Nuclear composition and heating in accreting neutron - star crusts

Nuclear reactions in accreting neutron-star crusts and the heat release accompanying them are studied, under different assumptions concerning the composition of the outermost layer formed of the ashes of X-ray bursts. Particular examples of ashes containing nuclides with A ~ 90-110 are considered and compared with a standard A=56 case. In all cases, evolution of a crust shell is followed from 10^8 g/cm^3 to a few times 10^{13} g/cm^3. The total crustal heating produced in the non-equilibrium processes in the accreting crust is 1.1-1.5 MeV per one accreted nucleon. The composition of the accreted crust at densities exceeding the threshold for the pycnonuclear fusion is essentially independent of the assumed initial composition of the X-ray burst ashes.

Note:

5 pages, 2 figures, accepted for publication in A&A Letters

References(5)

Figures(0)

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•
e-Print:
- astro-ph/0010572
•
DOI:
- 10.1086/319107

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The Endpoint of the rp process on accreting neutron stars

Hendrik Schatz
(
- Michigan State U. and
- Michigan State U., NSCL
)
,
A. Aprahamian
(
- Notre Dame U.
)
,
V. Barnard
(
- Notre Dame U.
)
,
L. Bildsten
(
- Santa Barbara, KITP
)
,
A. Cumming
(
- Santa Barbara, KITP
)

et al.

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- Phys.Rev.Lett. 86 (2001) 16, 3471-3474
•
e-Print:
- astro-ph/0102418
•
DOI:
- 10.1103/PhysRevLett.86.3471