At first glance, this image is very similar to the human brain. But in fact, this is one of the earliest scenes in the universe when stars die.
This is an internal simulation of a massive star, “slices”, the quality of the star is about 5.55 times the mass of our sun. The image is displayed inside the helium nuclei burning, helium into oxygen, various types of fluid instabilities driven to form an image of those shown in the scroll structure. This is the time of the freeze, into the outbreak stage show star status after a day, when the star of the outermost boundary has been extended to the equivalent of the Earth’s orbit around the sun’s position today
As the process of stellar collapse, which began rapid synthesis of heavy elements inside, such as oxygen, neon, magnesium and silicon. This process releases a lot of energy, it will eventually reverse the collapse process and lead to a supernova
In order to simulate a primitive supermassive star’s life cycle, Dr. Chen and his colleagues used a stellar evolution code named “KEPLER”‘s. This procedure is considered in the design of some of the key processes of stellar evolution, such as the nuclear burning and stellar convection mechanism, also joined a number of the characteristics of a massive star
Beijing time on October 3, according to the British “Daily Mail” reported that at first glance, this image is very similar to the human brain. But in fact, this is one of the earliest scenes in the universe when stars die.
The researchers said that the death of these early stars are unique, they will occur in the form of a supernova eruption, and completely burned, leaving a black hole, but the large number of chemical substances to sow into space.
Some quality of the original mass of the sun to reach the stars from 55,000 to 5.6 million times, this monster, its manner of death is unusual. After this proposed University of California, Santa Cruz, and University of Minnesota’s astrophysicists at the Federal Department of Energy’s National Energy Research Scientific Computing Center (NERSC) and the Institute of the University of Minnesota Supercomputing conducted several rounds of supercomputer computation a theory.
This work relies heavily on CASTRO package, which is the U.S. Department of Energy’s Lawrence Berkeley National Laboratory Computing Institute (CRD) developed an astrophysics package. The latest study, published recently been published in the “Astrophysical Journal” on.
The first generation of stars, especially scientists who are interested, because they produce the first heavy elements, heavy elements mentioned here refers to all those atomic weight greater than hydrogen and helium elements. When death comes, they put all the heavy elements produced by sprinkling their surrounding space, thereby laying the foundation for the birth of subsequent generations of stars, and even galaxies. By further understanding of these stellar death of the earliest models, scientists hope to better understand this universe we live in today is how to molding.
Chengke Jun (transliteration: Ke-Jung Chen) is a postdoctoral fellow at UCSC, is the first author of the study. He said: “We found that there is a narrow window within which the star can be completely blown up without leaving a black hole, this has never before been such a mechanism has been proposed, but if there is no resource NERSC provided. We may also need a much longer time to get this result, “he said:” From the user’s point of view, very efficient running of this facility is a very convenient place to do science. “
In order to simulate the original star’s life cycle, the study group using a one-dimensional stellar evolution code, called “KEPLER”. This procedure is considered in the design of some of the key processes of stellar evolution, such as the nuclear burning and stellar convection mechanism. Also added for some of the characteristics of massive stars, such as light-induced fission, electronic elements – positron generation and special relativistic effects. Study group also considered the effects of general relativity, which has more than 1000 times the sun for a super star in terms of quality is an important factor that must be considered.
The result is that they find those quality between 55,000 ~ 56,000 solar masses super star life of about 169 years, after which it will start to become unstable at the role of general relativity effects and begin the process of collapse. As the star collapses, its interior began rapid synthesis of heavy elements, such as oxygen, neon, magnesium and silicon, and so on. This process releases a lot of energy, which shares the powerful energy to let the stars keep pressure off the whole existence of gravitational pull, finally resulting in stellar collapse violently interrupted and the outbreak – a supernova appeared.
In order to simulate death mechanisms such massive stars, the study group used CASTRO package, which is a by Berkeley Laboratory Astrophysics Ann Amn Keane (Ann Almgren) and John Bell (John Bell) developed learn special package.
These simulated reality, once the collapse process is reversed, Rayleigh – Taylor instability (Rayleigh-Taylor instabilities) will make all kinds of heavy elements in the final stages of stellar life intermixed.
Study Group said this confounding effect will produce a unique observation signal, the new near-infrared detector will use in the future there can be detected, such as the European Space Agency (ESA) and NASA’s probe of Euclid Wide Area Infrared Survey Telescope.
Depending on the strength of such a supernova, the outbreak can cause part of the supernova near the galaxy and even other galaxies element enrichment, from carbon to silicon, and diverse types of enrichment of heavy elements. In some cases, even supernova explosions can trigger the formation of a large number of newborn stars in the galaxy in which it, so that this galaxy and other galaxies become completely different.
Dr Chan said: “My work is mainly focused on the physics of fluid dynamics beyond the mechanism of supernova explosions of massive stars great research, so I worked with Amn Keane, in many projects over the years and gradually try to adapt Use CASTRO package before I carry out this simulation, I tend to first think about in order to solve a particular problem in physics required. then I will work with Amn Keane, developed a code, and CASTRO its integration into the package, which is a completely different system. “
In order to visualize the data, Dr. Chen uses the open source tool called “VisIt”, which is by former Berkeley Lab scientist Hank Rothschild (Hank Childs) constructed. Chengke Jun said: “Most of the time, I have been running their own visual simulation, but sometimes I need to make some changes, I will send an email to Hank, he was very helpful to me.”
Most of the work of the study is Dr. Chen in the University of Minnesota graduate student during completed. He completed doctoral studies in physics in 2013.