Table 4: Spectral slopes derived from power-law fitting in the range 1-7 mm using literature values (Table 5) and our 7-mm data (Col. 2). For objects without centimetre measurements, a 20% contribution of free-free emission was assumed (denoted by brackets in Col. 3). Spectral slopes corrected for free-free radiation are listed in Col. 4. The estimated dust opacity indices $\beta ^{\sim }$ (Col. 5) were corrected for optically depth (using $\Delta =0.2$ ), yielding the final $\beta$ values (Col. 6).
Source mm slope f-f contribution f-f corrected $\beta$ estimate Opacity index

$\alpha_{\rm mm}$ at 7 mm (%) $\alpha_{\rm corr}$ $\beta^{\sim}\!=\!\alpha_{\rm corr}\!-\!2$ $\beta=(1+\Delta)\beta^{\sim}$

RY Tau 2.51 $\pm$ 0.10 24 2.66 $\pm$ 0.09 0.66 $\pm$ 0.09 0.8 $\pm$ 0.1

FT Tau 2.62 $\pm$ 0.17 (20) 2.76 $\pm$ 0.24 0.76 $\pm$ 0.24 0.9 $\pm$ 0.3

DG Tau B 2.88 $\pm$ 0.20 24 3.17 $\pm$ 0.19 1.17 $\pm$ 0.19 1.4 $\pm$ 0.2

DG Tau 2.45 $\pm$ 0.09 20 2.54 $\pm$ 0.11 0.54 $\pm$ 0.11 0.7 $\pm$ 0.1

HL Tau 2.93 $\pm$ 0.10 23 3.04 $\pm$ 0.12 1.04 $\pm$ 0.12 1.3 $\pm$ 0.1

UZ Tau E 2.56 $\pm$ 0.08 (20) 2.66 $\pm$ 0.09 0.66 $\pm$ 0.09 0.8 $\pm$ 0.1

DL Tau 2.73 $\pm$ 0.11 (20) 2.82 $\pm$ 0.14 0.82 $\pm$ 0.14 1.0 $\pm$ 0.2

CI Tau 3.00 $\pm$ 0.27 (20) 3.12 $\pm$ 0.30 1.12 $\pm$ 0.30 1.3 $\pm$ 0.4

DO Tau 2.29 $\pm$ 0.06 (20) 2.38 $\pm$ 0.07 0.38 $\pm$ 0.07 0.5 $\pm$ 0.1

GM Aur 3.17 $\pm$ 0.20 (20) 3.29 $\pm$ 0.20 1.29 $\pm$ 0.20 1.6 $\pm$ 0.2

**Table 4:** Spectral slopes derived from power-law fitting in the range 1-7 mm using literature values (Table 5) and our 7-mm data (Col. 2). For objects without centimetre measurements, a 20% contribution of free-free emission was assumed (denoted by brackets in Col. 3). Spectral slopes corrected for free-free radiation are listed in Col. 4. The estimated dust opacity indices $\beta ^{\sim }$ (Col. 5) were corrected for optically depth (using $\Delta =0.2$ ), yielding the final $\beta$ values (Col. 6).
Source	mm slope	f-f contribution	f-f corrected	$\beta$ estimate	Opacity index
	$\alpha_{\rm mm}$	at 7 mm (%)	$\alpha_{\rm corr}$	$\beta^{\sim}\!=\!\alpha_{\rm corr}\!-\!2$	$\beta=(1+\Delta)\beta^{\sim}$
RY Tau	2.51 $\pm$ 0.10	24	2.66 $\pm$ 0.09	0.66 $\pm$ 0.09	0.8 $\pm$ 0.1
FT Tau	2.62 $\pm$ 0.17	(20)	2.76 $\pm$ 0.24	0.76 $\pm$ 0.24	0.9 $\pm$ 0.3
DG Tau B	2.88 $\pm$ 0.20	24	3.17 $\pm$ 0.19	1.17 $\pm$ 0.19	1.4 $\pm$ 0.2
DG Tau	2.45 $\pm$ 0.09	20	2.54 $\pm$ 0.11	0.54 $\pm$ 0.11	0.7 $\pm$ 0.1
HL Tau	2.93 $\pm$ 0.10	23	3.04 $\pm$ 0.12	1.04 $\pm$ 0.12	1.3 $\pm$ 0.1
UZ Tau E	2.56 $\pm$ 0.08	(20)	2.66 $\pm$ 0.09	0.66 $\pm$ 0.09	0.8 $\pm$ 0.1
DL Tau	2.73 $\pm$ 0.11	(20)	2.82 $\pm$ 0.14	0.82 $\pm$ 0.14	1.0 $\pm$ 0.2
CI Tau	3.00 $\pm$ 0.27	(20)	3.12 $\pm$ 0.30	1.12 $\pm$ 0.30	1.3 $\pm$ 0.4
DO Tau	2.29 $\pm$ 0.06	(20)	2.38 $\pm$ 0.07	0.38 $\pm$ 0.07	0.5 $\pm$ 0.1
GM Aur	3.17 $\pm$ 0.20	(20)	3.29 $\pm$ 0.20	1.29 $\pm$ 0.20	1.6 $\pm$ 0.2

Source LaTeX | All tables | In the text