J/ApJ/844/139 Atomic mass excesses (Schatz+, 2017)
Dependence of X-ray burst models on nuclear masses.
Schatz H., Ong W.-J.
<Astrophys. J., 844, 139 (2017)>
=2017ApJ...844..139S 2017ApJ...844..139S
ADC_Keywords: Atomic physics ; Models
Keywords: nuclear reactions, nucleosynthesis, abundances; X-rays: bursts
Abstract:
X-ray burst model predictions of light curves and the final
composition of the nuclear ashes are affected by uncertain nuclear
masses. However, not all of these masses are determined experimentally
with sufficient accuracy. Here we identify the remaining nuclear mass
uncertainties in X-ray burst models using a one-zone model that takes
into account the changes in temperature and density evolution caused
by changes in the nuclear physics. Two types of bursts are
investigated-a typical mixed H/He burst with a limited rapid proton
capture process (rp-process) and an extreme mixed H/He burst with an
extended rp-process. When allowing for a 3σ variation, only
three remaining nuclear mass uncertainties affect the light-curve
predictions of a typical H/He burst (27P, 61Ga, and 65As), and
only three additional masses affect the composition strongly (80Zr,
81Zr, and 82Nb). A larger number of mass uncertainties remain to
be addressed for the extreme H/He burst, with the most important being
58Zn, 61Ga, 62Ge, 65As, 66Se, 78Y, 79Y, 79Zr, 80Zr,
81Zr, 82Zr, 82Nb, 83Nb, 86Tc, 91Rh, 95Ag, 98Cd,
99In, 100In, and 101In. The smallest mass uncertainty that still
impacts composition significantly when varied by 3σ is 85Mo
with 16keV uncertainty. For one of the identified masses, 27P, we
use the isobaric mass multiplet equation to improve the mass
uncertainty, obtaining an atomic mass excess of -716(7)keV. The
results provide a roadmap for future experiments at advanced rare
isotope beam facilities, where all the identified nuclides are
expected to be within reach for precision mass measurements.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 25 3493 Atomic mass excesses used in this work
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ENum [1/118] Element number
5- 7 I3 --- MNum [2/295] Mass number
9- 15 F7.3 MeV Excess [-91.7/201.5] Atomic mass excess
17- 21 F5.3 MeV e_Excess [0/2.1] Uncertainty in Excess
23- 25 A3 --- r_Excess Source of Excess (1)
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Note (1): Source as follows:
Exp = Experimental value in Atomic Mass Evaluation AME2012
(Wang+ 2012ChPhC..36....3W 2012ChPhC..36....3W);
XTP = Extrapolation in AME2012;
CDE = Coulomb Displacement Energy calculation (Brown+ 2002PhRvC..65d5802B 2002PhRvC..65d5802B).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Mar-2018