Advancement of Photospheric Radius Expansion and Clocked Type-I X-Ray Burst Models with the New <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Mg</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>22</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mi>α</mml:mi><mml:mo>,</mml:mo><mml:mi>p</mml:mi><mml:mo stretchy="false">)</mml:mo><mml:mmultiscripts><mml:mrow><mml:mi>Al</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>25</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math> Reaction Rate Determined at the Gamow Energy
Jun Hu, H. Yamaguchi, Y. H. Lam, Alexander Heger, D. Kahl, Adam Michael Jacobs, Zac Johnston, Shutao Xu, N. T. Zhang, S. B., L. H. Ru, Enqiang Liu, Tong Liu, S. Hayakawa, L. Yang, Hideki Shimizu, C. B. Hamill, A. St. J. Murphy, Jun Su, Xiao Fang, K. Y. Chae, M. S. Kwag, S. M. Cha, Nguyễn Ngọc Duy, Nguyen Kim Uyen, Dong H. Kim, R. G. Pizzone, M. La Cognata, S. Cherubini, S. Romano, А. Туміно, J. F. Liang, A. Psaltis, Michele Sferrazza, D. Kim, Yingying Li, S. Kubono
Abstract
We report the first (in)elastic scattering measurement of $^{25}\mathrm{Al}+p$ with the capability to select and measure in a broad energy range the proton resonances in $^{26}\mathrm{Si}$ contributing to the $^{22}\mathrm{Mg}(\ensuremath{\alpha},p)$ reaction at type I x-ray burst energies. We measured spin-parities of four resonances above the $\ensuremath{\alpha}$ threshold of $^{26}\mathrm{Si}$ that are found to strongly impact the $^{22}\mathrm{Mg}(\ensuremath{\alpha},p)$ rate. The new rate advances a state-of-the-art model to remarkably reproduce light curves of the GS $1826--24$ clocked burster with mean deviation $<9%$ and permits us to discover a strong correlation between the He abundance in the accreting envelope of the photospheric radius expansion burster and the dominance of $^{22}\mathrm{Mg}(\ensuremath{\alpha},p)$ branch.