Speaker
Description
Classical novae are stellar thermonuclear explosions that occur when a white dwarf accretes material from a companion star. In the early Galactic history, and still today in metal-poor environments, these explosions likely proceeded differently due to the accretion of sub-solar metallicity material. It has been suggested that such low-metallicity novae produced distinct abundance patterns compared to their more recent counterparts [1]. In particular, nuclear processes in low-metallicity novae extend up to the Cu-Zn region, resembling a weak rp-process, whereas classical novae typically terminate around Ca. In this talk, we investigate nucleosynthesis in this scenario and assess the impact of nuclear physics uncertainties on the final abundance pattern. Using a Monte Carlo approach [2,3], we varied all relevant reaction rates within their uncertainties to identify key nuclear processes influencing the production of intermediate-mass nuclei [4]. Our results highlight specific reactions whose uncertainties significantly affect nucleosynthesis under low-metallicity-nova conditions [5]. These reactions require experimental measurements at both stable and radioactive beam facilities to improve their rate precision. To begin addressing these uncertainties, we discuss recent indirect (³He,d) transfer measurements conducted at the Triangle Universities Nuclear Laboratory (TUNL) using the Enge split-pole spectrograph. These measurements provide crucial constraints on (p,γ) reaction rates, improving our understanding of nucleosynthesis in low-metallicity novae.
- This work is supported by U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Award Number DE-SC0017799 and Contract Nos. DE-FG02-97ER41033 and DE-FG02-97ER41042.
References
[1] J. José et al., Astrophys. J 622, L103 (2007).
[2] A.L. Sallaska et al., Astrophys. J Suppl. Ser. 207, 18 (2013).
[3] R. Longland et al., Nucl. Phys. A 841, 1 (2010).
[4] C. Iliadis and A. Coc, Astrophys. J 901, 127 (2020).
[5] A. Psaltis et al. (in preparation).
