Galaxy Punches Through Neighbor to Spawn Giant Ring of Black Holes
A giant ring of black holes has been discovered 300 million light-years away, offering new clues about what happens when galaxies collide. [...] The observed ring of black holes or neutron stars is believed to be the result of a galaxy collision. The galaxies were likely drawn together by gravity, and the gravitational force from one galaxy created waves in the gas surrounding its neighbor, which, in this case, is AM 0644. The ripples would have then caused the gas to expand or clump together in denser areas, triggering the birth of new stars.
"The most massive of these fledgling stars will lead short lives — in cosmic terms — of millions of years," representatives from the Chandra X-ray Observatory said in a statement. "After that, their nuclear fuel is spent, and the stars explode as supernovas, leaving behind either black holes with masses typically between about five to twenty times that of the sun, or neutron stars with a mass approximately equal to that of the sun." The black holes or neutron stars have close cosmic companions from which they siphon gas. This gas falls inward and is heated by friction, creating the bright X-rays detected by Chandra, according to the statement.
Also at Bad Astronomy.
(Score: 3, Informative) by RS3 on Wednesday September 12 2018, @02:49PM
https://www.google.com/search?q=pressure++event+horizon [google.com]
And if you're feeling much too happy, read this: https://arxiv.org/pdf/1202.4995.pdf [arxiv.org], plug in some numbers, use MatLab / MathCad / Maple / whatever your favorite math software or grind it out like the ancients did. We'll wait for the results... :-}
Since there's potentially much we still don't know about the interior of a star, let alone a black hole, here's some generally accepted stuff: http://burro.case.edu/Academics/Astr221/StarPhys/estcent.html [case.edu]
At the sun'c core, the pressure is estimated at 3.4 x 10^11 ATM.
Here are some more interesting facts, but they don't give all the good numbers: http://www.smartconversion.com/otherInfo/Surface_pressure_of_planets_and_the_sun.aspx [smartconversion.com] and don't take the sun's surface pressure too seriously because most references put it at 10^-4 ATM.
And if you want to see how stunningly advanced science was 95 years ago, http://adsabs.harvard.edu/full/1924ApJ....59..197R [harvard.edu]