Speaker
Mrs
Roberta Del Vecchio
(Astronomical Observatory of the Jagiellonian University)
Description
In this work we study the distribution of temporal power-law decay indices, $\alpha$, in the Gamma Ray Burst (GRB) afterglow
phase,
fitted for a sample of $164$ long GRBs with known redshifts using a power-law form. These indices are compared to the values of characteristic afterglow
luminosity,
$L_a$, the time, $T_a^*$, and the analogous decay index, $\alpha_W$, derived with global light curve fitting using the Willingale et al. (2007) model.
This model fitting yields similar distributions of $\alpha_W$ to the fitted $\alpha$, but for several bursts difference between
these indices
can be significant. Analysis of the ($\alpha$, $L_a$) distribution reveals a weak correlation of these quantities. However, we
discovered
a significant regular trend when studying distribution of GRB $\alpha$ values at the $L_a$, vs. $T_a^*$ (LT) plane,
with a differences of the $\alpha$ parameters below and above the fitted LT correlation line (Dainotti et al. 2008).
Study of the presented systematic trend may allow one for constraining the physical models for GRBs. A proposed toy model accounting
for this systematics applied to the analyzed GRB distribution results in increasing the LT correlation coefficient.
Collaboration | Del Vecchio Roberta, Dainotti Maria Giovanna, Ostrowski Michał |
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Primary author
Mrs
Roberta Del Vecchio
(Astronomical Observatory of the Jagiellonian University)
Co-authors
Dr
Maria Giovanna Dainotti
(Stanford University)
Prof.
Michał Ostrowski
(Astronomical Observatory Jagiellonian University)