SIMBAD references

The first set of compact sources observed in the ISOPHOT 170µm Serendipity Survey is presented. From the slew data with low (I_100µm≤15MJy/sr) cirrus background, 115 well-observed sources with a high signal-to-noise ratio in all detector pixels having a galaxy association were extracted. Of the galaxies with known optical morphologies, the vast majority are classified as spirals, barred spirals, or irregulars. The 170µm fluxes measured from the Serendipity slews have been put on an absolute flux level by using calibration sources observed additionally with the photometric mapping mode of ISOPHOT. For all but a few galaxies, the 170µm fluxes are determined for the first time, which represents a significant increase in the number of galaxies with measured Far-Infrared (FIR) fluxes beyond the IRAS 100µm limit. The 170µm fluxes cover the range 2≲F_170µm≲100Jy. Formulae for the integrated FIR fluxes F_40–220µm and the total infrared fluxes F_1–1000µm incorporating the new 170µm fluxes are provided. The large fraction of sources with a high F_170µm/F_100µm flux ratio indicates that a cold (T_Dust≲20K) dust component is present in many galaxies. The detection of such a cold dust component is crucial for the determination of the total dust mass in galaxies, and, in cases with a large F_170µm/F_100µm flux ratio, increases the dust mass by a significant factor. The typical mass of the coldest dust component is M_Dust=10^7.5±0.5M_☉, a factor 2-10 larger than that derived from IRAS fluxes alone. As a consequence, the majority of the derived gas-to-dust ratios are much closer to the canonical value of ≃160 for the Milky Way. By relaxing the selection criteria, it is expected that the Serendipity Survey will eventually lead to a catalog of 170µm fluxes for ≃1000 galaxies.