SIMBAD references

We compare a deep (37 ks) Chandra ACIS-S image of the M31 bulge to Local Group Survey narrowband optical data and Very Large Array (VLA) radio data of the same region. Our precisely registered images reveal two new optical shells with X-ray counterparts. These shells have sizes, [SII]/Hα flux ratios, and X-ray spectral properties typical of supernova remnants (SNRs) with ages of 9⁺³_–4and 17⁺⁶_–9kyr. Analysis of complementary VLA data reveals the radio counterparts, further confirming that they are SNRs. We discuss and compare the properties and morphologies of these SNRs at the different wavelengths.