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Post Info TOPIC: Pair-instability supernova
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Title: Finding the First Cosmic Explosions. IV. 90 - 140 solar mass Pair-Instability Supernovae
Author: Joseph Smidt, Daniel J. Whalen, E. Chatzopoulos, Brandon K. Wiggins, Ke-Jung Chen, Alexandra Kozyreva, Wesley Even

Population III stars that die as pair-instability supernovae are usually thought to fall in the mass range of 140 - 260 solar masses. But several lines of work have now shown that rotation can build up the He cores needed to encounter the pair instability at stellar masses as low as 90 solar masses. Depending on the slope of the initial mass function of Population III stars, there could be 4 - 5 times as many stars from 90 - 140 solar masses in the primordial universe than in the usually accepted range. We present numerical simulations of the pair-instability explosions of such stars performed with the MESA, FLASH and RAGE codes. We find that they will be visible to supernova factories such as Pan-STARRS and LSST in the optical out to z ~ 1 - 2 and to JWST and the 30 m-class telescopes in the NIR out to z~ 7 - 10. Such explosions will thus probe the stellar populations of the first galaxies and cosmic star formation rates in the era of cosmological reionisation. These supernovae are also easily distinguished from more massive pair-instability explosions, underscoring the fact that there is far greater variety to the light curves of these events than previously understood.

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Blobrana


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Title: Finding the First Cosmic Explosions I: Pair-Instability Supernovae
Authors: Daniel J. Whalen, Wesley Even, Lucille H. Frey, Jarrett L. Johnson, C. C. Lovekin, Chris L. Fryer, Massimo Stiavelli, Daniel E. Holz, Alexander Heger, S. E. Woosley, Aimee L. Hungerford

The first stars are the key to the formation of primitive galaxies, early cosmological reionisation and chemical enrichment, and the origin of supermassive black holes. Unfortunately, in spite of their extreme luminosities, individual Population III stars will likely remain beyond the reach of direct observation for decades to come. However, their properties could be revealed by their supernova explosions, which may soon be detected by a new generation of NIR observatories such as JWST and WFIRST. We present light curves and spectra for Pop III pair-instability supernovae calculated with the Los Alamos radiation hydrodynamics code RAGE. Our numerical simulations account for the interaction of the blast with realistic circumstellar envelopes, the opacity of the envelope, and Lyman absorption by the neutral IGM at high redshift, all of which are crucial to computing the NIR signatures of the first cosmic explosions. We find that JWST will detect pair-instability supernovae out to z > 30, WFIRST will detect them in all-sky surveys out to z ~ 15 - 20 and LSST and Pan-STARRS will find them at z ~ 7 - 8. The discovery of these ancient explosions will probe the first stellar populations and reveal the existence of primitive galaxies that might not otherwise have been detected.

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Blobrana


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A pair-instability supernova occurs when pair production, the production of free electrons and positrons in the collision between atomic nuclei and energetic gamma rays, reduces thermal pressure inside a supermassive star's core. This pressure drop leads to a partial collapse, then greatly accelerated burning in a runaway thermonuclear explosion which blows the star completely apart without leaving a black hole remnant behind.
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