Constraints on the sub-pc environment of the nearby Type Iax SN 2014dt from deep X-ray and radio observations

ABSTRACT We present X-ray and radio observations of what may be the closest Type Iax supernova (SN) to date, SN 2014dt (d = 12.3–19.3 Mpc), provide tight constraints on emission. infer a specific luminosity $L_R\lt (1.0\!-\!2.4)\times 10^{25}\, \rm {erg\, s^{-1}\, Hz^{-1}}$ at frequency 7.5 GHz $L_X\lt 1.4\times 10^{38}\, s^{-1}}$ (0.3–10 keV) ∼38–48 d post-explosion. interpret these limits in context Inverse Compton (IC) emission synchrotron from population electrons accelerated forward shock explosion power-law distribution $N_e(\gamma _e)\propto \gamma _e^{-p}$ with p 3. Our analysis constrains progenitor system mass-loss rate $\dot{M}\lt 5.0 \times 10^{-6} {M_{\odot }\, yr^{-1}}$ distances $r\lesssim 10^{16}\, {cm}$ for an assumed wind velocity $v_w=100\, {km\, s^{-1}}$, fraction post-shock energy into magnetic fields relativistic ϵB 0.01 ϵe 0.1, respectively. This result rules out some parameter space symbiotic giant star companions, it is consistent low rates expected He-star companions. calculations also show that improved sensitivity next-generation Very Large Array (ngVLA) needed probe very low-density media characteristic He stars are leading model binary stellar companions white dwarfs giving origin SNe.