On the accretion process in a high-mass star forming region - A multitransitional THz Herschel-HIFI study of ammonia toward G34.26+0.15

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Volume 585 (January 2016)

A&A, 585 (2016) A158

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Table 2

Observed ammonia transitions toward G34.3+0.15 with Herschel-HIFI.

	Transition	Frequency^a	E _l ^b	E _u ^c	A _ul ^d	n _crit ^e	g _l / g _u ^f	HPBW ^g	η _mb ^h	T _C ⁱ	1σ/T_C^j
	(J_K,ϵ)	(GHz)	(K)	(K)	log ₁₀(s^-1)	(cm^-3)		(″)		(K)	(%)

o-NH₃	1_0 +–0_0 +	572.498	0	27	−2.802	3.4e7	4/12	36	0.62	0.86	3.0
	2_0 +–1_0 +	1214.853	27	86	−1.742	3.1e8	12/20	17	0.61	4.35	2.4
	3_0 +–2_{0 +}	1763.524	86	170	−1.226	1.1e9	20/28	12	0.60	6.60	1.1

p-NH₃	2_1 −–1_1 −	1168.452	23	79	−1.918	3.1e8	6/10	18	0.61	4.50	1.5
	2_1 +–1_1 +	1215.246	22	80	−1.867	3.5e8	6/10	17	0.61	4.37	2.4
	3_1 +–2_1 +	1763.601	80	165	−1.277	1.2e9	10/14	12	0.60	6.60	1.1
	3_2 +–2_2 +	1763.823	64	149	−1.482	9.3e8	10/14	12	0.60	6.60	1.1

Notes. All spectroscopic data are taken from JPL. . .

^(a)

The highest error in frequency is 0.1 MHz for the 1764 GHz lines.

^(b)

Lower state energies.

^(c)

Upper state energies.

^(d)

The Einstein coefficient for spontaneous emission A_ul.

^(e)

Critical density, A_ul/C_ul, where C_ul is the collision coefficient evaluated for 50 K.

^(f)

Ratio of lower and upper state degeneracies.

^(g)

The Herschel half power beam width at respective frequency (Mueller et al. 2014)

^(h)

The main beam efficiency (Mueller et al. 2014).

⁽ⁱ⁾

The observed SSB continuum intensity not corrected for main beam efficiency.

^(j)

The rms noise relative to T_C

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