STARLIB: A next-generation reaction-rate library for nuclear astrophysics

Abstract

STARLIB is a next-generation, all-purpose nuclear reaction-rate library. For the first time, this library provides the rate probability density at all temperature grid points for convenient implementation in models of stellar phenomena. The recommended rate and its associated uncertainties are also included. Currently, uncertainties are absent from all other rate libraries, and, although estimates have been attempted in previous evaluations and compilations, these are generally not based on rigorous statistical definitions. A common standard for deriving uncertainties is clearly warranted. STARLIB represents a first step in addressing this deficiency by providing a tabular, up-to-date database that supplies not only the rate and its uncertainty but also its distribution. Because a majority of rates are lognormally distributed, this allows the construction of rate probability densities from the columns of STARLIB. This structure is based on a recently suggested Monte Carlo method to calculate reaction rates, where uncertainties are rigorously defined. In STARLIB, experimental rates are supplemented with: (1) theoretical TALYS rates for reactions for which no experimental input is available, and (2) laboratory and theoretical weak rates. STARLIB includes all types of reactions of astrophysical interest to Z = 83, such as (p, γ ), (p, α), (α, n), and corresponding reverse rates. Strong rates account for thermal target excitations. Here, we summarize our Monte Carlo formalism, introduce the library, compare methods of correcting rates for stellar environments, and discuss how to implement our library in Monte Carlo nucleosynthesis studies. We also present a method for accessing STARLIB on the Internet and outline updated Monte Carlo-based rates.

Hydrodynamic simulations of classical novae outbursts and their evolution to supernova Ia explosions

“…They are NOVA (38; 39; 40, and references therein) and MESA (41; 42; 43; 44; 45, and references therein). NOVA is a one-dimensional (1-D), implicit, hydrodynamic, computer code which includes a nuclear reaction network that has been extended to 187 nuclei (up to 64 Ge and including the pep reaction), the OPAL opacities (46, and references therein), the Starlib nuclear reaction rates (47), the Timmes equations of state (48; 49), and the nuclear reaction network solver developed by (50). NOVA also includes the (51) algorithm for mixing-length convection and the Potekhin electron conduction opacities described in (52, and references therein).…”

Hydrodynamic Simulations of Classical Novae: Accretion onto CO White Dwarfs as SN Ia Progenitors

“…NOVA is a one-dimensional (1-D), implicit, hydrodynamic, computer code which has been well tested against a number of standard problems and weapon codes (45; 46). It includes a nuclear reaction network that has been extended to 187 nuclei (up to 64 Ge and including the pep reaction), the OPAL opacities (54, and references therein), the Starlib nuclear reaction rates (55), the Timmes equations of state (56; 57), and the nuclear reaction network solver developed by (58). NOVA also includes the (59) algorithm for mixing-length convection and the Potekhin electron conductivities described in (60, and references therein).…”

“…There are now a number of studies of grain formation in CN outbursts (78; 79; 80; 81; 82). In addition, we now use the STARLIB reaction rate library (55) which improves the rates for many of the light nuclear reactions. Temperature (K) Figure 4: The variation with time of the temperature in the deepest hydrogen-rich zone around the time when peak temperature occurs for the simulations with 25% core material and 75% accreted material.…”

Newly Discovered Low Energy Resonances In The 22Ne(p,γ)23Na At Luna

“…20 Ne(p,γ) 21 Figure 1: TNRR of the different reactions involved in the NeNa cycle. 22 Na(p, γ) 23 Mg reaction rate is from [4]. 22 Ne(p, γ) 23 Na reaction rate is from [5].…”

“…The reaction rate has been calculated in 1999 by the NACRE collaboration [25] from the resonance measurements [8,9] and the direct capture component [9]. Later on, a similar evaluation has been performed in 2001 [14], updated in 2010 [10,11] and again in 2013 [4] by the STARLIB group, completely disregarding the uncertain resonances. As a result, the NACRE and the STARLIB compilations differ up to a factor of 1000.…”