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## B. Non-blazar AGNs and Blazars 

As can be seen in Fig. 3, the spectrum of the cos- mic MeV background connects smoothly with that of the cosmic X-ray background (CXB), while the spec- tral index of the EGRB changes abruptly around ∼ 10 MeV. This indicates that the sources of the EGRB below 10 MeV is the same population as that of the CXB (i.e. non-blazar AGNs), and the sources of the EGRB above 10 MeV is a different population (i.e. blazars). 

Recently, based on observations of Swift/BAT- selected blazars at 15–55 keV, Ref. [29] suggested that MeV blazars contribute significantly to the MeV background. However, this conclusion is based on an extrapolation of blazar SEDs from 55 keV to the MeV band, and some fine tuning may be required in the MeV blazar SED to reproduce the EGRB spec- trum that connects smoothly with the CXB. More- over, the spectral break in the EGRB around 10 MeV implies that such MeV blazars are a distinct popula- tion from those contributing to the EGRB above 10 MeV. Therefore, it seems more natural that the dom- inant contribution to the MeV background is coming from non-blazar AGNs as proposed by [28]. Further observational studies are desired to reveal the true ori- gin of the MeV background. 

## V. PREDICTIONS FOR THE FERMI MISSION 

## A. Expected Number of Blazars and Non-blazar AGNs 

The left panel of Figure 4 shows the cumulative dis- tribution of > 100 MeV photon flux of blazars, non- blazar AGNs, and the total of the two. The GLF predicts that about 750 and 1200 blazars should be detected by Fermi where we assumed the Fermi sensi- tivity to be F lim = 3 × 10 $_{−}$9 and 1 × 10 $_{−}$9 photons cm $_{−}$2 s $_{−}$1 above 100 MeV. These sensitivities correspond to ∼ 1 and ∼ 5 years survey sensitivities. 

The model of Ref. [11], and the PLE and LDDE models [6] predicted ∼ 10000, 5000, and 3000 blazars for the 1-year sensitivity limit, respectively. It is re- markable that the GLF models in this work predict significantly smaller numbers of blazars than most of previous studies. 

About 4–50 non-blazar AGNs would be detected 

