Suzaku finds common chemical makeup at largest cosmic scales

October 26, 2015

A new survey of hot, X-ray-emitting gas in the Virgo galaxy cluster shows that the elements needed to make stars, planets and people were evenly distributed across millions of light-years early in cosmic history, more than 10 billion years ago.

The Virgo cluster, located about 54 million light-years away, is the nearest galaxy cluster and the second brightest in X-rays. The cluster is home to more than 2,000 galaxies, and the space between them is filled with a diffuse gas so hot it glows in X-rays.

Using Japan's Suzaku X-ray satellite, a team led by Aurora Simionescu, an astrophysicist at the Japan Aerospace Exploration Agency (JAXA) in Sagamihara, acquired observations of the cluster along four arms extending up to 5 million light-years from its center.

"Heavier chemical elements from carbon on up are produced and distributed into interstellar space by stars that explode as supernovae at the ends of their lifetimes," Simionescu said. This chemical dispersal continues at progressively larger scales through other mechanisms, such as galactic outflows, interactions and mergers with neighboring galaxies, and stripping caused by a galaxy's motion through the hot gas filling galaxy clusters.

Supernovae fall into two broad classes. Stars born with more than about eight times the sun's mass collapse under their own weight and explode as core-collapse supernovae. White dwarf stars may become unstable due to interactions with a nearby star and explode as so-called Type Ia supernovae.

These different classes of supernovae produce different chemical compositions. Core-collapse supernovae mostly scatter elements ranging from oxygen to silicon, while white dwarf explosions release predominantly heavier elements, such as iron and nickel. Surveying the distribution of these elements over a vast volume of space, such as a galaxy cluster, helps astronomers reconstruct how, when, and where they were produced. Once the chemical elements made by supernovae are scattered and mixed into interstellar space, they become incorporated into later generations of stars.

The overall composition of a large volume of space depends on the mix of supernova types contributing to it. For example, accounting for the overall chemical makeup of the sun and solar system requires a mix of roughly one Type Ia supernova for every five core-collapse explosions.

"One way to think about this is that we're looking for the supernova recipe that produced the chemical makeup we see on much larger scales, and comparing it with the recipe for our own sun," said co-author Norbert Werner, a researcher at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) at Stanford University in California.

In an earlier study led by Werner, Suzaku data showed that iron was distributed uniformly throughout the Perseus Galaxy Cluster, but information about lighter elements mainly produced by core-collapse supernovae was unavailable. The Virgo Cluster observations supply the missing ingredients. Reporting their findings in the Oct. 1 issue of The Astrophysical Journal Letters, Simionescu and her colleagues show they detect iron, magnesium, silicon and sulfur all the way across a galaxy cluster for the first time. The elemental ratios are constant throughout the entire volume of the cluster and roughly consistent with the composition of the sun and most of the stars in our own galaxy.

Because galaxy clusters cover enormous volumes of space, astronomers can use one example to extrapolate the average chemical content of the universe. The study shows that the chemical elements in the cosmos are well mixed, showing little variation on the largest scales. The same ratio of supernova types -- the same recipe -- thought to be responsible for the solar system's makeup was at work throughout the universe. This likely happened when the universe was between 2 and 4 billion years old, a period when stars were being formed at the fastest rate in cosmic history.

"This means that elements so important to life on Earth are available, on average, in similar relative proportions throughout the bulk of the universe," explained Simionescu. "In other words, the chemical requirements for life are common throughout the cosmos."

Launched on July 10, 2005, Suzaku was developed at the Institute of Space and Astronautical Science (ISAS) in Japan, which is part of JAXA, in collaboration with NASA and other Japanese and U.S. institutions. NASA's Goddard Space Flight Center in Greenbelt, Maryland, supplied Suzaku's X-ray telescopes and data-processing software, and operated a facility supporting U.S. astronomers who used the satellite.

Suzaku operated for 10 years -- five times its target lifespan -- to become the longest-functioning Japanese X-ray observatory. On Aug. 26, JAXA announced the end of the mission due to the deteriorating health of the spacecraft.

"Suzaku provided us with a decade of revolutionary measurements," said Robert Petre, chief of Goddard's X-ray Astrophysics Laboratory. "We're building on that legacy right now with its successor, ASTRO-H, Japan's sixth X-ray astronomy satellite, and we're working toward its launch in 2016."

NASA/Goddard Space Flight Center

Related Supernovae Articles from Brightsurf:

FSU-led research team discovers unique supernova explosion
A 7-member international research team led by Florida State University Assistant Professor of Physics Eric Hsiao discovered a supernova that could help uncover the origins of the group of supernovae this star belongs to.

Discovery lays blame on supernova for extinction event nearly 360 million years ago
Between a decline in biodiversity and a series of extinction events, the Late Devonian period was not the most hospitable time on Earth.

New insights about the brightest explosions in the Universe
Swedish and Japanese researchers have, after ten years, found an explanation to the peculiar emission lines seen in one of the brightest supernovae ever observed -- SN 2006gy.

New study sheds light on conditions that trigger supernovae explosions
For the first time, researchers were able to demonstrate the process of detonation formation using both experiments and numerical simulations carried out on supercomputers.

Scientists observe year-long plateaus in decline of type Ia supernova light curves
A team of scientists, including a researcher from Queen's University Belfast, have discovered that the fading of infrared light following Type Ia supernovae explosions can be interrupted, with brightness staying the same for up to a year.

Hubble sets sights on an explosive galaxy
When massive stars die at the end of their short lives, they light up the cosmos with bright, explosive bursts of light and material known as supernovae.

Subaru Telescope captures 1800 exploding stars
The Subaru Telescope has captured images of more than 1800 exploding stars in the Universe, some located 8 billion light years from Earth.

Researchers wonder if ancient supernovae prompted human ancestors to walk upright
Supernovae bombarded Earth with cosmic energy starting as many as 8 million years ago, with a peak some 2.6 million years ago, initiating an avalanche of electrons in the lower atmosphere and setting off a chain of events that feasibly ended with bipedal hominins.

Stars exploding as supernovae lose their mass to companion stars during their lives
Stars over eight times more massive than the sun end their lives in supernovae explosions.

Zwicky Transient Facility spots a bumper crop of supernovae, black holes and more
The Zwicky Transient Facility (ZTF), an automated sky survey project based at Caltech's Palomar Observatory near San Diego, California, has produced its first bounty of new results.

Read More: Supernovae News and Supernovae Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to