## Neutron reactions in accreting neutron stars: a new pathway to efficient crust heating

##### Authors
Gupta, Sanjib S.
Kawano, Toshihiko
Möller, Peter
##### Description
In our calculation of neutron star crust heating we include several key new model features. In earlier work electron capture (EC) only allowed neutron emission from the daughter ground-state; here we calculate, in a deformed QRPA model, EC decay rates to all states in the daughter that are allowed by Gamow-Teller selection rules and energetics. The subsequent branching ratios between the 1n,...,xn channels and the competing $\gamma$-decay are calculated in a Hauser-Feshbach model. Since EC accesses excited states, many more neutrons are emitted in our calculation than in previous work, leading to accelerated reaction flows. In our multi-component plasma model a single (EC,xn) reaction step can produce several neutron-deficient nuclei, each of which can further decay by (EC,xn). Hence, the neutron emission occurs more continuously with increasing depth as compared to that in a one-component plasma model.
Comment: Two color figures, accepted for publication by Physical Review Letters
Astrophysics