http://arxiv.org/abs/2206.01855
We use the {\it Gaia} EDR3 to explore the Galactic supernova remnant SNR G272.2-3.2, produced by the explosion of a Type Ia supernova (SNIa), about 7,500 years ago, to search for a surviving companion. From the abundances in the SNR ejecta, G272.2-3.2 is a normal SNIa.
The {\it Gaia} parallaxes allow to select the stars located within the estimated distance range of the SNR, and the {\it Gaia} proper motions to study their kinematics. From the {\it Gaia} EDR3 photometry, we construct the HR diagram of the selected sample, which we compare with the theoretical predictions for the evolution of possible star companions of SNIa. We can discard several proposed types of companions by combining kinematics and photometry. We focus our study on the kinematically most peculiar star, {\it Gaia} EDR3 5323900215411075328 (hereafter MV-G272), is a very clear outlier in the motion along the Galactic plane, both as compared with the sample and with the Besan\c{c}on model of the Galaxy. Its trajectory on the sky locates it at the center of the SNR, 6,000–8,000 years ago, which constitutes a unique characteristic among the 3,082 stars in the sample. Spectra have been obtained allowing a stellar parameters determination and a chemical abundance analysis. The star now appears as an M1-M2 dwarf. Its chemistry is consistent with that of a M dwarf companion, where a deep convective envelope could have diluted the material captured from the SN ejecta. We have also explored a wide area around the SNR, looking for a possible hypervelocity star ejected by the SN explosion. None has been found.
In conclusion, we have a candidate to be the surviving companion of the SNIa that resulted in SNR G272.2-3.2. It is supported by all its kinematical characteristics and by its trajectory within the SNR. This opens the possibility for SNe Ia originating in binary systems with a M-dwarf mass donor.
P. Ruiz-Lapuente, J. Hernández, R. Cartier, et. al.
Tue, 7 Jun 22
36/70
Comments: 33 pages, 19 Figures, 4 Tables, submitted to ApJ. Comments welcome