Search

Your search keyword '"Smith, V V"' showing total 25 results
Start Over Author "Smith, V V" Journal the astrophysical journal
25 results on '"Smith, V V"'

1. A Perspective on the Milky Way Bulge Bar as Seen from the Neutron-capture Elements Cerium and Neodymium with APOGEE

Author

Sales-Silva, J. V., primary, Cunha, K., additional, Smith, V. V., additional, Daflon, S., additional, Souto, D., additional, Guerço, R., additional, Queiroz, A., additional, Chiappini, C., additional, Hayes, C. R., additional, Masseron, T., additional, Hasselquist, Sten, additional, Horta, D., additional, Prantzos, N., additional, Zoccali, M., additional, Allende Prieto, C., additional, Barbuy, B., additional, Beaton, R., additional, Bizyaev, D., additional, Fernández-Trincado, J. G., additional, Frinchaboy, P. M., additional, Holtzman, J. A., additional, Johnson, J. A., additional, Jönsson, Henrik, additional, Majewski, S. R., additional, Minniti, D., additional, Nidever, D. L., additional, Schiavon, R. P., additional, Schultheis, M., additional, Sobeck, J., additional, Stringfellow, G. S., additional, and Zasowski, G., additional

Published
2024
Full Text
View/download PDF

2. Exploring the S-process History in the Galactic Disk: Cerium Abundances and Gradients in Open Clusters from the OCCAM/APOGEE Sample

Author

Sales-Silva, J. V., primary, Daflon, S., additional, Cunha, K., additional, Souto, D., additional, Smith, V. V., additional, Chiappini, C., additional, Donor, J., additional, Frinchaboy, P. M., additional, García-Hernández, D. A., additional, Hayes, C., additional, Majewski, S. R., additional, Masseron, T., additional, Schiavon, R. P., additional, Weinberg, D. H., additional, Beaton, R. L., additional, Fernández-Trincado, J. G., additional, Jönsson, H., additional, Lane, R. R., additional, Minniti, D., additional, Manchado, A., additional, Moni Bidin, C., additional, Nitschelm, C., additional, O’Connell, J., additional, and Villanova, S., additional

Published
2022
Full Text
View/download PDF

3. The metallicity of M4: Accurate spectroscopic fundamental parameters for four giants

Author

Drake, J. J, Smith, V. V, and Suntzeff, N. B

Subjects
Astrophysics
Abstract

High-quality spectra, covering the wavelength range 5480 to 7080 A, have been obtained for four giant stars in the intermediate-metallicity CN-bimodal globular cluster M4 (NGC 6121). We have employed a model atmosphere analysis that is entirely independent from cluster parameters, such as distance, age, and reddening, in order to derive accurate values for the stellar parameters effective temperature, surface gravity, and microturbulence, and for the abundance of iron relative to the Sun, (Fe/H), and of calcium, Ca/H, for each of the four stars. Detailed radiative transfer and statistical equilibrium calculations carried out for iron and calcium suggest that departures from local thermodynamic equilibrium are not significant for the purposes of our analysis. The spectroscopically derived effective temperatures for our program stars are hotter by about 200 K than existing photometric calibrations suggest. We conclude that this is due partly to the uncertain reddening of M4 and to the existing photometric temperature calibration for red giants being too cool by about 100 K. Comparison of our spectroscopic and existing photometric temperatures supports the prognosis of a significant east-west gradient in the reddening across M4. Our derived iron abundances are slightly higher than previous high-resolution studies suggested; the differences are most probably due to the different temperature scale and choice of microturbulent velocities adopted by earlier workers. The resulting value for the metallicity of M4 is (Fe/H )(sub M4) = -1.05 + or - 0.15. Based on this result, we suggest that metallicities derived in previous high-dispersion globular cluster abundance analyses could be too low by 0.2 to 0.3 dex. Our calcium abundances suggest an enhancement of calcium, an alpha element, over iron, relative to the Sun, in M4 of (Ca/H) = 0.23.

Published
1994
Full Text
View/download PDF

4. Chemical Abundances of M-Dwarfs from the Apogee Survey. I. The Exoplanet Hosting Stars Kepler-138 and Kepler-186

Author

Souto, D., primary, Cunha, K., additional, García-Hernández, D. A., additional, Zamora, O., additional, Prieto, C. Allende, additional, Smith, V. V., additional, Mahadevan, S., additional, Blake, C., additional, Johnson, J. A., additional, Jönsson, H., additional, Pinsonneault, M., additional, Holtzman, J., additional, Majewski, S. R., additional, Shetrone, M., additional, Teske, J., additional, Nidever, D., additional, Schiavon, R., additional, Sobeck, J., additional, Pérez, A. E. García, additional, Chew, Y. Gómez Maqueo, additional, and Stassun, K., additional

Published
2017
Full Text
View/download PDF

9. FLUORINE ABUNDANCES IN GALACTIC ASYMPTOTIC GIANT BRANCH STARS

Author

Abia, C., primary, Cunha, K., additional, Cristallo, S., additional, de Laverny, P., additional, Domínguez, I., additional, Eriksson, K., additional, Gialanella, L., additional, Hinkle, K., additional, Imbriani, G., additional, Recio-Blanco, A., additional, Smith, V. V., additional, Straniero, O., additional, and Wahlin, R., additional

Published
2010
Full Text
View/download PDF

12. Exploring Halo Substructure with Giant Stars. III. First Results from the Grid Giant Star Survey and Discovery of a Possible Nearby Sagittarius Tidal Structure in Virgo

Author

Kundu, A., primary, Majewski, S. R., additional, Rhee, J., additional, Rocha-Pinto, H. J., additional, Polak, A. A., additional, Slesnick, C. L., additional, Kunkel, W. E., additional, Johnston, K. V., additional, Patterson, R. J., additional, Geisler, D., additional, Gieren, W., additional, Seguel, J., additional, Smith, V. V., additional, Palma, C., additional, Arenas, J., additional, Crane, J. D., additional, and Hummels, C. B., additional

Published
2002
Full Text
View/download PDF

14. Observations of H \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $^{+}_{3}$ \end{document} in the Diffuse Interstellar Medium

Author

McCall, B. J., primary, Hinkle, K. H., additional, Geballe, T. R., additional, Moriarty‐Schieven, G. H., additional, Evans II, N. J., additional, Kawaguchi, K., additional, Takano, S., additional, Smith, V. V., additional, and Oka, T., additional

Published
2002
Full Text
View/download PDF

17. Early Observations of SN 1993J in M81 at McDonald Observatory

Author

Wheeler, J. C., primary, Barker, E., additional, Benjamin, R., additional, Boisseau, J., additional, Clocchiatti, A., additional, de Vaucouleurs, G., additional, Gaffney, N., additional, Harkness, R. P., additional, Khokhlov, A. M., additional, Lester, D. F., additional, Smith, B. J., additional, Smith, V. V., additional, and Tomkin, J., additional

Published
1993
Full Text
View/download PDF

25. FLUORINE ABUNDANCES IN GALACTIC ASYMPTOTIC GIANT BRANCH STARS

Author

P. de Laverny, Gianluca Imbriani, Kjell Eriksson, I. Dominguez, Alejandra Recio-Blanco, Rurik Wahlin, Oscar Straniero, Katia Cunha, Sergio Cristallo, Lucio Gialanella, Verne V. Smith, K. H. Hinkle, Carlos Abia, Abia, C., Cunha, K., Cristallo, S., de Laverny, P., Domínguez, I., Eriksson, K., Gialanella, L., Hinkle, K., Imbriani, Gianluca, Recio Blanco, A., Smith, V. V., Stranier, O., and Wahlin, R.

Subjects
Physics, abundance, K-type main-sequence star, Astronomy, chemistry.chemical_element, Astronomy and Astrophysics, stars: AGB and post-AGB, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, nuclear reaction, stars: abundance, Carbon star, stars: carbon, Stars, chemistry, nucleosynthesi, Space and Planetary Science, Abundance (ecology), Nucleosynthesis, Astrophysics::Solar and Stellar Astrophysics, Asymptotic giant branch, Astrophysics::Earth and Planetary Astrophysics, Carbon, Astrophysics::Galaxy Astrophysics, Main sequence
Abstract

An analysis of the fluorine abundance in Galactic asymptotic giant branch (AGB) carbon stars (24 N-type, 5 SC-type, and 5 J-type) is presented. This study uses the state-of-the-art carbon-rich atmosphere models and improved atomic and molecular line lists in the 2.3 μm region. Significantly lower F abundances are obtained in comparison to previous studies in the literature. This difference is mainly due to molecular blends. In the case of carbon stars of SC-type, differences in the model atmospheres are also relevant. The new F enhancements are now in agreement with the most recent theoretical nucleosynthesis models in low-mass AGB stars, solving the long-standing problem of F in Galactic AGB stars. Nevertheless, some SC-type carbon stars still show larger F abundances than predicted by stellar models. The possibility that these stars are of larger mass is briefly discussed.

Published
2010

Catalog

Books, media, physical & digital resources
See catalog results