Our cosmic backyard harbours hidden black holes, says NASA!

NGC 1448, a galaxy with an active galactic nucleus hidden by gas and dust (Left). IC 3639, also contains an example of an obscured supermassive black hole. (Right) (Image courtesy: Carnegie-Irvine Galaxy Survey/NASA/ESO/JPL-Caltech/STScI)

New Delhi: Black holes and their behaviour have been long since been no less than an enigma for scientists to decipher.

Found in abundance in the universe, these gravity-pulling black holes have always been known to exist in distant galaxies.

Now, in a somewhat eye-opening revelation, NASA has discovered two gas-enshrouded supermassive black holes, located at the centers of nearby galaxies.

Monster black holes, it seems, also sometimes lurk behind gas and dust, hiding from the gaze of most telescopes.

However, they tend to give themselves away when material they feed on emits high-energy X-rays that NASA's NuSTAR (Nuclear Spectroscopic Telescope Array) mission can detect. That's how NuSTAR came across these two elusive ones.

These black holes are relatively close to the Milky Way, but they have remained hidden from us until now," said Ady Annuar, a graduate student at Durham University in the United Kingdom, who presented the results at the American Astronomical Society meeting in Grapevine, Texas. "They're like monsters hiding under your bed," NASA reported.

NASA further explained that both of these black holes are the central engines of what astronomers call "active galactic nuclei," a class of extremely bright objects that includes quasars and blazars. Depending on how these galactic nuclei are oriented and what sort of material surrounds them, they appear very different when examined with telescopes.

"Just as we can't see the sun on a cloudy day, we can't directly see how bright these active galactic nuclei really are because of all of the gas and dust surrounding the central engine," said Peter Boorman, a graduate student at the University of Southampton in the United Kingdom.

NGC 1448 and IC 3639 are the two black holes identified by the American space agency.