Millimeter Observations of the Type II SN 2023ixf: Constraints on the Proximate Circumstellar Medium

We present 1.3 mm (230 GHz) observations of the recent and nearby Type II supernova, SN2023ixf, obtained with Submillimeter Array (SMA) at 2.6-18.6 days after explosion. The were as part SMA Large Program POETS (Pursuit Extragalactic Transients SMA). do not detect any emission location deepest limits $L_\nu(230\,{\rm GHz})\lesssim 8.6\times 10^{25}$ erg s$^{-1}$ Hz$^{-1}$ 2.7 7.7 days, 3.4\times 18.6 days. These are about a factor 2 times dimmer than from SN2011dh (IIb), an order magnitude compared to SN1993J (IIb) SN2018ivc (IIL), 30 most luminous non-relativistic SNe in mm-band (Type IIb/Ib/Ic). Using these context analytical models that include synchrotron self-absorption free-free absorption we place constraints on proximate circumstellar medium around progenitor star, scale $\sim 2\times 10^{15}$ cm, excluding range $\dot{M}\sim {\rm few}\times 10^{-6}-10^{-2}$ M$_\odot$ yr$^{-1}$ (for wind velocity, $v_w=115$ km s$^{-1}$, ejecta $v_{\rm eje}\sim (1-2)\times 10^4$ s$^{-1}$). results consistent inference mass loss rate based optical spectroscopy ($\sim 10^{-2}$ for s$^{-1}$), but tension hard X-rays 7\times 10^{-4}$ This may be alleviated by non-homogeneous confined CSM, high-resolution spectroscopy.