Paper

{
  "raw_xml": "<entry>\n    <id>http://arxiv.org/abs/2603.14939v1</id>\n    <title>Probing the first generations of massive stars through fluorine in CEMP-no stars</title>\n    <updated>2026-03-16T07:42:38Z</updated>\n    <link href='https://arxiv.org/abs/2603.14939v1' rel='alternate' type='text/html'/>\n    <link href='https://arxiv.org/pdf/2603.14939v1' rel='related' title='pdf' type='application/pdf'/>\n    <summary>We investigate whether the first discovered fluorine-rich CEMP-no star, CS 29498$-$043, can be explained by a very metal-poor rotating massive star. We consider single rotating stellar models of 20 $M_{\\odot}$ at a metallicity of $Z = 10^{-5}$, exploring initial rotation rates from $\\upsilon_{\\rm ini}/\\upsilon_{\\rm crit} = 0$ to $0.7$ in increments of $0.1$ ($0&lt;\\upsilon_{\\rm ini}&lt;644$ km s$^{-1}$). Rotational mixing enhances the production of light elements in the H--He layers, including fluorine. The ejected material can be nitrogen-rich without being fluorine-rich, whereas fluorine-rich ejecta are always predicted to be nitrogen-rich. The model providing the best fit to the abundances of CS 29498$-$043 is the $\\upsilon_{\\rm ini}/\\upsilon_{\\rm crit} = 0.6$ model ($\\upsilon_{\\rm ini} = 547$ km s$^{-1}$), which reproduces C, N, O, Na, Mg, and Al within the observational uncertainties. However, the predicted [F/Fe] $=2.8$ exceeds the observed value of [F/Fe] $=2.0 \\pm 0.4$. By simultaneously varying the $^{15}$N($α,γ$)$^{19}$F and $^{19}$F($α,p$)$^{22}$Ne reaction rates within their acceptable ranges, the [F/Fe] ratio in the $\\upsilon_{\\rm ini}/\\upsilon_{\\rm crit} = 0.6$ model can be reduced to 2.2, providing a plausible solution to the abundance pattern of CS 29498$-$043. Our results support the hypothesis that fluorine-rich CEMP-no stars may originate from material enriched by a single, metal-poor, rotating massive star. A potential observational test of this scenario may be to check whether the nitrogen and fluorine abundances observed at the surface of CEMP-no stars are correlated.</summary>\n    <category scheme='http://arxiv.org/schemas/atom' term='astro-ph.SR'/>\n    <category scheme='http://arxiv.org/schemas/atom' term='astro-ph.GA'/>\n    <published>2026-03-16T07:42:38Z</published>\n    <arxiv:comment>Accepted in EPJA. Special issue titled \"About Stars and Nuclei: Honoring the Legacy of Roberto Gallino\"</arxiv:comment>\n    <arxiv:primary_category term='astro-ph.SR'/>\n    <author>\n      <name>Arthur Choplin</name>\n    </author>\n    <author>\n      <name>Georges Meynet</name>\n    </author>\n  </entry>"
}