The "shell" is not unexpected in the PC model, the various plasma layers of the Earth's and Sun's EM fields (like layers of an onion) show this is an expected result of plasma interactions. The scalability of EM plasma interactions suggests that the galaxy's EM field will be a larger version of the solar EM field and so on down to the atomic structure.
This finding is not so surprising. For example, Andromeda galaxy exhibits some shell around its core, which is quite apparent in X-ray spectrum. And the Milky Way galaxy - which is younger but otherwise quite similar to Andromeda - will not be very different. Many findings are quite easy if you know where to look for it - so you should be informed first.
The shell in many galaxies represents the shock or bow wave, resulting from less or more apparent activity of their core. I presume, even seemingly quiet galactic centers may ejects less or more steady jets of neutrinos, which do annihilate with CMBR background and interstellar gas around galaxy and which are forming less or more compact halo or sphere of newly created particles there.
Errata: IMO Milky Way is older - not younger - than the Andromeda galaxy, which is rather fresh product of galactic merger in addition.
Note that the shell of Andromeda galaxy exhibits dodecahedral structure composed of adjacent voids like the cluster of foam bubbles. It would indicate, that central black holes exhibits whole bundle of neutrino jets or that the dark matter around it exhibits cohesive foam behavior. In my model the activity of central black holes ceases gradually and the active galactic nuclei is losing one its jets one after another.
reveal nothing more than instrumental artifacts resulting from the (inaccurate) assembly of X-ray mosaics from early XMM-Newton data (i.e. they do not correspond to real XR structures in M31). Compare those images to properly callibrated XR mosaics of M31 from both XMM and Chandra data(see Fig 1):
The shell structure detected in this study is stellar in nature and similar to stellar shells/ripples detected in many galaxies suspected of undergoing a past merger(i.e. http://apod.nasa....226.html ).
"...Andromeda galaxy exhibits some shell around its core, which is quite apparent in X-ray spectrum."
To reiterate, this current study discusses a shell of stars discovered some 24kpc from the galactic center of the Milky Way Galaxy and not a fictitious XR shell within a kpc of the nucleus of M31: http://arxiv.org/abs/1302.5111
Antiscientists (there is no "PC model" qualifying as science, and so such comments doesn't belong on science sites) and sockpuppetry. WWES - what would Einstein say?
cantdrive85
Feb 21, 2013