... emission[*]
Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech Republic and Poland, and with the participation of Russia and the USA. 
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... region[*]
To obtain the effective exposure time, the exposure has to bedivided by the effective area at 511 keV of about 75 cm2. 
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... profile[*]
In a preliminary analysis in which we treated a much smaller dataset, systematic background uncertainties suggested a significant elongation of the galactic centre bulge emission along the galactic plane. This elongation was artificial and had been produced by background variations that were not fully explained by our model. Removing the short period of data with the strongest background variations removed also the apparent elongation of the bulge emission. 
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... level[*]
Using the quoted RMLRs, the formal significance of the disk emission amounts only to $2{-}3\sigma$. However, the tabulated RMLRs have been obtained using the ORBIT-DETE background model which is less sensitive to 511 keV line emission than the DETE model. Using the procedure outlined in Sect. 3 we reduce the flux uncertainties and increase the detection significance to  $3{-}4\sigma$. 
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... disk[*]
The difference between bulge-to-disk flux and luminosity ratio is only important for our home Galaxy and is related to the fact that the Sun is located within the galactic radius. For external galaxies this difference disappears since their bulge and disk appear at the same distance to us. 
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... SPI data[*]
Given the angular resolution of SPI, compact sources with an extent $\sim $ $1\ensuremath{^\circ} {-}2\ensuremath{^\circ} $ would be considered as point sources in this context. 
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...$\sim $1[*]
We note that, independently, large B/D ratios are also favoured by microlensing surveys towards the galactic bulge region (Binney & Evans 2001). 
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Copyright ESO 2005