A comparison between the original Hubble image and processing, and the processing of the Hubble data made by Daniel Nobre:
NASA, ESA and the Hubble Heritage Team (STScI/AURA).
Acknowledgement: J. Gallagher and P. Puxley.
M82. NASA, ESA, Hubble;
Processing & Copyright: Daniel Nobre
The difference between the two versions of the picture is that the "body" of M82 is darker blue in Daniel Nobre's picture, and, more importantly, Daniel Nobre's picture appears to show us sites of recent star formation and massive clusters. Note the bright yellowish patch in Nobre's picture, which clearly suggests the presence of massive young clusters, and the bright blue patches to the left of the massive red outflows. These light blue patches again suggests that massive young clusters are present.
However, I believe that M82 is almost completely devoid of star formation except in the center, where a brilliant starburst is taking place. As the APOD caption said, it is this starburst that is fuelling the massive gaseous outflows from the center of M82.
To show you why I don't think that M82 has any star formation to speak of outside of its center, take a look at
the GALEX image below of M82. Blue colors in GALEX images mean the presence of far ultraviolet light; yellow colors mean near ultraviolet light usually generated by intermediate-temperature stars of spectral classes F, G and K.
Take a look at M82 and note the all-yellow color of the "body" of the galaxy. The red outflows from the galaxy look blue in the GALEX image, because ultraviolet light is also present in the outflows. Admittedly the three light blue blobs to the left of the outflows that stand out so clearly in Daniel Nobre's image can also be seen in the GALEX picture, now as three (or four) yellow blobs. They
might be young clusters, so reddened by dust that they look like old stars in the GALEX image. Just as likely though, they might be "
Baade's Windows", regions of the disk of M82 where there is comparatively little dust, and where the (old) stellar population shows up better.
My point is that I think that the violent outflows of gas from the center of M82, driven by the extreme star formation in the center of that galaxy, is depleting the galaxy of gas and preventing future star formation.
One more note: The caption of the APOD said that the outflows of M82 are over 10.000 light-years long. But if the outflows are 10,000 light-years long, and they appear to be almost as long as the galaxy itself, then I have to wonder how small M82 really is.
Ann