Poonam Chandra, Dale A. Frail
We present a catalog of radio afterglow observations of gamma-ray bursts
(GRBs) over a 14 year period from 1997 to 2011. Our sample of 304 afterglows
consists of 2995 flux density measurements (including upper limits) at
frequencies between 0.6 GHz and 660 GHz, with the majority of data taken at 8.5
GHz frequency band (1539 measurements). We use this dataset to carry out a
statistical analysis of the radio-selected sample. The detection rate of radio
afterglows has stayed unchanged almost at 31% before and after the launch of
the {\em Swift} satellite. The canonical long-duration GRB radio light curve at
8.5 GHz peaks at 3-6 days in the source rest frame, with a median peak
luminosity of $10^{31}$ erg s$^{-1}$ Hz$^{-1}$. The peak radio luminosities for
short-hard bursts, X-ray flashes and the supernova-GRB classes are an order of
magnitude or more fainter than this value. There are clear relationships
between the detectability of a radio afterglow and the fluence or energy of a
GRB, and the X-ray or optical brightness of the afterglow. However, we find few
significant correlations between these same GRB and afterglow properties and
the peak radio flux density. We also produce synthetic light curves at
centimeter and millimeter bands using a range of blastwave and microphysics
parameters derived from multiwavelength afterglow modeling, and we use them to
compare to the radio sample. Finding agreement, we extrapolate this behavior to
predict the centimeter and millimeter behavior of GRBs observed by the Expanded
Very Large Array (EVLA) and the Atacama Large Millimeter Array (ALMA).
View original:
http://arxiv.org/abs/1110.4124
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