NH₃ was observed first in its lowest J = K = 1 tunneling transition toward Sagittarius B2 (Sgr B2):
A. C. Cheung, D. M. Rank, C. H. Townes, D. D. Thornton, and W. J. Welch,
Detection of NH₃ Molecules in the Interstellar Medium by Their Microwave Emission
Phys. Rev. Lett. 21, 1701–1705 (1968).

The first detection of a rotation-inversion transition of NH₃ was also reported: J. Keene, G. A. Blake, and T. G. Philips,
First Detection of the Ground-State //J_K// = 1₀ – 0₀ Submillimeter Transition of Interstellar Ammonia
Astrophys. J. 271, L27–L30 (1983).

T. L. Wilson, K. Ruf, C. M. Walmsley, R. N. Martin, T. A. Pauls, and W. Batria
reported on the
Detection of the (8,8) and (9,9) Absorption Lines of Ammonia: the Hot Molecular Cloud toward Sgr B2
Astron. Astrophys. 115, 185−189 (1982).
Observations were made with the MPIfR 100 m Effelsberg telescope pointing toward Sgr B2(S).

T. L. Wilson, C. Henkel, and S. Hüttemeister, G. Dahmen, A. Linhart, C. Lemme, and J. Schmidt-Burgk
reported on
Hot Ammonia Emission: Kinetic Temperature Gradients in Orion-KL
Astron. Astrophys. 276, L29−L32 (1993).
The MPIfR 100 m Effelsberg telescope was employed for observations of ammonia inversion transitions with 10 ≤ J = K ≤ 14.

T. L. Wilson, C. Henkel, and S. Hüttemeister
announced
The detection of the (J, K) = (18, 18) line of NH3
Astron. Astrophys. 460, 533–538 (2006).
Observations with the Effelsberg 100 m dish were successful toward Sgr B2(M) and Sgr B2(N); only an upper limit was reported for Orion KL.

The detection of vibrationally excited NH₃ (v₂ = 1) was reported in:
R. Mauersberger, C. Henkel, and T. L. Wilson,
Vibrationally Excited Ammonia toward Orion-KL
Astron. Astrophys. 205, 235–242 (1988).
The IRAM 30 m dish was used for observations near 140.1 GHz.

—

NH₂D was detected initially toward Sgr B2 and Orion KL:
B. E. Turner, B. Zuckerman, M. Morris, and P.Palmer,
Microwave Detection of Interstellar Deuterated Ammonia
Astrophys. J. 219, L43–L47 (1978).
E. N. Rodriguez Kuiper, B. Zuckerman, and T. B. H. Kuiper,
Deuterated Ammonia Toward the Orion Nebula
Astrophys. J. 219, L49–L53 (1978).

¹⁵NH₃ was observed toward the Orion Molecular Cloud (OMC-1) soon thereafter:
T. L. Wilson and T. Pauls,
The Detection of Interstellar ¹⁵NH₃
Astron. Astrophys. 73, L10–L12 (1979).

NHD₂ was detected first toward the L134N dark cloud which is also known as L183:
E. Roueff, S. Tiné, L. H. Coudert, G. Pineau des Forêts, E. Falgarone, and M. Gerin,
Detection of Doubly Deuterated Ammonia in L134N
Astron. Astrophys. 354, L63–L66 (2000).

Finally, even ND₃ was detected in NGC 1333 and in the Barnard 1 Cloud:
F. F. S. van der Tak, P. Schilke, H. S. P. Müller, D. C. Lis, T. G. Phillips, M. Gerin, and E. Roueff,
Triply Deuterated Ammonia in NGC 1333
Astron. Astrophys. 388, L53–L56 (2002).
D. C. Lis, E. Roueff, M. Gerin, T. G. Phillips, L. H. Coudert, F. F. S. van der Tak, and P. Schilke,
Detection of Triply Deuterated Ammonia in the Barnard 1 Cloud
Astrophys. J. 571, L55–L58 (2002).

The observation of 1₁₁ (0⁺) – 1₀₁ (0^–) ortho transition of ¹⁵NH₂D with the IRAM 30m telescope toward Barnard-1b, NGC1333-DCO⁺, and L1689N was reported by:
M. Gerin, N. Marcelino, N. Biver, E. Roueff, L. H. Coudert, M. Elkeurti, D. C. Lis, and D. Bockelée-Morvan,
Detection of ¹⁵NH₂D in dense cores: a new tool for measuring the ¹⁴N/¹⁵N ratio in the cold ISM
Astron. Astrophys. 498, L9–L12 (2009).

---

Contributor(s): H. S. P. Müller; 12, 2004; 06, 2006 & 01, 2010

---