Radiation Hydrodynamical Models for Type I Superluminous Supernovae

Abstract

The physical origin of Type I superluminous supernovae (SLSNe-I), whose luminosities are 10 to 100 times brighter than normal core-collapse supernovae, remains still unknown. Radioactive-decays, magnetars, and circumstellar interactions have been proposed for the power source the light curves, although no definitive conclusions have been reached yet. Since most of light curve studies have been based on simplified semi-analytic models, we have constructed detailed light curve models for various mass of stars including very massive ones and large amount of mass loss with radiation hydrodynamical calculations. Here we focus on the magnetar and circumstellar interaction models and compare their rising time, peak luminosity, width, decline rate of the light curves with observations which show quite a large diversities. We then discuss how to discriminate these models, relevant models parameters, their evolutionary origins, possible roles of chemical enrichment of the early universe, and implications for the identifications of first stars.KEYWORDS: magnetar, stellar mass loss, supernovae, superluminous supernovae Superluminous SupernovaeSuperluminous supernovae (SLSNe) are brighter than −21 magnitude in any optical band at the maximum brightness, which is ≈ 30 times brighter than the average of normal supernovae [8,15]. They are divided into Type I (SLSN-I) and Type II (SLSN-II) according to the absence and presence of hydrogen feature in the spectra. It is evident that there is significant dispersion in both rise and decay time scales. These differences could indicate some diversity in the progenitors of SLSNe.SLSNe-II, like SN 2006gy, may be powered by interactions of the SN ejecta with CSM in the form of steady wind or a shell [12]. The origin of SLSNe-I is still a matter of debate [8]. Currently three possibilities are under consideration (a) pair instability supernovae, (b) supernovae powered by ejecta/wind interaction, and (c) supernovae powered by a spin down of a rapidly rotating young magnetar. In the present paper, we focus on the magnetar and circumstellar interaction models for SLSNe-I and discuss possible engines powering the observed super-luminosities.The existence of SLSNe opens the possibility of studying extremely luminous supernovae in the very early Universe. Understanding their nature will open new paths to better comprehend the origin and evolution of stars in the Universe.