EDP Sciences
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Volume 427, Number 3, December I 2004
Page(s) 887 - 893
Section Interstellar and circumstellar matter
DOI http://dx.doi.org/10.1051/0004-6361:20041464

A&A 427, 887-893 (2004)
DOI: 10.1051/0004-6361:20041464

Multiply-deuterated species in prestellar cores

D. R. Flower1, G. Pineau des Forêts2, 3 and C. M. Walmsley4

1  Physics Department, The University, Durham DH1 3LE, UK
2  IAS, Université de Paris-Sud, 92405 Orsay Cedex, France
3  LUTH, Observatoire de Paris, 92195 Meudon Cedex, France
4  INAF, Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy

(Received 14 June 2004 / Accepted 5 August 2004)

We have studied the ortho, para, and, in the case of D 3+, meta forms of the multiply-deuterated isotopes of H 3+, under physical conditions believed to be appropriate to pre-protostellar cores. As deuterons have integral nuclear spin, I = 1, Bose-Einstein statistical laws apply. Having extended the network of chemical reactions used in our previous study (Walmsley et al. 2004), we have calculated the population densities of ortho- and para-D 2H + and of ortho- and meta-D 3+. In the former case, comparison is made with the recent observations of para-D 2H + in the prestellar core 16293E (Vastel et al. 2004). Using radiative transition probabilities computed by Ramanlal & Tennyson (2004), we have predicted the intensities of the near infrared vibrational transitions of the deuterated isotopes of H 3+. Many of these transitions can be observed, in absorption, only from above the Earth's atmosphere, but some might be detectable through atmospheric windows.

Key words: stars: formation -- astrochemistry -- ISM: clouds

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