Stories
Slash Boxes
Comments

SoylentNews is people

Seeing Double: Scientists Find Elusive Giant Black Hole Pairs

posted by mrpg on Thursday October 05 2017, @09:06AM   Printer-friendly
from the better-pairs-than-trios dept.

"exec" writes:

Astronomers have identified a bumper crop of dual supermassive black holes in the centers of galaxies. This discovery could help astronomers better understand how giant black holes grow and how they may produce the strongest gravitational wave signals in the Universe.

The new evidence reveals five pairs of supermassive black holes, each containing millions of times the mass of the Sun. These black hole couples formed when two galaxies collided and merged with each other, forcing their supermassive black holes close together.

The black hole pairs were uncovered by combining data from a suite of different observatories including NASA's Chandra X-ray Observatory, the Wide-Field Infrared Sky Explorer Survey (WISE), and the ground-based Large Binocular Telescope in Arizona.

"Astronomers find single supermassive black holes all over the universe," said Shobita Satyapal, from George Mason University in Fairfax, Virginia, who led one of two papers describing these results. "But even though we've predicted they grow rapidly when they are interacting, growing dual supermassive black holes have been difficult to find."

Seeing double: Scientists find elusive giant black hole pairs

-- submitted from IRC

Original Submission

 
This discussion has been archived. No new comments can be posted.
Seeing Double: Scientists Find Elusive Giant Black Hole Pairs | Log In/Create an Account | Top | 14 comments | Search Discussion
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.

  • (Score: 2) by maxwell demon on Friday October 06 2017, @04:08PM (2 children)

    by maxwell demon (1608) on Friday October 06 2017, @04:08PM (#578081) Journal

    Ah, but it isn't just a single displacement. It's running at 35 to 250 Hz, and over a somewhat extended period of time. If every cell in your body was vibrating with an amplitude of 0.1 µm

    Not every cell. The body as a whole. Every cell gets only a tiny fraction of it. Indeed, human cells have sizes in the µm range (a factor of about 10-6 to the total body size), therefore their stretch would be in the range of 0.1 pm (that's a fraction of the size of an atomic nucleus). Doesn't sound deadly, does it?

    What about an earth-sized planet at that distance?

    Ah, changing the goalpost …

    The radius of the earth is around 12742 km,

    You surely mean the diameter. The radius is half of that.

    and with a strain of 10-7, that amounts to a stretch of about 1.2 m. Having that kind of stretching and shrinking continuously for several hours or days at 250 Hz or so kind of sounds like a good way to cause a lot of powerful seismic and volcanic activity.

    Seismic/volcanic activity doesn't care the slightest about the whole-planet deformation; it only cares about the local stresses. Note that the moon also deforms earth about 0.1 meter; that's about 10% of the value you give (though admittedly at a far lower frequency). Now I don't know enough about seismology/geology to tell whether this could trigger some earthquakes; probably it could. But I'm sure it would be much less dramatic than you picture.

    Also note that at that distance, the non-wave gravitational effects (that is, the varying gravitational/tidal forces, varying at the same frequency as the gravitational waves) would already be quite large (remember, we are talking about 30 solar masses), so I'd expect that to be the main problem of a planet at that distance.

    --
    The Tao of math: The numbers you can count are not the real numbers.
    Starting Score:    1  point
    Karma-Bonus Modifier   +1  
    Total Score:   2  

  • (Score: 2) by stormwyrm on Saturday October 07 2017, @01:18AM (1 child)

    by stormwyrm (717) on Saturday October 07 2017, @01:18AM (#578430) Journal
    Well, thanks for the explanations. I still remember a little bit about basic classical and quantum stuff from school but never actually studied general relativity in any serious detail. What about the case of two supermassive black holes inspiralling, say each of them five million solar masses? Might that produce enough gravitational radiation to kickstart a quasar?
    --
    Numquam ponenda est pluralitas sine necessitate.

    • (Score: 2) by maxwell demon on Saturday October 07 2017, @06:28AM

      by maxwell demon (1608) on Saturday October 07 2017, @06:28AM (#578495) Journal

      I have no idea what it takes to kickstart a quasar, but with those masses, you definitely don't want to be anywhere near for sure.

      --
      The Tao of math: The numbers you can count are not the real numbers.