Supernovae of Early Supermassive Stars

Most galaxies that we have observed contain at their centers a supermassive black hole. While scientists don’t know how these black holes were formed, they have surmised that they could be the remnants of supermassive stars that, at the end of their lives, collapsed to create the black holes. Researchers use computer modeling to study this process.

Recently, Dr. Ke-Jung (Ken) Chen, a former graduate student in the MSI research group of Associate Professor Alexander Heger (Physics and Astronomy, College of Science and Engineering), and his colleagues discovered that there seems to be a narrow range of mass where a supermassive star ends as a supernova instead of collapsing into a black hole. These stars are between 55,000 and 56,000 solar masses (one solar mass equals the mass of our sun). This is an exciting new development, since the supernovae may have resulted in the creation and dispersion of heavy elements (elements other than hydrogen and helium) throughout the cosmos. These elements would be the foundation of next generations of stars and be the basis of the composition of the current universe. Using advanced computer models, the researchers modeled how the stars behaved at the end of their lifespans.

Much of this work was completed while Dr. Chen was a graduate student using MSI resources. Other modeling was completed using resources at the National Energy Research Scientific Computing Center. The article can be read on the Astrophysical Journal website (KJ Chen, A Heger, S Woosley, A Almgren, DJ Whalen, JL Johnson. 2014. The general relativistic instability supernova of a supermassive population III starAstrophysical Journal 790 (2) (AUG 1), 10.1088/0004-637X/790/2/162).

Dr. Chen is currently a post-doc at the University of California Santa Cruz. He was an active user of MSI while he was a grad student at the U. He was a finalist at the 2010 MSI Research Exhibition poster competition and was the Grand Prize winner at the 2011 competition. He was also awarded the 2013 Gruber Foundation Fellowship of the International Astronomical Union. Dr. Chen would especially like to recognize the support of the University of Minnesota’s School of Physics and Astronomy, headed by Professor Ron Poling and Professor Joe Kapusta, and the Minnesota Supercomputing Institute, headed by Professor Tom Jones (2008-10) and Professor Jorge Vinals (2010-present). The project was supported by the DOE SciDAC program under grants DOE-FC02-01ER41176, DOE-FC02-06ER41438, and DE-FC02-09ER41618, and by the US Department of Energy under grant DE-FG02-87ER40328.

Image description: Mixing in 16O, 24Mg, 28Si, and 32S prior to shock breakout. Image and description, KJ Chen et al., Astrophysical Journal, 2014, 10.1088/0004-637X/790/2/162. © 2014, The American Astronomical Society.

posted on December 10, 2014

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