University of Minnesota
School of Physics & Astronomy

Nuclear Physics Seminar

Wednesday, May 5th 2010
1:25 pm:
Nuclear Physics Seminar in 435 Physics
Speaker: Laurens Keek, University of Minnesota
Subject: Detailed models of superbursts from accreting neutron stars

Superbursts are the most energetic thermonuclear bursts observed from accreting neutron stars. Deep inside the envelope, close to the crust, a thick carbon-rich layer flashes. Afterwards it takes over a day for the neutron star surface to cool down. Because ignition takes place close to the crust, superbursts are sensitive to crustal heating. The amount of crustal heating depends on the nuclear physics in the crust and core, and is not well understood. Superbursts provide an observational measure to probe this. We present the first multi-zone models of series of recurring superbursts created with a hydrodynamic stellar evolution code that includes a large network of nuclear reactions. We obtain constraints for crustal heating by comparing our models to the scarce observational data. Furthermore, we discuss how our model reproduces characteristics of the observed light curve, such as details of the precursor burst that is seen just prior to the superburst.

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