English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We have observed the rotational ground-state (J = 1-0) transitions of DCO+,HN13C and DNC with the IRAM 30m telescope toward the dark cloud LDN 1512 whichhas exceptionally narrow lines permitting hyperfine splitting to be resolved inpart. The measured splittings of 50-300 kHz are used to derive nuclearquadrupole and spin-rotation parameters for these species. The measurements aresupplemented by high-level quantum-chemical calculations using coupled-clustertechniques and large atomic-orbital basis sets.  We find eQq = +151.12 (400) kHz and C_I = -1.12 (43) kHz for DCO+, eQq =272.5 (51) kHz for HN13C, and eQq(D) = 265.9 (83) kHz and eQq(N) = 288.2 (71)kHz for DNC. The numbers for DNC are consistent with previous laboratory data,while our constants for DCO+ are somewhat smaller than previous results basedon astronomical data. For both DCO+ and DNC, our results are more accurate thanprevious determinations. Our results are in good agreement with thecorresponding best theoretical estimates. We also derive updated rotationalconstants for HN13C: B = 43545.6000 (47) MHz and D = 93.7 (20) kHz.  The hyperfine splittings of the DCO+, DNC and HN13C J = 1-0 lines range over0.47-1.28 km/s, which is comparable to typical line widths in pre-stellar coresand to systematic gas motions on ~1000 AU scales in protostellar cores. Wepresent tabular information to allow inclusion of the hyperfine splitting inastronomical data interpretation. The large differences in the 14N quadrupoleparameters of DNC and HN13C have been traced to differences in the vibrationalcorrections caused by significant non-rigidity of these molecules, particularlyalong the bending coordinate.

Hyperfine structure in the J = 1-0 transitions of DCO+, DNC, and HN13C: astronomical observations and quantum-chemical calculations