Far out cosmology: our weird black hole (Introduction)

by David Turell , Thursday, March 21, 2024, 16:46 (245 days ago) @ David Turell

Supermassive but quiet:

https://mail.google.com/mail/u/0/#inbox/FMfcgzGxSRGfRtccszfDDBnRbgNTFRph

"...unlike its ferocious cousins in distant galaxies that actively gobble up surrounding material, A* turns out to be a very picky eater.

"And that’s the first reason our black hole is weird: Most of the time, it appears relatively calm, emitting faint radiation and consuming matter at a slow pace. The next reason it’s weird is that while normally very quiet, A* periodically flares up with brief bright infrared and X-ray flares. Just why it does that has so far remained a mystery.

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"A third reason is that in in 2019 Sagittarius A* it surprised astronomers by a sudden increase in activity, pulling in a much larger amount of dust and gas which no one saw coming.

"A fourth observation that adds to the mystery are the G-objects that orbit A*, where the G stands for gas, though astrophysicists now believe they are a mix of gas and dust. The first such object was discovered in 2004 was called G1, followed by G2 in 2012. By now astronomers have seen about a dozen of them.

"They have elongated shapes and peculiar orbits that bring them close to the event horizon and yet some of them survive mostly intact and escape. Their total mass is probably a few to a few dozen times the mass of Earth. However, it’s unclear exactly what they’re made of, where they come from, or how about how they manage to survive for that long the harsh environment so close to the black hole.

"The fifth reason our black hole is weird is its spin. In a paper that just appeared a few months ago, a study from researchers at Penn State used x-ray data from the Chandra Observatory and radio data from the Very Large Array. They found that Sagittarius A* is spinning almost at the theoretical limit, at 60% of what’s possible. You see black holes can’t spin arbitrarily fast because at some point that would exceed the speed of light limit. The 60% is so fast that it significantly pull spacetime with it as it spins. It goes around about once every 10 minutes.

"The sixth and final reason why our black hole is weird is the blob. A team of astrophysicists at the National Autonomous University of Mexico recently discovered a strange object, a blob of gas whipping around the black hole at an astonishing 30% the speed of light!

"They spotted this object by analysing data collected by the Fermi Gamma-ray Space Telescope. This speeding blob releases powerful bursts of gamma rays, a form of high-energy radiation, every 76 minutes. The scientists say that this discovery could be the key to understanding where the strange gamma-ray blasts come from.

Comment: this is not so mysterious if you accept a designer God who put life on Earth and wanted it protected from a dangerous black hole.