**Table A.1:** Comparison of the best fit parameters obtained using the standard matrix (ISDC) and the new A.S. version.
Parameter	OSA 4.2	A.S. Version	Other experiment
Crab nebula+pulsar: Power Law
$\alpha$	$2.19\pm0.03^*$	$2.09\pm0.03$	2.1
K (ph cm^-2 s^-1 KeV^-1)	$10.2\pm0.2^*$	$9.6\pm0.2$	9.7
$\chi ^2$ (d.o.f.)	5.6 (95)	1.3 (95)
			Ref. (1)
GX 1+4: Comptonization continuum model (COMPTT in XSPEC)
T₀ (keV)	1.27 (frozen)	1.27 (frozen)	1.27 ^+1.4_-1.1
$T_{\rm e}$ (keV)	$13.5\pm0.5$	$12.6\pm0.4$	10.3 ⁺¹³_-9
$\tau$	$2.7\pm0.1$	$3.3\pm0.2$	3.7 ⁺⁴_-3
K (ph cm^-2 s^-1 KeV^-1)	( $2.1\pm0.1)\times 10^{-2}$	( $1.9\pm0.1)\times 10^{-2}$	2.1 $^{+2.3}_{-1.8}\times 10^{-2}$
$\chi ^2$ (d.o.f.)	1.5 (58)	1.1 (58)
			Ref. (2)
Cygnus X1: Cut-off power law
$\alpha$	$1.66\pm0.04^*$	$1.45\pm0.04$	$1.45\pm0.01$
$E_{\rm c}$ (keV)	$158\pm12^*$	$122\pm7$	$162\pm9$
K (ph cm^-2 s^-1 KeV^-1)	$1.7\pm0.3^*$	$1.2\pm0.3$	$0.91\pm0.04$
$\chi ^2$ (d.o.f.)	3.2 (48)	1.9 (48)
			Ref. (3)
Sco X1: Bremstralung + Power law
KT (keV)	$4.2\pm0.1$	$4.3\pm0.1$	$4.51\pm0.08$
Flux $_{20-50 ~\rm keV}$ (erg cm^-2 s^-1)	( $5.5\pm0.3)\times 10^{-9}$	( $6.5\pm0.4)\times 10^{-9}$	( $7.4\pm0.6)\times 10^{-9}$
$\alpha$	$2.9\pm0.2$	$2.8\pm0.2$	$2.4\pm0.3$
Flux $_{20-200~\rm keV}$ [erg cm^-2 s^-1]	( $0.8\pm 0.4)\times 10^{-9}$	( $0.7\pm 0.4)\times 10^{-9}$	( $1.04\pm 0.08)\times 10^{-9}$
$\chi ^2$ (d.o.f.)	1.3 (52)	1.4 (52)
			Ref. (4)

^* Errors are computed introducing systematic errors in order to reduce the $\chi ^2$ below 2.0.
(1) Toor & Seward (1974); (2) Galloway (2000); (3) Dove et al. (1998); (4) D'Amico et al. (2001).