The Observer’s Guide to the Gamma-Ray Burst Supernova Connection

Figure 4

An example decomposition of the optical (-band) light curve of GRB 090618 [10]. (a) For a given GRB-SN event, the single-filter monochromatic flux is attributed as arising from three sources: the AG, the SN, and a constant source of flux from the host galaxy. (b) Once the observations have been dereddened, the host flux is removed, either via the image-subtraction technique or by being mathematically subtracted away. At this point a mathematical model composed of one or more power laws punctuated by break-times is fit to the early light curve to determine the temporal behaviour of the AG. (c) Once the AG model has been determined, it is subtracted from the observations leaving just light from the SN.

(a)

(b)

(c)