Burning in the Tail: Implications for a Burst Oscillation Model
Burning in the Tail: Implications for a Burst Oscillation Model
Chambers, F.; Watts, A.; Keek, L.; Cavecchi, Y.; Garcia Gonzalez, F.
Abstract
Accreting neutron stars (NSs) can exhibit high-frequency modulations, known as burst oscillations, in their light curves during thermonuclear X-ray bursts. Their frequencies can be offset from the spin frequency of the NS (known independently) by several Hz, and can drift by 1-3 Hz. One plausible explanation for this phenomenon is that a wave is present in the bursting ocean that decreases in frequency (in the rotating frame) as the burst cools. The strongest candidate is the buoyant r-mode; however, models for the burning ocean background used in previous studies over-predict frequency drifts by several Hz. Using new background models (which include shallow heating, and burning in the tail of the burst) the evolution of the buoyant r-mode is calculated. The resulting frequency drifts are smaller, in line with observations. This illustrates the importance of accounting for the detailed nuclear physics in these bursts.
-
Astrophysical Journal 871(2019)1, 61
DOI: 10.3847/1538-4357/aaf501
Cited 10 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-28775