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Bailleux S.,CNRS Atomic and Molecular Physics Laboratory | Martin-Drumel M.A.,Synchrotron Soleil | Martin-Drumel M.A.,CNRS Orsay Institute for Molecular Science | Margules L.,CNRS Atomic and Molecular Physics Laboratory | And 8 more authors.
Astronomy and Astrophysics | Year: 2012

Context. High-resolution rotational spectroscopy of the imidogen radical has been limited to the 14NH and 14ND isotopologues. Imidogen is an important intermediate in the astronomical synthesis of ammonia. Recently, the 14N/ 15N isotopic ratio in ammonia has been obtained in cold, dense molecular clouds. Aims. We conducted a laboratory search for rotational transitions of 15NH to investigate in more detail the 14N/ 15N ratio in the interstellar medium. Methods. 15NH was generated in a positive column discharge in a flowing 15NH 3-He (SOLEIL synchrotron) or 15NH 3-Ar (PhLAM) mixture. High-resolution spectroscopic study of the 15NH isotopologue of imidogen in its ground electronic and vibrational state X̃ 3Σ -) was carried out in the THz range (up to 225 cm -1) with the AILES beamline of the SOLEIL synchrotron and subsequently with the PhLAM spectrometer (around 942 GHz). The observed fine and hyperfine structures were analysed, yielding an accurate set of rotational, fine, and hyperfine parameters. Results. The reported frequencies and molecular constants are suitable for radioastronomical searches of this key species and for 14N/ 15N isotopic ratio astronomical determination. © 2012 ESO. Source

Carter B.,Laboratoire Of Lunivers Et Of Ses Theories
General Relativity and Gravitation | Year: 2010

This is a reprinting of Part 2 of Brandon Carter's lectures given at the 1972 Les Houches school on black holes, first published in a book of proceedings of that school in 1973, in which the author presents a general theory of stationary black holes. The paper has been selected by the Editors of General Relativity and Gravitation for re-publication in the Golden Oldies series of the journal. Several errors of the original text were corrected for this reprinting by the author. The reprinted article is accompanied by an editorial note written by Marek Abramowicz. © 2010 Springer Science+Business Media, LLC. Source

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