After a long, eight-day leap week, I’m using my weekend to work on my science writer’s style guide manuscript, “How to Effectively Split an Infinitive.”
What’s twice as massive as a supermassive black hole? A gravitationally bound pair of supermassive black holes. Researchers using the Gemini North telescope in Hawai’i analyzed a black hole binary in elliptical galaxy B2 0402+379 to figure out why supermassive black holes take so long to merge.
This particular pair is separated by 24 light-years, which is a razor-thin distance given their enormous mass, but they’ve been circling each other for the last 3 billion years without sealing the deal. Archival data from Gemini North’s Gemini Multi-Object Spectrograph revealed the speed of the stars in the vicinity of the black holes, providing an inference of the mass of the black hole binary—about 28 billion times the size of the sun, the heaviest black holes ever measured.
This supports an existing theory that mass has an inhibitory role in black hole mergers. So why won’t they just get a room already? The study provides evidence that the host galaxy was a merger of one or more older galaxies; following a merger, supermassive black holes slingshot past each other and are slowed in their mutual orbit by the transfer of energy to surrounding stars until they approach closely in a tight orbit.
However, it seems that these two black holes flung so much matter away in the process that there isn’t enough remaining to slow their velocity further, inhibiting their merger in the final stages, like Rachel and Ross on “Friends.”
2024-03-04 02:00:04
Article from phys.org
