Impact of the New 65As(p, γ)66Se Reaction Rate on the Two-proton Sequential Capture of 64Ge, Weak GeAs Cycles, and Type I X-Ray Bursts Such as the Clocked Burster GS 1826-24

Yi Hua Lam; Zi Xin Liu; Alexander Heger; Ning Lu; Adam Michael Jacobs; Zac Johnston

doi:10.3847/1538-4357/ac4d8b

Impact of the New ⁶⁵As(p, γ)⁶⁶Se Reaction Rate on the Two-proton Sequential Capture of ⁶⁴Ge, Weak GeAs Cycles, and Type I X-Ray Bursts Such as the Clocked Burster GS 1826-24

Yi Hua Lam
, Zi Xin Liu
, Alexander Heger
, Ning Lu
, Adam Michael Jacobs
, Zac Johnston

School of Physics and Astronomy

Research output: Contribution to journal › Article › Research › peer-review

15 Citations (Scopus)

Abstract

We reassess the 65As(p,γ)66Se reaction rates based on a set of proton thresholds of 66Se, S p(66Se), estimated from the experimental mirror nuclear masses, theoretical mirror displacement energies, and full p f-model space shell-model calculation. The self-consistent relativistic Hartree-Bogoliubov theory is employed to obtain the mirror displacement energies with much reduced uncertainty, and thus reducing the proton-threshold uncertainty up to 161 keV compared to the AME2020 evaluation. Using the simulation instantiated by the one-dimensional multi-zone hydrodynamic code, Kepler, which closely reproduces the observed GS 1826-24 clocked bursts, the present forward and reverse 65As(p,γ)66Se reaction rates based on a selected S p(66Se) = 2.469 ± 0.054 MeV, and the latest 22Mg(α,p)25Al, 56Ni(p,γ)57Cu, 57Cu(p,γ)58Zn, 55Ni(p,γ)56Cu, and 64Ge(p,γ)65As reaction rates, we find that though the GeAs cycles are weakly established in the rapid-proton capture process path, the 65As(p,γ)66Se reaction still strongly characterizes the burst tail end due to the two-proton sequential capture on 64Ge, not found by the Cyburt et al. sensitivity study. The 65As(p,γ)66Se reaction influences the abundances of nuclei A = 64, 68, 72, 76, and 80 up to a factor of 1.4. The new S p(66Se) and the inclusion of the updated 22Mg(α,p)25Al reaction rate increases the production of 12C up to a factor of 4.5, which is not observable and could be the main fuel for a superburst. The enhancement of the 12C mass fraction alleviates the discrepancy in explaining the origin of the superburst. The waiting point status of and two-proton sequential capture on 64Ge, the weak-cycle feature of GeAs at a region heavier than 64Ge, and the impact of other possible S p(66Se) are also discussed.

Original language	English
Article number	72
Number of pages	14
Journal	The Astrophysical Journal
Volume	929
Issue number	1
DOIs	https://doi.org/10.3847/1538-4357/ac4d8b
Publication status	Published - 1 Apr 2022

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10.3847/1538-4357/ac4d8bLicence: CC BY

Cite this

@article{caaa69ae52f4474ab642fd0cca0b7b01,

title = "Impact of the New 65As(p, γ)66Se Reaction Rate on the Two-proton Sequential Capture of 64Ge, Weak GeAs Cycles, and Type I X-Ray Bursts Such as the Clocked Burster GS 1826-24",

abstract = "We reassess the 65As(p,γ)66Se reaction rates based on a set of proton thresholds of 66Se, S p(66Se), estimated from the experimental mirror nuclear masses, theoretical mirror displacement energies, and full p f-model space shell-model calculation. The self-consistent relativistic Hartree-Bogoliubov theory is employed to obtain the mirror displacement energies with much reduced uncertainty, and thus reducing the proton-threshold uncertainty up to 161 keV compared to the AME2020 evaluation. Using the simulation instantiated by the one-dimensional multi-zone hydrodynamic code, Kepler, which closely reproduces the observed GS 1826-24 clocked bursts, the present forward and reverse 65As(p,γ)66Se reaction rates based on a selected S p(66Se) = 2.469 ± 0.054 MeV, and the latest 22Mg(α,p)25Al, 56Ni(p,γ)57Cu, 57Cu(p,γ)58Zn, 55Ni(p,γ)56Cu, and 64Ge(p,γ)65As reaction rates, we find that though the GeAs cycles are weakly established in the rapid-proton capture process path, the 65As(p,γ)66Se reaction still strongly characterizes the burst tail end due to the two-proton sequential capture on 64Ge, not found by the Cyburt et al. sensitivity study. The 65As(p,γ)66Se reaction influences the abundances of nuclei A = 64, 68, 72, 76, and 80 up to a factor of 1.4. The new S p(66Se) and the inclusion of the updated 22Mg(α,p)25Al reaction rate increases the production of 12C up to a factor of 4.5, which is not observable and could be the main fuel for a superburst. The enhancement of the 12C mass fraction alleviates the discrepancy in explaining the origin of the superburst. The waiting point status of and two-proton sequential capture on 64Ge, the weak-cycle feature of GeAs at a region heavier than 64Ge, and the impact of other possible S p(66Se) are also discussed. ",

author = "Lam, \{Yi Hua\} and Liu, \{Zi Xin\} and Alexander Heger and Ning Lu and Jacobs, \{Adam Michael\} and Zac Johnston",

note = "Funding Information: We are deeply grateful to H. Schatz for reading our manuscript and for providing thoughtful and constructive suggestions to improve the manuscript, and to B. A. Brown for providing the previous and updated S ( Se) and for reading and suggesting constructive thoughts to the part related to the S ( Se). We thank W. J. Huang for providing the information of AME. We also thank the anonymous referee for the helpful comments and remarks on this manuscript. We are very thankful to N. Shimizu for suggestions in tuning the KS hell code at the PHYS\_T3 (Institute of Physics) and QDR4 clusters (Academia Sinica Grid-computing Centre) of Academia Sinica, Taiwan, to D. Kahl for checking and implementing the newly updated Ni(p, γ) Cu reaction rate, to M. Smith for using the Computational Infrastructure for Nuclear Astrophysics, and to J. J. He for fruitful discussion. This work was financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (CAS, Grant Nos. XDB34000000 and XDB34020204) and the National Natural Science Foundation of China (No. 11775277). We are appreciative of the computing resource provided by the Institute of Physics (PHYS\_T3 cluster) and the Academia Sinica Grid-computing Center (ASGC) Distributed Cloud resources (QDR4 cluster) of Academia Sinica, Taiwan. Part of the numerical calculations was performed at the Gansu Advanced Computing Center. Y.H.L. gratefully acknowledges the financial support from the Chinese Academy of Sciences President{\textquoteright}s International Fellowship Initiative (No. 2019FYM0002) and appreciates the laptop (Dell M4800) partially sponsored by Pin-Kok Lam and Fong-Har Tang during the COVID-19 pandemic. A.H. is supported by the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav, No. CE170100004) and for All Sky Astrophysics in 3 Dimensions (ASTRO 3D, No. CE170100013). A.H., A.M.J., and Z.J. were supported, in part, by the US National Science Foundation under Grant No. PHY-1430152 (JINA Center for the Evolution of the Elements, JINA-CEE). p 66 p 66 56 57 Publisher Copyright: {\textcopyright} 2022. The Author(s). Published by the American Astronomical Society.",

year = "2022",

month = apr,

day = "1",

doi = "10.3847/1538-4357/ac4d8b",

language = "English",

volume = "929",

journal = "The Astrophysical Journal",

issn = "1538-4357",

publisher = "IOP Publishing",

number = "1",

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Impact of the New ⁶⁵As(p, γ)⁶⁶Se Reaction Rate on the Two-proton Sequential Capture of ⁶⁴Ge, Weak GeAs Cycles, and Type I X-Ray Bursts Such as the Clocked Burster GS 1826-24. / Lam, Yi Hua; Liu, Zi Xin; Heger, Alexander et al.
In: The Astrophysical Journal, Vol. 929, No. 1, 72, 01.04.2022.

Research output: Contribution to journal › Article › Research › peer-review

TY - JOUR

T1 - Impact of the New 65As(p, γ)66Se Reaction Rate on the Two-proton Sequential Capture of 64Ge, Weak GeAs Cycles, and Type I X-Ray Bursts Such as the Clocked Burster GS 1826-24

AU - Lam, Yi Hua

AU - Liu, Zi Xin

AU - Heger, Alexander

AU - Lu, Ning

AU - Jacobs, Adam Michael

AU - Johnston, Zac

N1 - Funding Information: We are deeply grateful to H. Schatz for reading our manuscript and for providing thoughtful and constructive suggestions to improve the manuscript, and to B. A. Brown for providing the previous and updated S ( Se) and for reading and suggesting constructive thoughts to the part related to the S ( Se). We thank W. J. Huang for providing the information of AME. We also thank the anonymous referee for the helpful comments and remarks on this manuscript. We are very thankful to N. Shimizu for suggestions in tuning the KS hell code at the PHYS_T3 (Institute of Physics) and QDR4 clusters (Academia Sinica Grid-computing Centre) of Academia Sinica, Taiwan, to D. Kahl for checking and implementing the newly updated Ni(p, γ) Cu reaction rate, to M. Smith for using the Computational Infrastructure for Nuclear Astrophysics, and to J. J. He for fruitful discussion. This work was financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (CAS, Grant Nos. XDB34000000 and XDB34020204) and the National Natural Science Foundation of China (No. 11775277). We are appreciative of the computing resource provided by the Institute of Physics (PHYS_T3 cluster) and the Academia Sinica Grid-computing Center (ASGC) Distributed Cloud resources (QDR4 cluster) of Academia Sinica, Taiwan. Part of the numerical calculations was performed at the Gansu Advanced Computing Center. Y.H.L. gratefully acknowledges the financial support from the Chinese Academy of Sciences President’s International Fellowship Initiative (No. 2019FYM0002) and appreciates the laptop (Dell M4800) partially sponsored by Pin-Kok Lam and Fong-Har Tang during the COVID-19 pandemic. A.H. is supported by the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav, No. CE170100004) and for All Sky Astrophysics in 3 Dimensions (ASTRO 3D, No. CE170100013). A.H., A.M.J., and Z.J. were supported, in part, by the US National Science Foundation under Grant No. PHY-1430152 (JINA Center for the Evolution of the Elements, JINA-CEE). p 66 p 66 56 57 Publisher Copyright: © 2022. The Author(s). Published by the American Astronomical Society.

PY - 2022/4/1

Y1 - 2022/4/1

N2 - We reassess the 65As(p,γ)66Se reaction rates based on a set of proton thresholds of 66Se, S p(66Se), estimated from the experimental mirror nuclear masses, theoretical mirror displacement energies, and full p f-model space shell-model calculation. The self-consistent relativistic Hartree-Bogoliubov theory is employed to obtain the mirror displacement energies with much reduced uncertainty, and thus reducing the proton-threshold uncertainty up to 161 keV compared to the AME2020 evaluation. Using the simulation instantiated by the one-dimensional multi-zone hydrodynamic code, Kepler, which closely reproduces the observed GS 1826-24 clocked bursts, the present forward and reverse 65As(p,γ)66Se reaction rates based on a selected S p(66Se) = 2.469 ± 0.054 MeV, and the latest 22Mg(α,p)25Al, 56Ni(p,γ)57Cu, 57Cu(p,γ)58Zn, 55Ni(p,γ)56Cu, and 64Ge(p,γ)65As reaction rates, we find that though the GeAs cycles are weakly established in the rapid-proton capture process path, the 65As(p,γ)66Se reaction still strongly characterizes the burst tail end due to the two-proton sequential capture on 64Ge, not found by the Cyburt et al. sensitivity study. The 65As(p,γ)66Se reaction influences the abundances of nuclei A = 64, 68, 72, 76, and 80 up to a factor of 1.4. The new S p(66Se) and the inclusion of the updated 22Mg(α,p)25Al reaction rate increases the production of 12C up to a factor of 4.5, which is not observable and could be the main fuel for a superburst. The enhancement of the 12C mass fraction alleviates the discrepancy in explaining the origin of the superburst. The waiting point status of and two-proton sequential capture on 64Ge, the weak-cycle feature of GeAs at a region heavier than 64Ge, and the impact of other possible S p(66Se) are also discussed.

AB - We reassess the 65As(p,γ)66Se reaction rates based on a set of proton thresholds of 66Se, S p(66Se), estimated from the experimental mirror nuclear masses, theoretical mirror displacement energies, and full p f-model space shell-model calculation. The self-consistent relativistic Hartree-Bogoliubov theory is employed to obtain the mirror displacement energies with much reduced uncertainty, and thus reducing the proton-threshold uncertainty up to 161 keV compared to the AME2020 evaluation. Using the simulation instantiated by the one-dimensional multi-zone hydrodynamic code, Kepler, which closely reproduces the observed GS 1826-24 clocked bursts, the present forward and reverse 65As(p,γ)66Se reaction rates based on a selected S p(66Se) = 2.469 ± 0.054 MeV, and the latest 22Mg(α,p)25Al, 56Ni(p,γ)57Cu, 57Cu(p,γ)58Zn, 55Ni(p,γ)56Cu, and 64Ge(p,γ)65As reaction rates, we find that though the GeAs cycles are weakly established in the rapid-proton capture process path, the 65As(p,γ)66Se reaction still strongly characterizes the burst tail end due to the two-proton sequential capture on 64Ge, not found by the Cyburt et al. sensitivity study. The 65As(p,γ)66Se reaction influences the abundances of nuclei A = 64, 68, 72, 76, and 80 up to a factor of 1.4. The new S p(66Se) and the inclusion of the updated 22Mg(α,p)25Al reaction rate increases the production of 12C up to a factor of 4.5, which is not observable and could be the main fuel for a superburst. The enhancement of the 12C mass fraction alleviates the discrepancy in explaining the origin of the superburst. The waiting point status of and two-proton sequential capture on 64Ge, the weak-cycle feature of GeAs at a region heavier than 64Ge, and the impact of other possible S p(66Se) are also discussed.

UR - https://www.scopus.com/pages/publications/85129654702

U2 - 10.3847/1538-4357/ac4d8b

DO - 10.3847/1538-4357/ac4d8b

M3 - Article

AN - SCOPUS:85129654702

SN - 1538-4357

VL - 929

JO - The Astrophysical Journal

JF - The Astrophysical Journal

IS - 1

M1 - 72

ER -

Impact of the New ⁶⁵As(p, γ)⁶⁶Se Reaction Rate on the Two-proton Sequential Capture of ⁶⁴Ge, Weak GeAs Cycles, and Type I X-Ray Bursts Such as the Clocked Burster GS 1826-24

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Impact of the New 65As(p, γ)66Se Reaction Rate on the Two-proton Sequential Capture of 64Ge, Weak GeAs Cycles, and Type I X-Ray Bursts Such as the Clocked Burster GS 1826-24

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ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions

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Impact of the New ⁶⁵As(p, γ)⁶⁶Se Reaction Rate on the Two-proton Sequential Capture of ⁶⁴Ge, Weak GeAs Cycles, and Type I X-Ray Bursts Such as the Clocked Burster GS 1826-24