| 摘 要： | We investigate the relationship between the rise width and the full width of gamma-ray burst pulses.Theoretical analysis shows that either width is proportional to Γ~(-2)Δ_(Тθ),FWHM(RRc)/c(Γ the Lorentz factor of the bulk motion,Δ_(Тθ),FWHM a local pulse's width,R_c the radius of fireballs and c the velocity of light).We study the relationship for four samples of observed pulses.We find:(1)merely the curvature effect could reproduce the relationship between the rise and full widths with the same slope as derived from the model of Qin et al.;(2)gamma-ray burst pulses,selected from both the short and long GRBs,follow the same sequence in the rise width vs. full width diagram,with the shorter pulses at one end;(3)all GRBs may intrinsically result from local Gaussian pulses.These features place constraints on the physical mechanism(s)for producing long and short GRBs.
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