ISAAC spectrum of the central region of NGC 1808

This image is a reproduction of a long-slit ISAAC spectrum of the central region of the active galaxy NGC 1808. It is in the 2.3 µm spectral region and the wavelength increases towards right. Several strong, vertical bands are seen; they are caused by CO-molecules in the atmospheres of the stars in this area. The bright band at the centre corresponds to the nucleus of the galaxy within which the central black hole is located. The characteristic S-shape is a result of the rotation of the stars around this centre, due to the Doppler effect.

Technical information: this image shows a raw, long-slit IR-spectrum in the 2.3 µm wavelength region, obtained with ISAAC along the major axis of this galaxy.