Element synthesis calculations for stellar explosions: robust uncertainties, sensitivities, and radioactive ion beam measurements

Classical novae and type I X-ray bursts: Challenges for the 21st century

“…Hydrodynamic tests using current uncertainties for these rates (and others mentioned above, such as 23 Mg(p, γ)) are encouraged. Finally, we note that rates of the 14 O(α, p) and 15 O(a, γ) reactions have no significant impact on nova nucleosynthesis in standard models 28,169,191,192 . Some nova models that explore quite extreme, rare scenarios (low accretion rates 142 or accretion of extremely metal-poor material 141 ) have been published in recent years.…”

“…Other important reaction-rates identified in the post-processing studies of Iliadis et al 28 include 22 Ne(p, γ) 23 Na, 26 Mg(p, γ) 27 Al, 29 Si(p, γ) 30 P, 33 Cl(p, γ) 34 Ar, 34 S(p, γ) 35 Cl, 34 Cl(p, γ) 35 Ar, 37 Ar(p, γ) 38 K, and 38 K(p, γ) 39 Ca; other rates affecting the production of radioisotopes, as identified by Smith et al 169 and Hix et al 168 include 16 O(p, γ) 17 F, 20 Ne(p, γ) 21 Na, and 25 Mg(p, γ) 26 Al. Hydrodynamic tests using current uncertainties for these rates (and others mentioned above, such as 23 Mg(p, γ)) are encouraged.…”

“…19 Ne and 18 F(p, α) 15 O Using a 1-D hydrodynamic model, Coc et al 166 found that the calculated 18 F abundance varied by a factor of ≈ 300 when comparing results using their low and high 18 F+p rates (at 0.2 GK, the ratio of the high to low rate was about one and two orders of magnitude for the (p, γ) and (p, α) rates, respectively). When individually varied by the adopted uncertainties (a maximum of a factor of 15 and a factor of 30 for the (p, γ) and (p, α) rates, respectively, over T peak = 0.1 − 0.4 GK) in the postprocessing studies of Iliadis et al 28 , the final calculated abundances of 16 O, 17 O and post-processing study conducted with a Monte Carlo approach to rate variations, the 18 F(p, α) reaction is given in a prioritized list of reactions that affect the production of the radioisotope 18 F 168,169 . Using a multi-zone post-processing approach 160 , Bardayan et al 174 and Kozub et al 175 reported that roughly twice as much 18 F was produced when using a (p, α) rate ≈ 1.5 − 2 times lower and ≈ 5 times lower, respectively, than that of Coc et al 166 at nova temperatures.…”

“…When individually varied by the adopted uncertainty (a factor of 100) in the postprocessing studies of Iliadis et al 28 , the final calculated abundances of 21 Ne, 22 Na and 22 Ne varied by at least a factor of two. In a one-zone post-processing study conducted with a Monte Carlo approach to rate variations, the 21 Na(p, γ) reaction is given in a prioritized list of reactions that affect the production of 22 Na 168,169 . Using a 1-D hydrodynamic model, Bishop et al 179 and Davids et al 180 found that 22 Na production decreased by about 20% when results using two rates differing by a factor of ≈ 5 (at 0.2 GK) were compared.…”

“…Al (Coc et al165 , using a semi-analytical treatment; Coc et al166 , José et al167 , using a 1-D hydrodynamical model) and the production of certain elemental abundances that may help to assess the peak temperature or degree of mixing in a nova (Downen et al134 and Kelly et al135 , using post-processing of multiple zones from 1-D hydrodynamic models).Partial results from comprehensive one-zone Monte Carlo sensitivity studies have also been reported168,169 , where uncertainties were assumed as ≈50% for rates whose measurement would require radioactive beams, a factor of two for rates calculated through statistical models, and ≈20% for all other non-weak interaction rates.…”