Experiments with MUSE data: Finding SN remnants & other curious sources

One of the ways of following up on the success story of CALIFA is to refine the spatial resolution, and MUSE is the tool for that. Its superb image quality allows for a different kind of science. While browsing through emission line images derived from MUSE datacubes, we have spotted a number of compact-looking sources with forbidden line emission ([OIII], [NII], [SII]) in excess of that typical of HII regions. NGC 4030, a late type spiral 30 Mpc away, was picked as a case study. This seminar reports our efforts to detect, isolate and identify the nature of these objects. We find that a variant of the PCA-tomography technique allows a clean detection of these unidentified sources, though extracting their spectra out of the highly inhomogeneous emission line background is challenging. We focus on a list of 26 sources for which the extraction process works best, although the true population of these sources is much larger. We find that ~ half of this sample exhibits unequivocal spectral signatures of supernova remnants (SNR) around 7300 A, and a stacking analysis shows that the same features are also present, except weaker, in many other cases. At nearly 30 Mpc, these are probably the most distant SNRs detected by optical means to date. A peculiar luminous, blue, and variable (hence a LBV?) source is also found. Application of the same techniques to the MUSE archive should reveal many more objects like these.