SIMBAD references

We have compiled a complete extragalactic sample based on ∼25,000 deg² to a limiting flux of 3x10^–11 ergs/cm2/s (∼7000 deg² to a flux limit of 10^–11 ergs/cm2/s) in the 20-40 keV band with INTEGRAL. We have constructed a detailed exposure map to compensate for effects of nonuniform exposure. The flux-number relation is best described by a power law with a slope of α=1.66±0.11. The integration of the cumulative flux per unit area leads to f_20-40 keV_=2.6x10^–10 ergs/cm2/s/sr, which is about 1% of the known 20-40 keV X-ray background. We present the first luminosity function of AGNs in the 20-40 keV energy range, based on 38 extragalactic objects detected by the imager IBIS-ISGRI on board INTEGRAL. The luminosity function shows a smoothly connected double-power-law form with an index of γ₁=0.8 below and γ₂=2.1 above the turnover luminosity of L_*=2.4x10⁴³ ergs/s. The emissivity of all INTEGRAL AGNs per unit volume is W_20–40keV(>10⁴¹ ergs/s)=2.8x10³⁸ ergs/s h³₇₀Mpc^–3. These results are consistent with those derived in the 2-20 keV energy band and do not show a significant contribution by Compton-thick objects. Because the sample used in this study is truly local (z{d1}=0.022), only limited conclusions can be drawn for the evolution of AGNs in this energy band.