Spectroscopic Modeling of Luminous Transients Powered by H-Rich and He-Rich Circumstellar Interaction

TL;DR

This paper uses advanced spectroscopic modeling to study how circumstellar material influences the spectral features and evolution of hydrogen-rich and hydrogen-poor superluminous supernovae, revealing key indicators of progenitor mass-loss history.

Contribution

It introduces a comprehensive radiative transfer simulation framework with the SuperLite code to systematically analyze CSM effects on supernova spectra, highlighting new spectroscopic diagnostics.

Findings

Hydrogen lines correlate with dense, extended CSM in SLSN-II.

Early spectra of hydrogen-poor SLSNe are mostly featureless, with weak hydrogen lines.

Spectroscopic evolution reveals progenitor and CSM properties.

Abstract

In this study, we perform detailed spectroscopic modeling to analyze the interaction of circumstellar material (CSM) with ejecta in both hydrogen-rich and hydrogen-poor superluminous supernovae (SLSNe), systematically varying properties such as CSM density, composition, and geometry to explore their effects on spectral lines and light curve evolution. Using advanced radiative transfer simulations with the new, open-source SuperLite code to generate synthetic spectra, we identify key spectroscopic indicators of CSM characteristics. Our findings demonstrate that spectral lines of hydrogen and helium exhibit significant variations due to differences in CSM mass and composition. In hydrogen-rich SLSN- II, we observe pronounced hydrogen emission lines that correlate strongly with dense, extended CSM, suggesting massive, eruptive mass-loss histories. Conversely, in hydrogen-poor SLSNe, we recover mostly featureless spectra at early times, with weak hydrogen lines appearing only in the very early phases of the explosion, highlighting the quick ionization of traces of hydrogen present in the CSM. We analyze the properties of the resulting emission lines, particularly $\rm H_{\alpha}$ and $\rm H_{\beta}$, for our models using sophisticated statistical methods. This analysis reveals how variations in the supernova progenitor and CSM properties can lead to distinct spectroscopic evolutions over time. These temporal changes provide crucial insights into the underlying physics driving the explosion and the subsequent interaction with the CSM. By linking these spectroscopic observations to the initial properties of the progenitor and its surrounding ma