21 Feb 2024

• Astronomers have discovered a giant eruption from a supermassive black hole in a cluster of galaxies.
• Some of the gas sent gas away from the black hole by the eruption eventually cooled enough to form numerous clusters of stars.
• Today astronomers see 19 distinct star clusters that may be connected to this event some 200 million years earlier in the cluster’s history.
• Researchers used NASA’s Chandra X-ray Observatory, the LOFAR radio network and other telescopes to make this discovery.

Astronomers have discovered one of the most powerful eruptions from a black hole ever recorded in the system known as SDSS J1531+3414 (SDSS J1531 for short). As explained in our press release, this mega-explosion billions of years ago may help explain the formation of a striking pattern of star clusters around two massive galaxies, resembling “beads on a string.”

SDSS J1531 is a massive galaxy cluster containing hundreds of individual galaxies and huge reservoirs of hot gas and dark matter. At the center of SDSS J1531, which is located about 3.8 billion light-years away, two of the cluster’s largest galaxies are colliding with each other.

Astronomers used several telescopes to study SDSS J1531 including NASA’s Chandra X-ray Observatory, and the Low Frequency Array (LOFAR), a radio telescope. This composite image shows SDSS J1531 in X-rays from Chandra (blue and purple) that have been combined with radio data from LOFAR (dark pink) as well as an optical image from the Hubble Space Telescope (appearing as yellow and white). The inset gives a close-in view of the center of SDSS J1531 in optical light, showing the two large galaxies and a set of 19 large clusters of stars, called superclusters, stretching across the middle. The image shows these star clusters are arranged in an ‘S’ formation that resembles beads on a string.

The multiwavelength data provides signs of an ancient, titanic eruption in SDSS J1531, which a team of researchers think was responsible for creation of the 19 star clusters. Their argument is that an extremely powerful jet from the supermassive black holes in the center of one of the large galaxies pushed the surrounding hot gas away from the black hole, creating a gigantic cavity. The evidence for a cavity comes from “wings” of bright X-ray emission, seen with Chandra, tracing dense gas near the center of SDSS J1531. These wings are the edge of the cavity and the less dense gas in between is part of the cavity. LOFAR shows radio waves from the remains of the jet’s energetic particles filling in the giant cavity. These features are highlighted in a labeled version of the image.

The astronomers also discovered cold and warm gas located near the opening of the cavity, detected with the Atacama Large Millimeter and submillimeter Array (ALMA) and the Gemini North Telescope, respectively. A separate graphic shows the optical image with the cold gas added in green (left), and the warm gas added in red (right). The team argues that some of the hot gas pushed away from the black hole eventually cooled to form the cold and warm gas shown. The team thinks tidal effects from the two merging galaxies compressed the gas along curved paths, leading to the star clusters forming in the “beads on a string” pattern.

Visual Description:

This is an image of a cluster of galaxies called SDSS J1531+3414 in X-ray, optical, and radio light. The overall scene resembles a colorful display of lights as if viewed through a wet, glass window.

Blurry orange dots of different sizes are scattered across a black background. These orange dots are entire galaxies. Near the center of the image, two central galaxies appear as bright, white dots. Star clusters, resembling beads on a string in shades of electric blue, sweep over the galaxy on the left, through the space in between the galaxy pair, and then lightly coil beneath both galaxies. Clouds of blue, X-ray light, and dark pink, radio light, surround the two galaxies.

The blue cloud spreads out for thousands of light-years toward the region above the central galaxies. The dark pink cloud, somewhat resembling the shape of an upside down spinning top toy, stretches far below the two galaxies and slightly toward our left. This dark pink cloud represents the remains of a powerful jet, produced by a supermassive black hole within one of the two central galaxies. In the upper right corner of the image, another dark pink cloud is present. This cloud may be the relic of a counter-jet from the same black hole outburst.

[Image]

(A) View Wavelengths: X-ray

(B) View Wavelengths: Optical   

(C) View Wavelengths: Radio

(D) View Wavelengths: Composite

(E) Multiwavelength Image of SDSS J1531, Labeled 

(F) Cold and warm gas located near the opening of the cavity.