Computer models continue to play an increasing role in scientific discovery. Everything from the first moments after the Big Bang to the potential for life to form on other planets was the target of some kind of computer model. Now scientists at the RIKEN Astrophysical Big Bang Laboratory are turning this almost ubiquitous tool into a very violent event – Type Ia supernovae. Your work has now led to a more nuanced understanding of the effects of these important events.
Type Ia supernovae are types of supernovae that occur in binary star systems – especially in systems with a white dwarf star. Eventually, the white dwarf will run out of fuel to power its nuclear reaction. In some cases, however, matter from the companion star can restart the reactions of the white dwarf, which can then lead to a runaway nuclear fusion event, resulting in a Type Ia supernova, creating all naturally occurring heavy elements with atomic weights greater than are iron.
When the white dwarf explodes, it creates a shock wave known as the remnant. These remains are known to vary along with the explosion that caused them, but it wasn’t really clear how or why.
This is where computer simulation comes in. The RIKEN team, led by physicist Gilles Ferrand, developed two different models – one to model the supernova explosion itself and one to model the rest.
Spectacular example of a supernova remnant.
Photo credit: NASA
There were two main variables that the RIKEN team wanted to control as part of the explosion model. The first was how exactly the runaway reaction that caused the supernova is ignited. The second was how this explosion spreads through the collapsing star.
The results of the various models created using this method were then fed into the simulation of the supernova remnant. Dr. Ferrand and his team found that there were four main categories into which the remains could be classified based on some variable details of the actual explosion that produced them.
The first was the number of points at which the supernova explosion begins. The two main categories for this variable are that the explosion would either begin in a few, different locations or in multiple locations throughout the star at once.
The second variable deals with a concept known as deflagration, which is defined as “turbulent fire moving slower than the speed of sound”. Alternatively, these deflagrations can occasionally lead to an extremely rapid detonation. Deflagration fires are caused by the explosions that set off the supernova, but the speed at which they move could have a profound effect on the rest.
Supernova G292.0 + 1.8. Like most supernovae, it detonated in a host galaxy – ours, in fact. Photo credit: Chandra.
By combining all of these variables into a complete remnant model, researchers can define four different types of remains that result from four different types of explosions. Since debris can still be seen hundreds of years after the supernova that created it, it might be particularly useful to understand its shape and then go back to the type of supernova that caused it in the first place, to the frequency of different types of Understand star explosions.
One day there might even be a computer model that can predict exactly what kind of residue will be produced by a particular supernova before it’s even visible. Sounds like a good rework for Dr. Ferrand and his team.
Learn more:
RIKEN – Supernova simulations show how star explosions form clouds of debris
UT – The solar system has been flying through the debris of a supernova for 33,000 years
UT – A new supernova remnant found by an exploding white dwarf star
Mission statement:
Artist’s impression of a supernova remnant growing out of the original explosion as it is formed by it.
Photo credit: Ferrand et al., American Astronomical Society permission
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