Feel The Beat: Black Hole’s Pulse Reveals Its Mysterious Size

by Elizabeth Howell on August 19, 2014

There’s a bit of a mystery buried in the heart of the Cigar Galaxy, known more formally as M82 or Messier 82. Shining brightly in X-rays is a black hole (called M82 X-1) that straddles an unusual line between small and huge black holes, new research has revealed.

The new study reveals for the first time just how big this black hole is — about 400 times the mass of the sun — after about a decade of struggling to figure this out.

“Between the two extremes of stellar and supermassive black holes, it’s a real desert, with only about half a dozen objects whose inferred masses place them in the middle ground,” stated Tod Strohmayer, an astrophysicist at NASA’s Goddard Space Flight Center in Maryland.

Scientists figured this out by looking at changes in brightness in X-rays, which fluctuate according to how gas behaves as it falls towards a black hole. At the event horizon — that spot where you’re doomed, even if you’re light — is where the fluctuation happen most frequently. In general, larger black holes have these fluctuations less frequently, but they weren’t sure if this would apply to something that is of M82 X-1’s size.

A view of the core of Messier 82 (M82), also known as the Cigar Galaxy. Credit: ESA/Hubble & NASA

A view of the core of Messier 82 (M82), also known as the Cigar Galaxy. Credit: ESA/Hubble & NASA

But by going through old data from NASA’s Rossi X-ray Timing Explorer (RXTE) satellite — which ceased operations in 2012 — the scientists uncovered a similar pulsing relationship to what you see in larger black holes.

Specifically, they saw X-ray variations repeating 5.1 and 3.3 times a second, which is a similar 3:2 ratio to other black holes studied. This allows them to extend the measurement scale to this black hole, NASA stated.

Results of the study were published this week in Nature. The research was led by Dheeraj Pasham, a graduate student at the University of Maryland, College Park.

Source: NASA

About 

Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.

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