Comparison of burst properties between FRB 20190520B and FRB 20121102A

A comparative analysis of the individual bursts between FRB 20190520B and FRB 20121102A is presented by compiling a sample of bursts in multiple wavelengths. It is found that the peak frequency (nu(p)) distribution of the bursts of FRB 20190520B illustrates four discrete peaks in similar to 1-6 GHz and their spectral width distribution can be fitted with a lognormal function peaking at 0.35 GHz. The discrete nu(p) distribution and the narrow-banded spectral feature are analogous to FRB 20121102A. The burst duration of FRB 20190520B in the rest frame averages to 10.72 ms, longer than that of FRB 20121102A by a factor 3. The specific energy (E-mu c) at 1.25 GHz of FRB 20190520B observed with the Five-hundred-meter Aperture Spherical Radio Telescope narrowly ranges in [0.4, 1] x 10(38) erg, different from the bimodal E-mu c distribution of FRB 20121102A. Assuming a Gaussian spectral profile of the bursts, our Monte Carlo simulation analysis suggests that a power law (PL) or a cut-off power-law (CPL) energy function can comparably reproduce the E-mu c distribution of FRB 20190520B. The derived energy function index of the PL model is 4.46 +/- 0.17, much steeper than that of FRB 20121102A (1.82(-0.30)(+0.10)). For the CPL model, we obtain an index of 0.47 and a cut-off energy of 7.4 x 10(37) erg. Regarding the predicted nu(p) distribution in 1-2 GHz, the CPL model is more preferred than the PL model. These results indicate that FRB 20190520B and FRB 20121102A share similar spectral properties, but their energy functions are intrinsically different.