We demonstrate that gamma-ray burst afterglow spectra and light curves can be calculated for arbitrary explosion and radiation parameters by scaling the peak flux and the critical frequencies connecting different spectral regimes. Only one baseline c
alculation needs to be done for each jet opening angle and observer angle. These calculations are done numerically using high-resolution relativistic hydrodynamical afterglow blast wave simulations which include the two-dimensional dynamical features of expanding and decelerating afterglow blast waves. Any light curve can then be generated by applying scaling relations to the baseline calculations. As a result, it is now possible to fully fit for the shape of the jet break, e.g. at early time X-ray and optical frequencies. In addition, late-time radio calorimetry can be improved since the general shape of the transition into the Sedov-Taylor regime is now known for arbitrary explosion parameters so the exact moment when the Sedov-Taylor asymptote is reached in the light curve is no longer relevant. When calculating the baselines, we find that the synchrotron critical frequency and the cooling break frequency are strongly affected by the jet break. The synchrotron break temporal slope quickly drops to the steep late time Sedov-Taylor slope, while the cooling break first steepens then rises to meet the level of its shallow late time asymptote.
We present results for a large number of gamma-ray burst (GRB) afterglow light curve calculations, done by combining high resolution two-dimensional relativistic hydrodynamics simulations using RAM with a synchrotron radiation code. Results were obta
ined for jet energies, circumburst medium densities and jet angles typical for short and underluminous GRBs, different observer angles and observer frequencies from low radio (75 MHz) to X-ray (1.5 keV). We summarize the light curves through smooth power law fits with up to three breaks, covering jet breaks for small observer angles, the rising phase for large observer angles and the rise and decay of the counterjet. All light curve data are publicly available via http://cosmo.nyu.edu/afterglowlibrary . The data can be used for model fits to observational data and as an aid for predicting observations by future telescopes such as LOFAR or SKA and will benefit the study of neutron star mergers using different channels, such as gravitational wave observations with LIGO or Virgo. For small observer angles, we find jet break times that vary significantly between frequencies, with the break time in the radio substantially postponed. Increasing the observer angle also postpones the measured jet break time. The rising phase of the light curve for large observer angle has a complex shape that can not always be summarized by a simple power law. Except for very large observer angles, the counter jet is a distinct feature in the light curve, although in practice the signal will be exceedingly difficult to observe by then.
