The first stars were cruel but destitute

The first stars that appear in the universe are likened to the most cruel but destitute monsters. They have forever changed the nature of the universe, dispelling a black mist that makes stuffy space for 300 million years. They have also brought life to our universe.

The information mentioned above is from a computer simulation of the primitive image of the universe published by a group of astronomers announced by Naoki Yoshida of Nagoya University, Japan.

Calculations have shown how small clusters of material and energy distributions can attract more matter by gravity, warming, shrinking, and then becoming the first "cosmic object" . These cosmic objects are called tiny seeds or primitive stars with a mass of 1/100 of the Sun's mass . For about 10,000 years, by absorbing the surrounding gas clouds they probably grew into giant stars, at least 100 times larger than the Sun.

Those stars may have shone brightly then faded away. They only burned for a million years. This means that simulated images on computers are just like telescopes so we can observe stars in their original shape.

Responding to a press conference on Wednesday, Dr. Yoshida said: 'The simulated image that gives the picture a clear picture of how the first stars were formed' . He and his colleagues published their findings in Science issue 6.

Volker Bromm, an astronomer at the University of Texas at Austin, did not participate in the study, saying Dr. Yoshida had obtained a simulated image of the early universe at a new level, although still lots of things to do next. He commented on the paper in the following Science: 'The basic objective of predicting the mass and characteristics of the first stars has been within reach'.

The computer simulation image depicts the universe at 300 million years after the Big Bang.The first stars radiate ionizing radioactive bubbles (green) into the surrounding primitive gas (green).(Photo: PA Navratil, Texas Advanced Computing Center; JL Johnson, TH Greif, V. Bromm, University of Texas at Austin)

Lars Hernquist of Harvard Center for Astrophysics - Smithsonian and member of Dr. Yoshida's group considered the calculation work as an attempt to fill the gap in the universe of knowledge knowledge.

Astronomers have correctly calculated the universe at the time it was 400,000 years old from studying the haze of microwaves left over from the Big Bang, and they knew what the universe is like today. 'This study aims to understand how objects are born in the universe as well as their effects after they appear'.

The presence of the first stars, about 300 million years after the Big Bang, was a major historical event for two reasons. First, soon after the Big Bang fire cooled, the first stars that lit up the universe previously sunk into the night. Thanks to the fusion reaction, they continue to form the metalloid in the universe from two essential components, hydrogen and helium, to today's rich set of heavier elements such as carbon, oxygen, nitrogen and Iron.

Many larger stars burn hotter, faster, and produce more heavy elements than light stars. Therefore the result that Dr. Yoshida obtained means that the process of enriching the universe takes place quickly. Astronomers can test this by observing many of the same elements in the oldest but lightest stars around us.

The massive stars also emit a huge amount of ultraviolet radiation needed to ionize the hydrogen to fill the universe at the same time as the dark mist after cooling down from the Big Bag explosion. Since then, the universe can be seen under ordinary light, at the same time ending the period that cosmologists call "dark era".

Astronomers have long argued that the first stars were very large, because they did not carry any heavy elements. They call these heavy elements metallic. The helium clouds and hydrogen - the original gas - cannot cool down easily. So they compress under the pressure of oncoming materials, they heat up and move backwards. Only when the gas masses are extremely large, then their attraction can exceed the pressure to help the star form.

The first primitive stars started out as tiny seeds, then quickly grew into stars 100 times larger than our Sun.In the image is a cloud of hydrogen gas and helium gas illuminated by the first light from stars in the universe.On the smaller part of the picture is a supernova explosion that releases heavy elements that will one day combine to form new stars and planets.(Photo: Image courtesy of David A. Aguilar (CfA) via Science / AAAS - ScienceDaily)

Astronomers have been using computers for decades to simulate the transformation of cosmic elements when combined together under the force of attraction. But they often have to stop when clumps become hot and dense enough to allow other factors such as radiation, heat and gas dynamics to complicate things. Dr. Yoshida said that his simulation model is the first model that can track the complex interaction of gas and radiation that governs the evolution of primitive stars.

Tien said his computer program 'like an artistic masterpiece' has been developed for 7, 8 years. The simulation was done on a network of 70 processing computers, starting with a cosmic image that looked almost like a smooth mixture of hydrogen, helium and mysterious dark matter - perhaps clouds. carrying chemical elements has not been clearly defined. It is their gravity that forms the distribution of matter in the universe.

Over time, small ripples in dark matter cause the initial material to stir, increasing heat and losing energy due to radiation, then shrinking and forming a stable seed with a density of 1 / 100 of water and has a mass of 1/100 of the Sun. That is all the calculation achieved to this day.

However, the seeds are surrounded by huge amounts of dust and gas, which gradually develop. But to what extent development depends on higher calculations.

Basically, the calculation does not describe the fact that the gas splits into smaller arrays during the original star formation. Dr. Hernquist explained, if matter is separated, the first stars will be closer to the Sun in terms of mass, life history, and the way they disappear. 'This plays an important role to know exactly how massive stars are . ' Since then, astronomers have been able to deduce what might have happened to them. Are they scattered in heaven after a supernova explosion or have they been swept into the black hole?

'Until now, we still don't know how the stars turned off , ' Dr. Hernquist said.