itself. The size and shape of that torus would appear to vary depending on orientation. Viewed edge-on the torus would look like a ring of gas. From another angle, the ‘doughnut’ may look different.
The data from NASA’s Wide-field Infrared Survey Explorer(WISE) provided the raw material for this study. The new review of WISE data focused on active supermassive black holes that lie in the center of many, if not all, galaxies include our own Milky Way. An active black hole is one that feeds on surrounding gas and dust.
A black hole has such a powerful gravity field that no light escapes, but the surrounding gas and dust are visible. This is how astronomers find and analyze black holes. The theory holds that all black holes are surrounded by such a ring of material. WISE images show that some black holes are out in the open and easy to see from their effects on surrounding matter. Other black holes are hidden inside huge clouds of gas and dust.
The new data from WISE cast doubt on the unified theory of black holes. Results were accepted for publication in Astrophysical Journal. Study co-author Emilio Donoso said that something other than the expected ring of gas and dust is obscuring some black holes. The nature of that material is still undetermined. Those black holes tend to be in clusters of galaxies, rather than scattered at random throughout space.
The doughnut theory became popular in the 1970s. The theory, technically known as the unified theory marked a first attempt to explain why black holes vary so much in outward appearance. The unification model was meant to assemble a variety of objects into one model of the cosmos, Donoso said.
The WISE data are making that task increasingly difficult. The new study does not offer an explanation for the odd clustering of black holes. NASA data do seem to cast doubt of a dominant theory about black holes.
Dark matter may be relevant, according to NASA. Dark matter is one or more types of invisible matter. While astronomers are not sure what dark matter is, they do know it has far more mass than all of the visible matter in the cosmos.
All galaxies appear to be surrounded by vast halos of dark matter. Those black holes are hidden in the centers of galaxies known to have larger dark matter halos. Though dark matter itself cannot be responsible for hiding the black hole, the existence of that dark matter might hint at what is happening.
NASA launched WISE in December 2009. The satellite spent the following 10 months surveying the infrared part of the night sky. It ran out of hydrogen coolant in October of 2011 and was decommissioned in February of 2011, after taking millions of photographs. The analysis of black hole images is one of many studies using WISE images.
Scientists have made a number of other discoveries by going over WISE data. Astronomers have found new comets, thousands of asteroids in asteroid belt and 134 ‘near-Earth objects’, which are objects that come within 28 million miles of Earth at some point. The new analysis of NASA’s black hole data casts doubt on the theory about how black holes work. This is just one more of a string of discoveries to come from WISE data.
By Chester Davis