This is a deep narrowband image using H-a + [NII] mapped to red and OIII mapped to blue/green. Star colors were added with shorter RGB data. The image is filled with a variety of objects and elongated tendrils, showing the complexity of this region.
Signal contours for X-Ray (C. Goudis and J. Meaburn, “An Accurate Optical and Radio Comparison for the Puppis A Supernova Remnant”, Astron. Astrophys. 62, 283-285, 1978) and radio (R. Petre et al. “A High-Resolution X-Ray image of Puppis A: Inhomogeneities in the Interstellar Medium, Astron. J. 258, 22-30, July 1, 1982) data adapted from these technical references are superimposed upon my image below. The white contours are for the X-Ray data and green for radio data. The ‘X’ represents the centroid of the radio data. As the authors indicated, there are regions where the contours correspond to the brighter optical emissions, but there are also regions that do not.