Supermassive black holes found hiding in Milky Way’s backyard

9 Jan 2017

Galaxy NGC 1448. Image: Carnegie-Irvine Galaxy Survey/NASA/JPL-Caltech

Our galactic neighbours have been hiding enormous black holes like “monsters under your bed” behind enormous plumes of gas and dust, according to new research.

Black holes remain one of the most fascinating phenomena in the universe, chiefly for its ability to rip apart the very fabric of space-time, with nothing capable of escaping the black void.

New research from Durham University (DU) in the UK has discovered that in neighbouring galaxies to our own Milky Way, there are two enormous black holes that have been hiding behind enormous plumes of dust and gas.

According to the research team from DU, two supermassive black holes were found in the centres of nearby galaxies and are the central engines of what astronomers call “active galactic nuclei”, a class of extremely bright objects that includes quasars and blazars.

While many of the telescopes used today would be incapable of spotting these objects, the black holes give themselves away when looking through NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array) via emitted high-energy x-rays.

These active galactic nuclei are incredibly bright due to the intense heat and radiation created by particles coming in contact with the area surrounding the black hole, but hidden by a doughnut-shaped cloud of gas and dust.

Finding these two black holes has proven difficult in the past because astronomers have been viewing them edge-on, obscured by this thick cloud, receiving only a fraction of reflected x-rays.

Monsters underneath the bed

“These black holes are relatively close to the Milky Way, but they have remained hidden from us until now,” said Ady Annuar, who presented the results at the recent American Astronomical Society meeting in Texas. “They’re like monsters hiding under your bed.”

Of the two galaxies, NGC 1448 was found to be the most surprising, given that despite its enormous size and proximity of just 38m light years away, it has only been discovered recently.

NuSTAR has also discovered that this galaxy has a large population of young stars just a few millions years old, and this supermassive black hole is feeding on the gas and dust that surrounds it.

When not hiding from view, some black holes have been found to create as much as they destroy, with a recent simulation noting that thousands of planet-sized objects could be drifting through the universe, having been created by the ripping apart of stars.

Colm Gorey was a senior journalist with Silicon Republic