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تسجيل مستخدم جديدThe European Large Area ISO Survey (ELAIS): Optical Identifications of 15 micron and 1.4 GHz sources in N1 and N2
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We present the optical identification of mid-IR and radio sources detected in the European Large Area ISO Survey (ELAIS) areas N1 and N2. Using the r band optical data from the Wide Field Survey we apply a likelihood ratio method to search for the counterparts of the 1056 and 691 sources detected at 15 micron and 1.4 GHz respectively, down to flux limits of S_{15}=0.5 mJy and S_{1.4 GHz}=0.135 mJy. We find that ~92% of the 15 micron ELAIS sources have an optical counterpart down to the magnitude limit of the optical data, r=24. All mid-IR sources with fluxes S_{15} >= 3 mJy have an optical counterpart. The magnitude distribution of the sources shows a well defined peak at relatively bright magnitudes r~18. About 20% of the identified sources show a point-like morphology; its magnitude distribution has a peak at fainter magnitudes than those of galaxies. The mid-IR-to-optical and radio-to-optical flux diagrams are presented and discussed in terms of actual galaxy models. Objects with mid-IR-to-optical fluxes larger than 1000 are found that can only be explained as highly obscured star forming galaxies or AGNs. Blank fields being 8% of the 15 micron sample have even larger ratios suggesting that they may be associated with higher redshift and higher obscured objects.
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The European Large Area ISO Survey (ELAIS) has surveyed 12 square degrees of the sky at 15 and 90 microns, and subsets of this area at 6.75 and 175 microns, using the Infrared Space Observatory (ISO). This project was the largest single open time pro
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