NASA Uncovers Millions of New Black Holes 77
coondoggie writes "NASA today said its Wide-field Infrared Survey Explorer satellite has unearthed a 'bonanza of new-found supermassive black holes and extreme galaxies called hot DOGs, or dust-obscured galaxies.' NASA said the latest discoveries help astronomers better understand how galaxies and the behemoth black holes at their centers grow and evolve together."
The news was released in a press conference, and io9 has a comprehensive write-up about everything that was covered, including the Q&A session. Pretty pictures here.
Re:I know what you're thinking.. (Score:5, Informative)
A black hole would dissipate via Hawking radiation only if it doesn't absorb more energy than it emits. Large blackholes absorb more energy (cosmic background radiation) than they would emit and hence will not necessarily dissipate. From wikipedia [wikipedia.org]:
"A black hole of one solar mass has a temperature of only 60 nanokelvins; in fact, such a black hole would absorb far more cosmic microwave background radiation than it emits. A black hole of 4.5 × 1022 kg (about the mass of the Moon) would be in equilibrium at 2.7 kelvin, absorbing as much radiation as it emits. Yet smaller primordial black holes would emit more than they absorb, and thereby lose mass."
Re:I know what you're thinking.. (Score:5, Informative)
In the long term -- "long" that makes the current age of the universe look like an eye-blink and protons seem unstable -- the CMB will be redshifted away until even supermassive black holes begin losing mass.
"This, too, shall pass."
Re:Missing mass of the universe? (Score:5, Informative)
How does it jibe for balancing things without using 'dark matter/energy'?
Not well.
These SMBHs are in the centers of galaxies, and piling up more mass at the center of a galaxy doesn't explain the problem of flat galactic rotation curves. The mass needs to be in and surrounding the galaxy, which is why the non-exotic DM theory is called "MACHOs" as in MAssive Compact Halo Objects -- because it'd have to be in the halo.
It's even worse for Dark Energy, since extra mass would actually have the opposite effect that DE has, pushing the universe closer to the Big Crunch scenario. It certainly would not explain accelerating expansion.
Re:Holly knows why it took so long to find them... (Score:4, Informative)
They can be found in a number of ways...
They give off something called Bekenstein-Hawking radiation because they are sucking up half of spontaneously generated particle pairs - leaving the other half (that would normally disappear back into the sucked up particle) to spray out into space.
They can be 'seen' by the gravitational lensing they produce when you try to look at the background behind them. (And most of space isn't black, it's full of bright objects and lots of microwave radiation.)