A lot of the pics of this galaxy were from The Hubble, and surprisingly they got some help from an amateur astronomer.  Messier 106 is particularly mysterious for a number of reasons:

Located a little over 20 million light-years away, practically a neighbor by galactic standards, Messier 106 is one of the brightest and nearest spiral galaxies to our Milky Way. Although it may not look particularly unique, some of its features have baffled astronomers for years.

Here is a bit more on one of the mysteries.  It is surprisingly different than what we would have expected to see from a galaxy like this one:

Messier 106 has a supermassive black hole at its centre. Although this is true for most galaxies, this black hole is particularly active and hungry, gobbling up nearby material at a startling rate.

This huge black hole’s bottomless appetite is behind much of the galaxy’s unusual behavior. Messier 106 appears to be emitting powerful radiation from its centre — something we do not see with our Milky Way or other similar spirals. This is caused by the very active black hole at the galaxy’s centre, which violently drags gas and dust inwards. This material heats up, emitting bright microwave and X-ray radiation as it does so.

What do you think the reason for this massive black hole might be?  Feel free to comment with your theories!