Tomography analysis of the intermediate-luminosity Type Iax SN 2024pxl

Abstract

We present an abundance tomography analysis of SN 2024pxl, an intermediate-luminosity Type Iax supernova (M_ =-16.82 ± 0.19 mag), with the most-detailed follow-up in the Type Iax subclass to date. As one of the few intermediate-luminosity Type Iax objects, SN 2024pxl may link the two extremes of the peculiar thermonuclear supernova subclass. To test this hypothesis, we analyzed its spectral evolution through the first 100 days after the explosion and aim to probe the structure of its ejecta. We conducted an abundance--tomography analysis using synthetic spectra produced with the one-dimensional radiative-transfer code TARDIS. The fit of the spectral time series provides a radial scan of physical properties and probes the stratification of chemical elements throughout most of the supernova (SN) ejecta. The observed spectral evolution is well fit with the final model, in line with the general predictions of the pure deflagration scenarios; however, significant modifications are required in the density function of the inner ejecta and in the chemical profiles of the outermost regions. The constrained physical characteristics, such as the photospheric velocities and the time of maximum light, are also consistent with other SNe Iax. Despite being small in numbers, intermediate-luminosity Type Iax SNe are not outliers in the subclass but demonstrate the continuous nature of SNe Iax through their luminosity range. Following this observation, we argue that all SNe Iax share the same progenitor and explosion origin. r