Earlier observations of NGC 1808 in various wavebands ( X-ray , optical , near-infrared , radio ) provided evidence for the existence of either a starburst or a Seyfert 2 nucleus .
We here present the results of multiwavelength XMM-Newton and Chandra observations , which directly prove the co-existence of thermal diffuse plasma and non-nuclear unresolved point-like sources associated with the starburst activity , along with a Low Luminosity Active Galactic Nucleus ( LLAGN ) or an Ultra Luminous X-ray source ( ULX ) .
The broad bandwidth of XMM-Newton allows us to show that the unresolved nuclear source in NGC 1808 dominates the hard X-ray spectrum , while the emission in the soft regime , below 1 keV , is dominated by a thermal component associated to an extended starburst .
Both EPIC and RGS data provide reliable detections of a number of emission lines from heavy elements , with abundances ranging from roughly 0.7 to 2.2 Z _ { \odot } for different elements .
However , no 6.4 keV Fe K \alpha fluorescence line emission was detected .
The analysis of the nuclear region of NGC 1808 allows us to detect and disentangle the contribution of an unresolved nuclear X-ray source and the starburst region , but the exact nature of the nucleus remains unknown .
The observed luminosity of NGC 1808 is L _ { 2 - 10 keV } = ( 1.61 \pm 0.06 ) \times 10 ^ { 40 } erg s ^ { -1 } .
A comparison of our OM 212 nm image with a CTIO 4-m telescope H \alpha frame shows a good general correspondence between the emission from massive stars and warm ionized gas , with minor deviations near the ends of the bar in NGC 1808 .
An aditional , very soft thermal spectral component with kT \simeq 0.1 keV has been discovered in the XMM-Newton spectral analysis , which most likely originates from the halo of NGC 1808 .