Cosmic observers have recently revealed the most massive binary black hole system ever observed, situated in the elliptical galaxy B2 0402+379, according to a study published in The Astrophysical Journal. These astoundingly massive black holes together have a combined mass that is 28 billion times that of our sun, setting a new record for the greatest binary black hole mass observed to date.
Nestled relatively close together — just 24 light-years apart — these two supermassive black holes present an intriguing cosmic puzzle. Even though theoretically, black holes in such close proximity should merge, this binary pair appears to have been in a persisting orbital dance lasting over 3 billion years. Scientists hypothesized that the incredible mass of these black holes might be a factor inhibiting their merger.
In an attempt to solve this celestial mystery, researchers utilized data from the Gemini North telescope in Hawaii. “The excellent sensitivity of GMOS allowed us to map the stars’ increasing velocities as one looks closer to the galaxy’s center,” said Roger Romani, a Stanford University physics professor and a member of the team that conducted the study.
The host elliptical galaxy, B2 0402+379, is classified as a “fossil cluster”, formed by the mergers of numerous smaller galaxies, and carries a legacy of multiple major mergers. With every such merger, the central black hole mass increased, eventually leading to the formation of the dual supermassive black holes observed today.
However, as the black holes lost energy in the binary system due to interactions with the surrounding stars, the system’s orbit slowed down, bringing the black holes closer. As this process was underway, the energy drained from the binary system also propelled the surrounding stars and gas, depleting the reservoir of matter in close proximity. Without sufficient mass nearby to leach energy from the binary, the expected progression of these black holes towards a merger has reached a standstill.
This research has provided an essential context to the formation of supermassive black hole binaries post-galactic mergers and supports the idea that the mass of such binaries plays a crucial role in stalling them from combining.
While it remains uncertain whether these black holes will surpass this halt and merge eventually or remain suspended in their orbital dance, continued research may shed light on this enigma. “We’re looking forward to follow-up investigations of B2 0402+379’s core where we’ll look at how much gas is present,” says Tirth Surti, lead author of the paper, and a Stanford undergraduate. This upcoming research might provide more insight into whether these black holes will eventually merge or remain a supermassive binary system.
Information Box:
– B2 0402+379 is the host galaxy of this supermassive binary black hole system.
– These black holes are separated by a distance of just 24 light years.
– The sum mass of these black holes is 28 billion times that of the sun.
– This system has been in its current orbital state for over 3 billion years.
– The potential merger of this pair might occur over timescales of millions of years or not at all.
References:
1: Robert Lea, Space.com
2: “The Central Kinematics and Black Hole Mass of 4C+37.11”, The Astrophysical Journal
3: Association of Universities for Research in Astronomy (AURA), Scitechdaily.com