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 present the first detection of the l-C3H+ hydrocarbon in the interstellarmedium. The Horsehead WHISPER project, a millimeter unbiased line survey at twopositions, namely the photo-dissociation region (PDR) and the nearby shieldedcore, revealed a consistent set of eight unidentified lines toward the PDRposition. Six of them are detected with a signal-to-noise ratio from 6 to 19,while the two last ones are tentatively detected. Mostly noise appears at thesame frequency toward the dense core, located less than 40" away. Wesimultaneously fit 1) the rotational and centrifugal distortion constants of alinear rotor, and 2) the Gaussian line shapes located at the eight predictedfrequencies. The observed lines can be accurately fitted with a linear rotormodel, implying a 1Sigma ground electronic state. The deduced rotationalconstant value is Be= 11244.9512 +/- 0.0015 MHz, close to that of l-C3H. Wethus associate the lines to the l-C3H+ hydrocarbon cation, which enables us toconstrain the chemistry of small hydrocarbons. A rotational diagram is thenused to infer the excitation temperature and the column density. We finallycompare the abundance to the results of the Meudon PDR photochemical model.

The IRAM-30m line survey of the Horsehead PDR: II. First detection of the l-C3H+ hydrocarbon cation