First, the image, captured by famous group of astro-photographers Jean Claude Canonne, Nicolas Outters, Philippe Bernhard, Didier Chaplain and Laurent Bourgon (see their web sites www.cielboreal.com and www.cielaustral.com), is beautiful astro-photograph, exceptionally sharp, deep and detailed, showing the silhouette of the dark interstellar dust lanes on the background of billions of stars belonging to the Centaurus A galaxy with unprecedented details.

But Centaurus A is interesting also from astrophysical point of view. This galaxy is a source of intense radio emission (this is how the designation “Centaurus A” originated – it identifies a source of radio signals in the constellation Centaurus). Now we know there is a super-massive black hole in the galaxy center. The black hole attracts surrounding material, which spirals inward to its event horizon and creates so-called accretion disk. The matter within accretion disk is accelerated to insane speeds, reaching significant fractions of the speed of light. Mutual collisions of such fast-moving matter generate huge amount of energy, heating material inside the accretion disk. As the disk itself block the escape path, energy can radiate only through its poles. Radio images clearly show two jets of material, ejected from the accretion disk poles, both much longer than the galaxy itself.

And here comes the second unique quality of this image. In addition to almost 15 hours of classical LRGB exposures, revealing the galaxy in real colors, authors added almost 28 hours on narrow-band Hα exposures (shown in deep-red color), which reveal the hydrogen light of the jet, escaping from the close proximity of the super-massive black hole.

Image was acquired using the G4-16000 camera on CDK20 telescope.