Tentative detection of phosphine in IRC+10216

Abstract

The J,K = 1,0-0,0 rotational transition of phosphine (PH3) at 267 GHz has been tentatively identified with a T_MB = 40 mK spectral line observed with the IRAM 30-m telescope in the C-star envelope IRC+10216. A radiative transfer model has been used to fit the observed line profile. The derived PH3 abundance relative to H2 is 6 x 10^(-9), although it may have a large uncertainty due to the lack of knowledge about the spatial distribution of this species. If our identification is correct, it implies that PH3 has a similar abundance to that reported for HCP in this source, and that these two molecules (HCP and PH3) together take up about 5 % of phosphorus in IRC+10216. The abundance of PH3, as that of other hydrides in this source, is not well explained by conventional gas phase LTE and non-LTE chemical models, and may imply formation on grain surfaces.

4 pages, 2 figures; accepted for publication in A&A Letters

References in corpus (2)

• Oxygen Chemistry in the Circumstellar Envelope of the Carbon-Rich Star IRC+10216
• A Detailed Analysis of the Dust Formation Zone of IRC+10216 Derived from Mid-IR Bands of C2H2 and HCN

Cited by in corpus (6)

• New molecules in IRC+10216: confirmation of C${}_5$S and tentative identification of MgCCH, NCCP, and SiH${}_3$CN
• Confirmation of circumstellar phosphine
• Chemical equilibrium in AGB atmospheres: Successes, failures, and prospects for small molecules, clusters, and condensates
• ExoMol molecular line lists - XXIII: spectra of PO and PS
• Chemical complexity of phosphorous bearing species in various regions of the Interstellar medium
• A spectral line survey of IRC +10216 between 13.3 and 18.5 GHz