NGC 4945 Seyfert Galaxy


clic for 29% size 1010 x 673 (291 kB)

clic here for 42% size 1684 x 1122 (432 kB)

clic here for 70% size 2806 x 1870 (990 kB)

About this Image

NGC 4945 is a barred nearly edge-on spiral galaxy in the constellation Centaurus. It is thought to be quite similar to the Milky Way Galaxy, but X-ray observations show that NGC 4945 has an unusual, energetic, Seyfert 2 nucleus that might house a large black hole. It was discovered by James Dunlop in 1826.

These galaxies are now understood as experiencing vigorous star formation, from follow-up observations at optical and other wavelengths. Understanding this star formation at both high and low redshifts, and its relation to possible nuclear activity in these galaxies, is currently an important astronomical problem. The nuclear activity in galaxies is thought to be due to accretion by a supermassive central black hole. It is a prime example of a nearby luminous galaxy. Prominent dust lanes can be seen along the central bar of this spiral galaxy also reddening the major part of the galaxy. This apparent asymmetry is a geometric effect, as the dust lanes lie along the leading edge of the bar and along the trailing edge of the spiral arms; at the point of galactic corotation, where the arms join the bar, the dust lanes switch sides.
The nucleus of NGC 4945 is the brightest infrared source in the south, after the Magellanic Clouds.
NGC 4945 is a member of the Centaurus A / M 83 Group, a large, nearby group of galaxies.
North is to the right.

Compare an ESO image of this galaxy and further information on this object: here.
Literature about the Active Nucleus of NGC 4945: 1.

Technical Details


20 " Keller cassegrain in corrected secondary focus at f/9

Mount Liebscher GEM
Camera SBIG STL-11000M at -15C, 8-pos STL filter wheel
Filters Baader LRGB
Date Apr 28, 2008
Location IAS/Hakos Namibia
Sky Conditions dark skies, raw FWHM 1.3-1.8" temperature 15 C,
Exposure L:R:G:B = 30:30:30:30 minutes (10-minute sub-exposures);
all 1x1.
Programs used Maxim DL 4.5;
Photoshop CS3