SN 2022xlp: The second-known well-observed, intermediate-luminosity Iax supernova

Context. We present a detailed multicolor photometric and spectroscopic analysis of type Iax supernova SN 2022xlp. With a V-band absolute magnitude light curve peaking at Mmax(V) = − 16.04 ± 0.25 mag, this object is regarded as the second determined well-observed Iax supernova in the intermediate luminosity range after SN 2019muj. Aims. Our research aims to explore the question of whether the physical properties vary continuously across the entire luminosity range. We also investigate the chemical abundance profiles and the characteristic physical quantities of the ejecta, followed by tests of the predictions of hydro simulations. Methods. The pseudo-bolometric light curve was calculated using optical (BgVriz) and UV (Swift UVOT UVW2,UVM2, UVW1,U,B) light curves and fits with a radiation diffusion Arnett model to constrain the average optical opacity, ejected mass, and initial nickel mass produced in the explosion. We analyzed the color evolution of SN 2022xlp and compared it with that of other Iax supernovae with different peak luminosities. We used the spectral tomography method to determine the radial profiles of physical properties and abundances of the ejecta, comparing them with a set of hydrodynamic pure deflagration models. Results. SN 2022xlp shows a relatively rapid color evolution due to the decreasing photospheric temperature in the early phase. The estimated bolometric flux peaks at 8.87 × 1041 erg s−1 and indicates the production of radioactive nickel as M(56Ni) = 0.0215 ± 0.009 M⊙. According to the best-fit model, the explosion energy is (2.066 ± 0.236)×1049 erg and the ejecta mass is 0.142 ± 0.015 M⊙. The performed spectral tomography analysis shows that the determined physical quantities agree well with the predictions of the deflagration simulations, with modifications regarding the increased Na abundance and the more massive outer layers. SN 2022xlp bridges the previously existing luminosity gap, together with SN 2019muj, and supports the assumption of continuous variation in the physical properties across the SN Iax subclass.