NGC 4945

NGC4945-SLHa-RGB-05-Final9-cC

Click on the image for a larger version

NGC 4945 is a barred spiral galaxy seen nearly edge-on. For its dust lanes and angle of inclination respect our line of vision, it reminds us of NGC 253 (although they have no physical relationship other than their aspect…). NGC 4945 is located in the constellation Centaurus, about 4 degrees Southeast of NGC 5139  (Omega Centauri) and belongs to the Centaurus A Group (as well as M83) being its second brightest member. This a quite active galaxy, classified as type Seyfert 2. Actually, it has a supermassive black hole in its center (with a mass about 1.5 million solar masses) that is unusually active. Quite recently, in October 2017, R. Wojaczynski and A. Niedzwiecki studied the ratio X-ray to Gamma-ray from the output radiation coming out from the center of the galaxy and proposed that the large variation in luminosity (X-ray) and spectrum (Gamma-ray) of these energetic emissions was due to the large accretion disk present around the black hole, eventually collapsing to the center (most probably, only partially). This image has been taken in LRHaGB.

 

Additional Information

Object

Name(s): NGC 4945

Type: Barred Spiral Galaxy

RA:  13h 05m 25s

Dec: -49º 27’ 39”

Constellation: Centaurus

Size (arcmin): 20×4

Magnitude: +8.4

Distance: 11 Mly

Image

Date: 2018-02-18 thru 2018-03-17

Location: iTelescope.net, SSO near Coonabarabran, NSW Australia

Size (arcmin): 24×19

Telescope: Planewave CDK 20” f/6.8

Camera: SBIG STX16803 (4096x4096pix)

Guiding: Astrodon MonsterMOAG off-axis guider

Total exposure: 18h 45m (Ha: 4h; L: 6h 15m; RGB: 8h 30m)

Processing: CCDStack, Photoshop CC 2018

%d bloggers like this: