Monitoring of the polarized H2O maser emission around the massive protostars W75N(B)-VLA 1 and W75N(B)-VLA 2

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Table 3.

Comparison of 22 GHz H₂O maser parameters between epochs 2014.46, 2016.45, 2018.44, and 2020.82.

	VLA 1				VLA 2

	2014.46	2016.45	2018.44	2020.82	2014.46	2016.45	2018.44	2020.82
Number of maser features	28	20	20	10	43	37	44	39
V_lsr range (km s⁻¹)	[ + 7.9; +19.7]	[ + 2.7; +16.4]	[ + 7.8; +15.0]	[ + 8.8; +26.4]	[ − 11.6; +21.2]	[ − 15.6; +20.7]	[ − 15.9; +28.2]	[ − 1.0; +27.2]
I range (Jy beam⁻¹)	[0.43; 1205.52]	[0.24; 1619.87]	[2.08; 446.25]	[0.14; 302.47]	[0.21; 31.70]	[0.23; 90.99]	[0.04; 128.02]	[0.05; 285.16]
⟨Δv_L⟩ (km s⁻¹)	1.3	1.1	1.0	1.7	0.7	0.7	0.7	0.7

	Polarization

P_l range (%)	[0.4; 15.6]	[0.7; 2.2]	[0.7; 10.6]	[0.1; 0.3]	[0.9; 4.6]	[0.6; 2.7]	[1.0; 2.3]	[0.2; 1.9]
P_V range (%)	−	3.5	1.6	−	−	[4.9; 7.8]	[1.5; 2.9]	1.3

	Intrinsic characteristics

ΔV_i range (km s⁻¹)	[0.4; 4.2]	[3.8; 4.3]	[0.4; 3.9]	2.6	[1.6; 1.9]	[0.4; 4.2]	[0.8; 3.6]	[2.6; 3.8]
T_bΔΩ range (log K sr)	[7.0; 9.4]	[6.8; 9.3]	[8.9; 10.5]	10.6	[8.9; 9.2]	[6.1; 9.4]	[6.0; 10.5]	[8.2; 8.4]
⟨ΔV_i⟩ ^(a) (km s⁻¹)
⟨T_bΔΩ⟩ ^(a) (log K sr)
T^(b) (K)
Γ + Γ_ν^(c)	20	18	16	15	7	18	10	18

	Magnetic field

χ range (°)	[ − 62; +48]	[ − 76; −11]	[ − 88; +88]	[ − 67; −5]	[ − 47; −31]	[ − 77; +88]	[ − 89; +90]	[ − 54; +40]
θ range (°)	[ + 75; +90]	+90	[ + 62; +90]	[ + 5; +54]	[ + 79; +86]	[ + 76; +90]	[ + 14; +90]	[ + 66; +90]
Φ_B range (°)	[ − 42; +68]	[ + 14; +18]	[ − 4; +88]	[ − 5; −67]	[ + 43; +51]	[ − 3; +45]	[ − 25; +85]	[ − 64; +80]
\|B_\|\|\| range (mG)	−	676	[733; 764]	−	−	[1498; 2426]	[355; 439]	452
⟨χ⟩ ^(d) (°)	−47 ± 30	−60 ± 16	−87 ± 5	−32 ± 44	−40 ± 7	−74 ± 19	+76 ± 12	−73 ± 62
⟨θ⟩ ^(d) (°)
⟨Φ_B⟩ ^(d) (°)	+43 ± 30	+30 ± 16	−10 ± 36	−32 ± 44	+50 ± 7	+16 ± 19	−29 ± 36	+61 ± 31
⟨\|B_\|\|\|⟩ ^(e) (mG)	−	676 ± 102	748 ± 22	−	−	1755 ± 656	399 ± 59	452 ± 68
⟨\|B\|⟩ ^(e,^f) (mG)	−	> 2076 ^(g)	3598 ± 106	−	−	> 5679 ^(h)	> 663 ⁽ⁱ⁾	> 598 ^(j)
Arithmetic mean of \|B_\|\|\| (mG)	−	676	748	−	−	1962	397	452

Notes.

^(a)

The averaged values are determined by analyzing the total full probability distribution function.

^(b)

T ≈ 100 × (⟨ΔV_i⟩/0.5)² is the gas temperature of the region where the H₂O masers arise, with ΔV_i the intrinsic maser linewidth (see Nedoluha & Watson 1992), in case turbulence is not present.

^(c)

Here Γ is the decay rate and Γ_ν is the cross-relaxation rate (e.g., Nedoluha & Watson 1992). The values of T_bΔΩ have to be adjusted according to the gas temperature by adding +1.3 (Γ + Γ_ν = 20), +1.3 (Γ + Γ_ν = 18), +1.2 (Γ + Γ_ν = 16), +1.2 (Γ + Γ_ν = 15), +0.8 (Γ + Γ_ν = 7), +1.3 (Γ + Γ_ν = 18), +1.0 (Γ + Γ_ν = 10), and +1.3 (Γ + Γ_ν = 18) as described in Anderson & Watson (1993).

^(d)

Error-weighted values, where the weights are w_i = 1/e_i and e_i is the error of the ith measurements.

^(e)

Error-weighted values, where we assumed weights of , with e_i being the error of the ith measurement, to take into more consideration the less uncertain measures.

^(f)

|B|=⟨|B_|||⟩/cos⟨θ⟩ if θ ≠ ±90°.

^(g)

We report the lower limit estimated by considering θ = θ + ε⁻ = 71°, where ε⁻ is one of the associated errors to θ (i.e., ).

^(h)

We report the lower limit estimated by considering θ = 72°.

⁽ⁱ⁾

We report the lower limit estimated by considering θ = 53°.

^(j)

We report the lower limit estimated by considering θ = 41°.

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