The role of radioactive nickel in shaping the plateau phase of Type II supernovae

Understand

In the present study, we systematically explore the effect of the radioactive 56Ni and its mixing properties in the ejecta on the plateau of Type IIP supernovae (SNe).

• We evaluate the importance of 56Ni in shaping light curves of SNe IIP by simulating light curves for two red supergiant models using different amounts of 56Ni and with different types of mixing: uniform distribution of 56Ni out to different fractions of the envelope and "boxcar" distribution of 56Ni.
• We find, similarly to previous studies, that 56Ni extends duration of the plateau.
• We find a formula to estimate the extension based on the observed bolometric light curves and show that for most SNe IIP 56Ni extends the plateau by about 20%.