Small Carbon Chains in Circumstellar Envelopes
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چکیده
Observations of carbon-rich circumstellar envelopes were made using the Phoenix spectrograph on the Gemini South telescope to determine the abundance of small carbon chain molecules. Vibration–rotation lines of the ν3 antisymmetric stretch of C3 near 2040 cm−1 (4.902 μm) have been used to determine the column density for four carbon-rich circumstellar envelopes: CRL 865, CRL 1922, CRL 2023 and IRC +10216. We additionally calculate the column density of C5 for IRC +10216, and provide an upper limit for five more objects. An upper limit estimate for the C7 column density is also provided for IRC+10216. A comparison of these column densities suggests a revision to current circumstellar chemical models may
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تاریخ انتشار 2017