Detection of Vibrationally Excited CO in IRC+10216

Abstract

Using the Submillimeter Array we have detected the J=3-2 and 2-1 rotational transitions from within the first vibrationally excited state of CO toward the extreme carbon star IRC+10216 (CW Leo). The emission remains spatially unresolved with an angular resolution of ~2" and, given that the lines originate from energy levels that are ~3100 K above the ground state, almost certainly originates from a much smaller (~10^{14} cm) sized region close to the stellar photosphere. Thermal excitation of the lines requires a gas density of ~10^{9} cm^{-3}, about an order of magnitude higher than the expected gas density based previous infrared observations and models of the inner dust shell of IRC+10216.

Accepted for publication in ApJ Letters

References in corpus (3)

• Detection of circumstellar CH2CHCN, CH2CN, CH3CCH and H2CS
• Submillimeter vibrationally excited water emission from the peculiar red supergiant VY CMa
• Radio continuum monitoring of the extreme carbon star IRC+10216

Cited by in corpus (7)

• A high resolution line survey of IRC+10216 with Herschel. First results: Detection of warm silicon dicarbide SiC2
• The growth of carbon chains in IRC+10216 mapped with ALMA
• Quantum dynamics of CO-H${}_2$ in full dimensionality
• An Interferometric Spectral-line Survey of IRC+10216 in the 345 GHz Band
• ALMA observations of the vibrationally-excited rotational CO transition $v=1,J=3-2$ towards five AGB stars
• Accurate laboratory rest frequencies of vibrationally excited CO up to $varv=3$ and up to 2 THz
• Vibrationally Excited C${}_4$H