The physical properties of T Pyx as measured by MUSE. I. The geometrical distribution of the ejecta and the distance to the remnant

Abstract

T Pyx is one of the most enigmatic recurrent novae, and it has been proposed as a potential Galactic type-Ia supernova progenitor. Using spatially resolved data obtained with MUSE, we characterized the geometrical distribution of the material expelled in previous outbursts surrounding the white dwarf progenitor. We used a 3D model for the ejecta to determine the geometric distribution of the extended remnant. We also calculated the nebular parallax distance ($d = 3.55 0.77$ kpc) based on the measured velocity and spatial shift of the 2011 bipolar ejecta. Our findings confirm previous results, including the data from the GAIA mission. The remnant of T Pyx can be described by a two-component model consisting of a tilted ring at $i = 63.7$ relative to its normal vector and fast bipolar ejecta perpendicular to the plane of the equatorial ring. We found an upper limit for the bipolar outflow ejected mass in 2011 of the bipolar outflow of $M_ ej,b $ M$_ odot $, which is lower than previous estimates given in the literature. However, only a detailed physical study of the equatorial component can provide an accurate estimate of the total ejecta of the last outburst, a fundamental step to understanding if T Pyx will end its life as a type-Ia supernova.