Black Holes Surrounded by Gaseous ‘Fountains,’ Not ‘Donuts’

By Chelsea Gohd | December 4, 2018 4:39 pm
The distributions of CO molecular gas and C atomic gas are shown in orange and cyan, respectively. (Credit: ALMA (ESO/NAOJ/NRAO), Izumi et al.)

CO molecular gas and C atomic gas distribute around a black hole, as shown in orange and cyan, respectively. (Credit: ALMA (ESO/NAOJ/NRAO), Izumi et al.)

Black Hole Fountains

Where once were donuts, now there may be fountains. Not literally, unfortunately, but new astronomical observations are rewriting scientists’ conceptions of what the area around a black hole looks like, and the new evidence seems to lean heavily away from the morning delicacy.

Scientists estimate that most galaxies have a supermassive black hole at their center, pulling in everything around them with tremendous gravitational forces. Up until now, astronomers believed that before material falls into a black hole it builds up into a structure that looks something like a cosmic donut.

Takuma Izumi, a researcher at the National Astronomical Observatory of Japan (NAOJ), led a team of astronomers that used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe the supermassive black hole at the center of the Circinus Galaxy 14 million light-years from Earth. And, in their research they found that the material surrounding black holes actually looks much different.

Comparing the Cosmos

The team compared their observations with a computer simulation they created that simulated gas falling towards a black hole. When they compared their observations with the simulation, they found that what astronomers had previously thought was a rigid “donut” structure around black holes wasn’t actually solid at all. They instead found a dynamic circular pattern of gas that resembled a water fountain.

This “fountain” is created when cold gas falls towards the black hole and form a disk. As the gas gets closer to the black hole, it starts to heat up and break apart into individual molecules and then atoms and ions. Some of these hot atoms are absorbed by the black hole, but some shoot out above the disk and some shoot out below. These atoms then fall back onto the disk, creating a three-dimensional structure that continuously circulates the molecules and atoms of hot gas. The best terrestrial analogue is probably the water fountain in your city park.

“By investigating the motion and distribution of both the cold molecular gas and warm atomic gas with ALMA, we demonstrated the origin of the so-called ‘donut’ structure around active black holes. Based on this discovery, we need to rewrite the astronomy textbooks,” Izumi added in a statement.

The finding completely alters what some once considered to be astronomical fact. Still, it’s the first time researchers have suggested that these donuts are actually fountains, so the claim is likely to face further scrutiny.

This work is published in The Astrophysical Journal. 

CATEGORIZED UNDER: Space & Physics, top posts
  • Uncle Al

    Donuts, fountains; up or down…vortex ring.

    • OWilson

      Vortex ring, now THAT’S the thing!

      The secret of the universe, from DNA, plants, shells, kitchen sinks to black holes, galaxies and beyond. Spirals.

      Sadly missing only from the BB Theory!

      • harmonograms

        Generally, when galaxies collide, they settle into the form of a spiral galaxy, which evolves into a barred spiral galaxy, and if no further galactic collisions occur, a circular ring galaxy (like Hoag’s object) is eventually formed. Each new galactic collision/merger starts the cycle over and adds a pair of arms to the spiral galaxy. This galactic evolutionary transition can be demonstrated with a 1:1 ratio two-pendulum harmongraph gravity powered physics toy. The universe is incomprehensibly simple.

        • OWilson

          Indeed it was simple, until the observations by Rubin et al (1980) presented us with the “flat rotation problem”. She showed that:

          “most stars in spiral galaxies orbit at roughly the same speed,[14] and that this implied that galaxy masses grow approximately linearly with radius well beyond the location of most of the stars (the galactic bulge).

          These results suggested that either Newtonian gravity does not apply universally or that, conservatively, upwards of 50% of the mass of galaxies was contained in the relatively dark galactic halo. Although initially met with skepticism, Rubin’s results have been confirmed over the subsequent decades.[16]

          If Newtonian mechanics is assumed to be correct, it would follow that most of the mass of the galaxy had to be in the galactic bulge near the center and that the stars and gas in the disk portion should orbit the center at decreasing velocities with radial distance from the galactic center.

          Observations of the rotation curve of spirals, however, do not bear this out. Rather, the curves do not decrease in the expected inverse square root relationship but are “flat”, i.e. outside of the central bulge the speed is nearly a constant (the solid line in Fig. 1). It is also observed that galaxies with a uniform distribution of luminous matter have a rotation curve that rises from the center to the edge, and most low-surface-brightness galaxies (LSB galaxies) have the same anomalous rotation curve.

          The (anomalous) rotation curves might be explained by hypothesizing the existence of a substantial amount of matter permeating the galaxy that is not emitting light in the mass-to-light ratio of the central bulge. The material responsible for the extra mass was dubbed “dark matter”,

          The existence of non-baryonic cold dark matter (CDM) is today a major feature of the Lambda-CDM model that describes the cosmology of the universe.” -Wiki

          If the rotation curves of galaxies are indeed flat, like a spinning physical disk, there appears to be no mechanism for the classical whirlpool spiral we see, or indeed, any “galactic evolution”.

          Enter, Dark Matter!


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