Using Anisotropies as a Forensic Tool for Decoding Supernova Remnants by Abigail Polin et al. on Tuesday 29 November

We present a method for analyzing supernova remnants (SNRs) by diagnosing the

drivers responsible for structure at different angular scales. First, we

perform a suite of hydrodynamic models of the Rayleigh-Taylor instability (RTI)

as a supernova collides with its surrounding medium. Using these models we

demonstrate how power spectral analysis can be used to attribute which scales

in a SNR are driven by RTI and which must be caused by intrinsic asymmetries in

the initial explosion. We predict the power spectrum of turbulence driven by

RTI and identify a dominant angular mode which represents the largest scale

that efficiently grows via RTI. We find that this dominant mode relates to the

density scale height in the ejecta, and therefore reveals the density profile

of the SN ejecta. If there is significant structure in a SNR on angular scales

larger than this mode, then it is likely caused by anisotropies in the

explosion. Structure on angular scales smaller than the dominant mode exhibits

a steep scaling with wavenumber, possibly too steep to be consistent with a

turbulent cascade, and therefore might be determined by the saturation of RTI

at different length scales (although systematic 3D studies are needed to

investigate this). We also demonstrate, consistent with previous studies, that

this power spectrum is independent of the magnitude and length scales of

perturbations in the surrounding medium and therefore this diagnostic is

unaffected by ``clumpiness" in the CSM.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2209.02134v2