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

Context. T Pyx is one of the most enigmatic recurrent novae, and it has been proposed as a potential Galactic type-Ia supernova progenitor.
Aims: Using spatially resolved data obtained with MUSE, we characterized the geometrical distribution of the material expelled in previous outbursts surrounding the white dwarf progenitor.
Methods: 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.
Results: 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.
Conclusions: We found an upper limit for the bipolar outflow ejected mass in 2011 of the bipolar outflow of M_{ej, b} < (3.0 ± 1.0)×10⁻⁶ M_⊙, 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.

The MUSE datacubes are available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (ftp://130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/686/A72