3.5. The Overall continuum spectral energy distribution
Having studied the emission components separately we can now put all
these elements together. To do so we present in
Fig. 8 the average
spectrum obtained by projecting all the data of
Fig. 1 onto the frequency axis.
Figure 8 also gives the
same data but in the form of
.
f versus
. It is striking that the flux
per logarithmic interval is nearly constant over more than ten decades
of frequency, another way of expressing that to the first order the
emission is proportional to
-1. In the second
order, it is striking to see two maxima in the
.
f versus
distribution at roughly the same level, one in the far ultraviolet and
the other at about 1MeV.
Integrating the spectrum one can deduce the total flux in the average
spectrum and the bolometric luminosity of 3C 273. One finds a total
flux of
1.9 . 10-9 ergs s-1cm-2 and
assuming
isotropic emission, H0 = 50km/(s Mpc),
= 1 and
q0 = 0.5 one finds a luminosity of
2.2 . 1047ergs s-1.
(Türler et al in preparation).
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Figure 8. Overall average spectrum of 3C 273 (first panel). This corresponds to a
projection onto the frequency axis of all data in
figure 1. The bottom
panel shows the same data as above but represented as
|