Table 3: Event rate N and energy E for each object, with the $C_{\lambda }=0$ , and $C_{\lambda }=L_\lambda ^{{\rm min}}$ assumptions.
Name N E N E

(year^-1) ( $\times 10^{50}$ erg) (year^-1) ( $\times 10^{50}$ erg)

$C_{\lambda }=0$ $C_{\lambda }=L_\lambda ^{{\rm min}}$

Mrk 335 $160.76 \pm 123.78$ $0.25 \pm 0.26$ $17.82 \pm 41.22$ $0.72 \pm 0.76$

Mrk 509 $39.28 \pm 31.89$ $2.03 \pm 0.67$ $9.09 \pm 15.34$ $5.08 \pm 1.64$

Mrk 926 $24.84 \pm 17.20$ $3.94 \pm 0.87$ $14.66 \pm 13.22$ $6.12 \pm 1.30$

Mrk 1095 $149.32 \pm 90.68$ $0.26 \pm 0.08$ $18.45 \pm 31.88$ $0.99 \pm 0.35$

NGC 3516 $104.90 \pm 23.42$ $0.024 \pm 0.002$ $75.44 \pm 19.86$ $0.037 \pm0.004$

NGC 3783 $50.11 \pm 48.48$ $0.08 \pm 0.02$ $28.21 \pm 36.37$ $0.11 \pm 0.03$

NGC 4151 $32.12 \pm 8.62$ $0.05 \pm 0.002$ $31.16 \pm 8.49$ $0.056 \pm0.002$

NGC 4593 $10.32 \pm 7.09$ $0.08 \pm 0.02$ $2.32 \pm 3.36$ $0.19 \pm 0.05$

NGC 5548 $51.59 \pm 18.49$ $0.20 \pm 0.03$ $29.52 \pm 13.99$ $0.30 \pm 0.05$

NGC 7469 $1133.8 \pm 543.73$ $0.02 \pm 0.01$ $269.88 \pm 265.39$ $0.04 \pm 0.02$

3C 120.0 $27.53 \pm 12.42$ $0.45 \pm 0.48$ $13.22 \pm 8.61$ $0.65 \pm0.67$

3C 273 $62.44 \pm 14.51$ $71.20\pm 27.34$ $10.24 \pm 5.88$ $189.62 \pm53.83$

3C 390.3 $8.94 \pm 4.82$ $1.64 \pm 0.49$ $5.86 \pm 3.90$ $2.49 \pm 0.78$

Fairall 9 $8.82 \pm 6.44$ $11.11 \pm 1.49$ $6.50 \pm 5.53$ $13.03 \pm1.74$

ESO 141-55 $9.75 \pm 5.11$ $9.38 \pm 1.85$ $2.69 \pm 2.69$ $20.03 \pm 3.86$

**Table 3:** Event rate N and energy E for each object, with the $C_{\lambda }=0$ , and $C_{\lambda }=L_\lambda ^{{\rm min}}$ assumptions.
Name	N	E	N	E
	(year^-1)	( $\times 10^{50}$ erg)	(year^-1)	( $\times 10^{50}$ erg)
	$C_{\lambda }=0$	$C_{\lambda }=L_\lambda ^{{\rm min}}$
Mrk 335	$160.76 \pm 123.78$	$0.25 \pm 0.26$	$17.82 \pm 41.22$	$0.72 \pm 0.76$
Mrk 509	$39.28 \pm 31.89$	$2.03 \pm 0.67$	$9.09 \pm 15.34$	$5.08 \pm 1.64$
Mrk 926	$24.84 \pm 17.20$	$3.94 \pm 0.87$	$14.66 \pm 13.22$	$6.12 \pm 1.30$
Mrk 1095	$149.32 \pm 90.68$	$0.26 \pm 0.08$	$18.45 \pm 31.88$	$0.99 \pm 0.35$
NGC 3516	$104.90 \pm 23.42$	$0.024 \pm 0.002$	$75.44 \pm 19.86$	$0.037 \pm0.004$
NGC 3783	$50.11 \pm 48.48$	$0.08 \pm 0.02$	$28.21 \pm 36.37$	$0.11 \pm 0.03$
NGC 4151	$32.12 \pm 8.62$	$0.05 \pm 0.002$	$31.16 \pm 8.49$	$0.056 \pm0.002$
NGC 4593	$10.32 \pm 7.09$	$0.08 \pm 0.02$	$2.32 \pm 3.36$	$0.19 \pm 0.05$
NGC 5548	$51.59 \pm 18.49$	$0.20 \pm 0.03$	$29.52 \pm 13.99$	$0.30 \pm 0.05$
NGC 7469	$1133.8 \pm 543.73$	$0.02 \pm 0.01$	$269.88 \pm 265.39$	$0.04 \pm 0.02$
3C 120.0	$27.53 \pm 12.42$	$0.45 \pm 0.48$	$13.22 \pm 8.61$	$0.65 \pm0.67$
3C 273	$62.44 \pm 14.51$	$71.20\pm 27.34$	$10.24 \pm 5.88$	$189.62 \pm53.83$
3C 390.3	$8.94 \pm 4.82$	$1.64 \pm 0.49$	$5.86 \pm 3.90$	$2.49 \pm 0.78$
Fairall 9	$8.82 \pm 6.44$	$11.11 \pm 1.49$	$6.50 \pm 5.53$	$13.03 \pm1.74$
ESO 141-55	$9.75 \pm 5.11$	$9.38 \pm 1.85$	$2.69 \pm 2.69$	$20.03 \pm 3.86$

Source LaTeX | All tables | In the text

	1 Introduction
	2 The concept of discrete-event model
	3 The IUE light curves
	4 Temporal analysis
	5 Interpretation in terms of discrete-event model
	6 Discussion
	7 Conclusion
	References
	Online Material
	Appendix A: Structure functions 1300-3000 Å