NGC 4151, 4145 Mosaic in Canes Venatici
This image shows the spiral galaxy NGC 4151 (Left), located at a distance of about 45 million light years from us. NGC 4151 is a Seyfert galaxy and hosts one of the brightest active galactic nuclei (AGN) known at X-ray wavelengths. The supermassive black hole lying at the centre of NGC 4151 has a mass of about 50 million solar masses.
NGC 4145 (Right) is around 44 million light years away and is part of the Ursa Major cluster of galaxies. This cluster contains many bright spirals for which NGC 4145 is a member. However this galaxy is considered relatively "anemic" due to the fact that unlike most spiral galaxies it does not have a lot of star formation taking place. While the spiral arms of this galaxy are punctuated by some activity, the rest of the galaxy is quite quiet. Indeed astronomers suggest that a galaxy like this will soon (in galactic terms) lose the impetus to form stars and settle down to become a lenticular galaxy. Interestingly this galaxy is interacting with another (NGC 4151). This may help maintain the star formation in NGC 4145. In fact close inspection of the nucleus of NGC 4145 seems to indicate that the tug of NGC 4151 has displaced it from its position in the center of NGC 4145.
Telescope: Planewave 24" f6.7 on a Planewave HD Mount Camera: SBIG 16803
Location: Stellar Winds Observatory at DSNM, Animas, New Mexico
Exposure: LRGB 450L, 240 each RGB for each panel of the mosaic