Tuesday, September 29, 2020

Sooooooooo BIG!

Environmental & Science Education, STEM, Earth Science, Cosmology, Astronomy

Ed Hessler

"Mindboggling!" is how astronomers announced the detection of the most powerful and distant black-hole collision to date. It was detected May 21, 2019 and is named GW190521 after its detection date.

Writing for the journal Nature, Davide Castelvecchi not only gives us a sense of scale but also one of the surprising findings. "Of the two behemoths that fused when the Universe was half its current age, at least one — weighing 85 times as much as the Sun — has a mass that was thought to be too large to be involved in such an event. And the merger produced a black hole of nearly 150 solar masses, the researchers have estimated, putting it in a range where no black holes had ever been conclusively seen before."

Over at ars technica, science journalist Jennifer Ouellette uses her impressive reporting skills to provide some of the details. Her report includes a short video (30 s) of the numerical simulation of a heavy-black-hole merger, how hunting and finding such mergers are done, a wonderfully informative graphic showing masses in the stellar graveyard (in solar masses), the GW event as it was observed and recorded by the three detectors involved, an artist's conception of merging black holes, an artistic rendering (not a numerical simulation) of a black hole that was once considered too large to happen--a 1m 47 s video, and comments on what's next for the collaboration that announced this finding. Ms. Ouellette writes "LIGO-Virgo scientists have identified 56 possible gravitational wave detections (candidate events) from the now-completed third run, only four of which have been confirmed and publicly announced (including today's announcement). Analysis of the remaining 52 candidates is ongoing, so it's possible the collaboration will announce more discoveries in the future. Any additional discoveries should help shed more light on the many questions raised by GW190521." Is it the first representative of a "new class of binary black holes" or the "high mass end" of what has been observed so far?

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