Image Credit; Wikimedia Commons

I'm sure that many of you have heard black holes referred to as "cosmic vacuum cleaners." To a degree, that's true. Black holes do devour matter; however, contrary to popular belief, their gravitational pulls are no stronger than the gravitational pulls of other objects with a similar mass. Ultimately, this means that objects/material can (and do) orbit a singularity stably without becoming the prey of the immensely powerful black hole.

In fact, one of the hallmarks of black holes are the accretion disks that surround them. These disks of material form as a result of more matter piling up than the black hole can consume at any given time. Under certain circumstances, these doughnut-shaped disks become very hot and very luminous -- behavior that is typical of black holes in galaxies that experience lots of activity, known as "starburst" galaxies, or active galactic nuclei (AGN).


One active galaxy that is known to host a central supermassive black hole with an accretion disk is NGC 3783, located some 130 million light-years from Earth in the constellation of Centaurus. Not only does the galaxy make for a good study on the behavior and evolution of black holes in active galaxies, it also allowed astronomers to make some of the first observational evidence of so-called "molecular toruses," theoretical constructs comprised of molecular materials, such as gas and dust, that encircle accretion disks, obscuring them from view. If found to exist beyond mere computer simulations, a torus should be not only hot, but a strong source of x-ray flares and infrared emissions, possibly produced during consumption of a star as it is torn apart by the tidal forces.

Artist's rendition via : ESO/M. Kornmesser

However, when the European Southern Observatory recently set out to make new observations of the galaxy at infrared wavelengths, using its own "Very Large Telescope Interferometer," they saw something unexpected. Indeed, a torus was found surrounding the central black hole of NGC 3783, but the temperature of the dust was off kilter. Some of it came in at temperatures between 700 to 1000 degrees Celsius (1292 to 1832 F), while large quantities of cooler dust was found above and below the torus. So cool, in fact, that the dust would be at room-temperature if found on Earth.


The Cigar Galaxy is an active galaxy (Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)

According to Sebastian Hönig, the lead author of the paper:

“This is the first time we’ve been able to combine detailed mid-infrared observations of the cool, room-temperature dust around an Active Galactic Nuclei [AGN] with similarly detailed observations of the very hot dust. This also represents the largest set of infrared interferometry for an AGN published yet.”                                                         [Reference: ESO]

The team members believe this newly-discovered cool dust originates from chilly winds that bellow outwards from the central black hole, which brings out a new question.. does it jive with our current understanding between black holes and their surrounding environments? Apparently, not so much. Further observations must be made of NGC 3783 and similar black holes located in active galaxies. We clearly must be able to determine the affect both have on one another.


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-        "The Center of a Black Hole: Infinitely Massive Singularity or Portal into another Universe?"

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