Technical details:
Location / Date: Outside of Ramnäs, Västmanland, Sweden / 2015-February
Optics: Skywatcher Explorer 190MN
Mount: 10 Micron GM1000 HPS (Unguided)
Camera: Canon EOS 100D (Modded with Baader ACF filter)
Exposure: 40x 300 seconds, all shot on ISO 3200 (cumulative exposure time is 3 hours and 20 minutes)
Processing: Pixinsight and Photoshop
Image details:
Messier 106 (also known as NGC 4258) is a spiral galaxy in the constellation Canes Venatici.
It was discovered by Pierre Méchain in 1781.
M106 is at a distance of about 22 to 25 million light-years away from Earth.
It is also a Seyfert II galaxy.
Due to x-rays and unusual emission lines detected, it is suspected that part of the galaxy is falling into a supermassive black hole in the center.
NGC 4217 is a possible companion galaxy of Messier 106.
M106 has a water vapor megamaser (the equivalent of a laser operating in microwave instead of visible light and on a galactic scale)
that is seen by the 22-GHz line of ortho-H2O that evidences dense and warm molecular gas. These water vapors give M106 its characteristic purple color. (Information from Wikipedia)