Intermediate luminosity type Iax supernova 2019muj with narrow absorption lines: Long-lasting radiation associated with a possible bound remnant predicted by the weak deflagration model

We present comprehensive spectroscopic and photometric analyses of the intermediate luminosity type Iax supernova (SN Iax) 2019muj based on multi-band datasets observed through the framework of the OISTER target-of-opportunity program. SN 2019muj exhibits almost identical characteristics to the subluminous SNe Iax 2008ha and 2010ae in terms of the observed spectral features and the light curve evo...