Stellar sources in the ISOGAL intermediate bulge fields
Résumé
We present a study of ISOGAL sources in the ïntermediate\" galactic bulge ($|$$l$$|$ $<$ 2$^\\circ$, $|$$b$$|$ $\\sim$ 1$^\\circ$--4$^\\circ$), observed by ISOCAM at 7 and 15 $\\mu m$. In combination with near-infrared (I, J, K$_{\\rm s}$) data of DENIS survey, complemented by 2MASS data, we discuss the nature of the ISOGAL sources, their luminosities, the interstellar extinction and the mass-loss rates. A large fraction of the 1464 detected sources at 15 $\\mu m$ are AGB stars above the RGB tip, a number of them show an excess in ([7]-[15])$_{\\rm 0}$ and (K$_{\\rm s}$-[15])$_{\\rm 0}$ colours, characteristic of mass-loss. The latter, especially (K$_{\\rm s}$-[15])$_{\\rm 0}$, provide estimates of the mass-loss rates and show their distribution in the range 10$^{-8}$ to 10$^{-5}$ M$_{\\rm \\odot}$/yr.