The dependence of spectral lag on pulse properties

Author: Pavel Minaev

Abstract: The dependence of a spectral lag against energy band of INTEGRAL bursts was investigated. It was found that for single pulse bursts or well separated pulses of multi-pulsed bursts the spectral lag - energy band relation can be approximated by the logarithmic law τ ∼ Alog(E), where E is energy band. It is interesting that parameter A correlates with pulse duration. The correlation is presumably the same for long and for short bursts. Negative lag in single pulse bursts or in well separated pulses was not found. Negative lag can appear while investigating the whole profile of multi-pulsed burst and may be resulted from differences in spectral parameters of pulses (e.g. spectral hardness). The pulse and interpulse durations were also investigated.