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Full-Text Articles in Physical Sciences and Mathematics
Small Carbon Chains In Circumstellar Envelopes, R. J. Hargreaves, K. Hinkle, P. F. Bernath
Small Carbon Chains In Circumstellar Envelopes, R. J. Hargreaves, K. Hinkle, P. F. Bernath
Chemistry & Biochemistry Faculty Publications
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 …
Searching For Chemical Signatures Of Multiple Stellar Populations In The Old, Massive Open Cluster Ngc 6791, Angela Bragaglia, Christopher Sneden, Eugenio Carretta, Raffaele G. Gratton, Sara Lucatello, Peter F. Bernath, James S. A. Brooke, Ram S. Ram
Searching For Chemical Signatures Of Multiple Stellar Populations In The Old, Massive Open Cluster Ngc 6791, Angela Bragaglia, Christopher Sneden, Eugenio Carretta, Raffaele G. Gratton, Sara Lucatello, Peter F. Bernath, James S. A. Brooke, Ram S. Ram
Chemistry & Biochemistry Faculty Publications
Galactic open and globular clusters (OCs, GCs) appear to inhabit separate regions of the age-mass plane. However, the transition between them is not easily defined because there is some overlap between high-mass, old OCs and low-mass, young GCs. We are exploring the possibility of a clear-cut separation between OCs and GCs using an abundance feature that has been found so far only in GCs: (anti)correlations between light elements. Among the coupled abundance trends, the Na-O anticorrelation is the most widely studied. These anticorrelations are the signature of self-enrichment, i.e., of a formation mechanism that implies multiple generations of stars. Here …
Line Lists For The A2Π-X 2Σ+ (Red) And B2Σ+-X 2Σ+ (Violet) Systems Of Cn, 13c14n, And 12c15n, And Application To Astronomicalspectra, Christopher Sneden, Sara Lucatello, Ram S. Ram, James S. A. Brooke, Peter Bernath
Line Lists For The A2Π-X 2Σ+ (Red) And B2Σ+-X 2Σ+ (Violet) Systems Of Cn, 13c14n, And 12c15n, And Application To Astronomicalspectra, Christopher Sneden, Sara Lucatello, Ram S. Ram, James S. A. Brooke, Peter Bernath
Chemistry & Biochemistry Faculty Publications
New red and violet system line lists for the CN isotopologues 13C14N and 12C15N have been generated. These new transition data are combined with those previously derived for 12C14N, and applied to the determination of CNO abundances in the solar photosphere and in four red giant stars: Arcturus, the bright, very low-metallicity star HD 122563, and the carbon-enhanced metal-poor stars HD 196944 and HD 201626. When both red and violet system lines are detectable in a star, their derived N abundances are in good agreement. The mean N abundances determined in …