**Table 1:** NGC 7538 IRS1 outflow directions reported for various tracers.
Tracer	Structure	Beam size	Scale	PA of	Dynamical	Ref.	Comments
		[ $^{\prime\prime}$ ]	[ $^{\prime\prime}$ ]	outflow	age^f		(velocities in [km s^-1])
				direction [ $^\circ$ ]	[10³ yr]
Methanol masers		0.03^c		+19^a,d	-	[8]	see Fig. 3
1.0 cm cont.	inner core $\la$ $0\hbox{$.\!\!^{\prime\prime}$ }5$	0.13	0.4	+0^a	<0.03	[9]	$t_{\rm e}=0.15$ yr^e
1.3 cm cont.	inner core $\la$ $0\hbox{$.\!\!^{\prime\prime}$ }4$	0.11	0.4	+0^a	<0.02	[5]
6.0 cm cont.	inner core $\la$ $0\hbox{$.\!\!^{\prime\prime}$ }75$	0.35	0.4	+0	<0.04	[1]
1.0 cm cont.	outer core $\ga$ $0\hbox{$.\!\!^{\prime\prime}$ }5$	0.13	1.0	-25^a	>0.03	[9]	$t_{\rm e}=0.3$ yr^e
1.3 cm cont.	outer core $\ga$ $0\hbox{$.\!\!^{\prime\prime}$ }4$	0.11	1.0	-25^a	>0.02	[5]
6.0 cm cont.	outer core $\ga$ $0\hbox{$.\!\!^{\prime\prime}$ }75$	0.35	1.0	-15 ... -20	>0.04	[1]
6.0 cm cont.	outer core $\ga$ $0\hbox{$.\!\!^{\prime\prime}$ }5$	0.4	1.0	-25^a	>0.03	[9]
MIR $11.7~\mu$ m	IRS1 Elongation	0.43	3	-45	0.16	[10]	see Fig. 6k
MIR $18.3~\mu$ m	IRS1 Elongation	0.54	4	-45	0.16	[10]	see Fig. 6l
NIR K'-band	IRS1 Elongation	0.3	0.6	-78	0.03	-	see Fig. 3
NIR K'-band	feature A	0.3	1.6	-65	0.08	-	see Fig. 3
NIR K'-band	feature F	0.3	2.1	-33	0.11	-	see Fig. 3
NIR K'-band	feature B	0.3	3.0	-39	0.16	-	see Fig. 3
NIR K'-band	feature B'	0.3	3.3	-57	0.18	-	see Fig. 3
NIR K'-band	feature C	0.3	4.8	+6	0.25	-	see Fig. 3
NIR K'-band	feature E	0.3	6.2	-20	0.33	-	see Fig. 3
NIR K'-band	feature D	0.3	7.4	+10	0.39	-	see Fig. 3
NIR K'-band	eastern wall	0.3	-	+25	-	-	see Fig. 3
NIR K'-band	western wall	0.3	-	-65	-	-	see Fig. 3
[Fe II] 1.65 $\mu$ m		1	15^a	N-S^a	0.8	[7]	around IRS2; see Fig. 6i
H₂	northern bow		30^a	N-S	1.5	[6]
H₂		1	27^a	-25^a	1.4	[7]	shell-like structure; see Fig. 6i
H₂	southern bow		45^a	155^a	2.3	[6]	see Fig. 6h
IRAC bands	southern bow	1	40	145	2.2	-	see Fig. 6a...e
CO	low velocities	7	5^a,b	E-W	0.9	[3]	$-11<\tilde{V}_{\rm b}<-6$ ; $2<\tilde{V}_{\rm r}<9$ ; see Fig. 6g
CO	high velocities	7	15^b	-35	15	[3]	$-17<\tilde{V}_{\rm b}<-11$ ; $9<\tilde{V}_{\rm r}<15$ ; see Fig. 6g
CO		34	18^b	-50^a	15	[2]	$-24<\tilde{V}_{\rm b}<-8$ ; $9<\tilde{V}_{\rm r}<22$
CO		16	13^a,b	-40	14	[4]	$-14<\tilde{V}_{\rm b}<-9$ ; $11<\tilde{V}_{\rm r}<16$ ; see Fig. 6f
CO		45	12^a,b	-50^a	10	[3]	$-24<\tilde{V}_{\rm b}<-8$ ; $9<\tilde{V}_{\rm r}<22$

Note - $\tilde{V}_{\rm r}$ and $\tilde{V}_{\rm b}$ are measured relative to the velocity of methanol maser feature A ( $\tilde{V} = V - 56.25$ km s^-1). ^a Estimated from figures presented within the reference paper; therefore, with limited accuracy; ^b the half-separation between the red- and blue-shifted CO lobe is given; ^c for VLBI observations, we give the estimated error on the absolute position of the measured maser spots; ^d the expected outflow direction is given; i.e., perpendicular to the measured orientation of maser feature A; ^e electron recombination time given in the reference paper; ^f assuming an outflow velocity of 250 km s^-1, which was measured by Gaume et al. (1995) within the H66 $\alpha$ recombination line. For the CO emission, we also use the measured CO outflow velocity and provide the corresponding dynamical age in brackets. Since all velocities are measured along LOS, this timescale can only provide upper limits.
References: [1] Campbell (1984); [2] Fischer et al. (1985); [3] Scoville et al. (1986); [4] Kameya et al. (1989); [5] Gaume et al. (1995); [6] Davis et al. (1998); [7] Bloomer et al. (1998); [8] Minier et al. (2000); [9] Franco-Hernández & Rodríguez (2004); [10] De Buizer & Minier (2005).

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