Evidence for an aspherical Population III supernova explosion inferred from the hyper metal-poor star HE1327-2326. (arXiv:1904.03211v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Ezzeddine_R/0/1/0/all/0/1">Rana Ezzeddine</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Frebel_A/0/1/0/all/0/1">Anna Frebel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Roederer_I/0/1/0/all/0/1">Ian U. Roederer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tominaga_N/0/1/0/all/0/1">Nozomu Tominaga</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tumlinson_J/0/1/0/all/0/1">Jason Tumlinson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ishigaki_M/0/1/0/all/0/1">Miho Ishigaki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nomoto_K/0/1/0/all/0/1">Ken&#x27;ichi Nomoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Placco_V/0/1/0/all/0/1">Vinicius M. Placco</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aoki_W/0/1/0/all/0/1">Wako Aoki</a>

We present observational evidence that an aspherical supernova explosion
could have occurred in the First stars in the early universe. Our results are
based on the First determination of a Zn abundance in a Hubble Space
Telescope/Cosmic Origins Spectrograph high-resolution UV spectrum of a hyper
metal-poor (HMP) star, HE1327-2326, with [Fe/H](NLTE) = -5.2. We determine
[Zn/Fe] = 0.80$pm$0.25 from a UV Zn I line at 2138 detected at $3.4sigma$.
Yields of a 25M$_{odot}$ aspherical supernova model with artificially modified
densities exploding with E = 5×10$^{51}$ ergs best match the entire abundance
pattern of HE1327-2326. Such high-entropy hypernova explosions are expected to
produce bipolar outfows which could facilitate the external enrichment of small
neighboring galaxies. This has already been predicted by theoretical studies of
the earliest star forming minihalos. Such a scenario would have significant
implications for the chemical enrichment across the early universe as HMP
Carbon Enhanced Metal-Poor (CEMP) stars such as HE1327-2326 might have formed
in such externally enriched environments.

We present observational evidence that an aspherical supernova explosion
could have occurred in the First stars in the early universe. Our results are
based on the First determination of a Zn abundance in a Hubble Space
Telescope/Cosmic Origins Spectrograph high-resolution UV spectrum of a hyper
metal-poor (HMP) star, HE1327-2326, with [Fe/H](NLTE) = -5.2. We determine
[Zn/Fe] = 0.80$pm$0.25 from a UV Zn I line at 2138 detected at $3.4sigma$.
Yields of a 25M$_{odot}$ aspherical supernova model with artificially modified
densities exploding with E = 5×10$^{51}$ ergs best match the entire abundance
pattern of HE1327-2326. Such high-entropy hypernova explosions are expected to
produce bipolar outfows which could facilitate the external enrichment of small
neighboring galaxies. This has already been predicted by theoretical studies of
the earliest star forming minihalos. Such a scenario would have significant
implications for the chemical enrichment across the early universe as HMP
Carbon Enhanced Metal-Poor (CEMP) stars such as HE1327-2326 might have formed
in such externally enriched environments.

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