From KAVLI IPMU: “Supersonic gas streams left over from the Big Bang drive massive black hole formation”

KavliFoundation

The Kavli Foundation

Kavli IPMU
Kavli IMPU

September 29, 2017

Research contacts
Shingo Hirano
JSPS Overseas Research Fellow
Department of Astronomy, University of Texas
shirano@astro.as.utexas.edu

Naoki Yoshida
Principal Investigator
Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo
naoki.yoshida@ipmu.jp

Media Contact
Motoko Kakubayashi
Press Officer
Kavli Institute for the Physics and Mathematics of the Universe,
The University of Tokyo Institutes for Advanced Study,
The University of Tokyo
TEL: +81-04-7136-5980
press@ipmu.jp

1
Figure 1: Projected density distributions of dark matter (background and top panel) and gas (bottom three panels) components when the massive star forms. No image credit.

2
Figure 2: Close up showing gas density distribution around a protostar (centre). The high-speed gas flowing from the top left of the image to the right compresses the central gas cloud, while the yellow to light-green areas show the development of strong turbulence. No image credit.

4
Figure 3: Evolution of the temperature and density structure during the protostellar accretion phase. The rapid accretion of a dense gas cloud (white contour) causes the brightening of the star, and photoionized regions are lauched (red). No image credit.

An international team of researchers has successfully used a super-computer simulation to recreate the formation of a massive black hole from supersonic gas streams left over from the Big Bang. Their study, published in this week’s Science, shows this black hole could be the source of the birth and development of the largest and oldest super-massive black holes recorded in our Universe.

“This is significant progress. The origin of the monstrous black holes has been a long-standing mystery and now we have a solution to it,” said author and Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Principal Investigator Naoki Yoshida.

Recent discoveries of these super-massive black holes located 13 billion light years away, corresponding to when the universe was just five per cent of its present age, pose a serious challenge to the theory of black hole formation and evolution. The physical mechanisms that form black holes and drive their growth are poorly understood.

Theoretical studies have suggested these black holes formed from remnants of the first generation of stars, or from a direct gravitational collapse of a massive primordial gas cloud. However, these theories either have difficulty in forming super-massive black holes fast enough, or require very particular conditions.

Yoshida and JSPS Overseas Research Fellow Shingo Hirano, currently at the University of Texas at Austin, identified a promising physical process through which a massive black hole could form fast enough. The key was incorporating the effect of supersonic gas motions with respect to dark matter. The team’s super-computer simulations showed a massive clump of dark matter had formed when the universe was 100 million years old. Supersonic gas streams generated by the Big Bang were caught by dark matter to form a dense, turbulent gas cloud. Inside, a protostar started to form, and because the surrounding gas provided more than enough material for it to feed on, the star was able to grow extremely big in a short amount of time without releasing a lot of radiation.

“Once reaching the mass of 34,000 times that of our Sun, the star collapsed by its own gravity, leaving a massive black hole. These massive black holes born in the early universe continued to grow and merge together to become a supermassive black hole,” said Yoshida.

The number density of massive black holes is derived to be approximately one per a volume of three billion light-years on a side – remarkably close to the observed number density of supermassive black holes,” said Hirano.

The result from this study will be important for future research into the growth of massive black holes. Especially with the increased number of black hole observations in the far universe that are expected to be made when NASA’s James Webb Space Telescope is launched next year.

This research was published in Science on September 28.

Aterui, one of the supercomputers this work used, is operated by the Center for Computational Astrophysics (CfCA) of the National Astronomical Observatory of Japan (NAOJ).

3
NAOJ ATERUI CRAY XC30 supercomputer

See the full article here .

Please help promote STEM in your local schools.

STEM Icon

Kavli IPMU (Kavli Institute for the Physics and Mathematics of the Universe) is an international research institute with English as its official language. The goal of the institute is to discover the fundamental laws of nature and to understand the Universe from the synergistic perspectives of mathematics, astronomy, and theoretical and experimental physics. The Institute for the Physics and Mathematics of the Universe (IPMU) was established in October 2007 under the World Premier International Research Center Initiative (WPI) of the Ministry of Education, Sports, Science and Technology in Japan with the University of Tokyo as the host institution. IPMU was designated as the first research institute within the University of Tokyo Institutes for Advanced Study (UTIAS) in January 2011. It received an endowment from The Kavli Foundation and was renamed the “Kavli Institute for the Physics and Mathematics of the Universe” in April 2012. Kavli IPMU is located on the Kashiwa campus of the University of Tokyo, and more than half of its full-time scientific members come from outside Japan. http://www.ipmu.jp/
Stem Education Coalition
The Kavli Foundation, based in Oxnard, California, is dedicated to the goals of advancing science for the benefit of humanity and promoting increased public understanding and support for scientists and their work.

The Foundation’s mission is implemented through an international program of research institutes, professorships, and symposia in the fields of astrophysics, nanoscience, neuroscience, and theoretical physics as well as prizes in the fields of astrophysics, nanoscience, and neuroscience.