Results 21 to 30 of about 4,382,200 (272)

Chemical Abundances of Main-sequence, Turnoff, Subgiant, and Red Giant Stars from APOGEE Spectra. II. Atomic Diffusion in M67 Stars [PDF]

Astrophysical Journal, 2019
Chemical abundances for 15 elements (C, N, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, and Ni) are presented for 83 stellar members of the 4 Gyr old solar-metallicity open cluster M67.
D. Souto, C. A. Prieto, C. A. Prieto, K. Cunha, M. Pinsonneault, V. Smith, R. Garcia-Dias, R. Garcia-Dias, J. Bovy, D. A. García-Hernández, D. A. García-Hernández, J. Holtzman, Julie A. Johnson, H. Jönsson, S. Majewski, M. Shetrone, J. Sobeck, O. Zamora, O. Zamora, K. Pan, C. Nitschelm   +20 more
semanticscholar   +1 more source

VLT/FLAMES high-resolution chemical abundances in Sculptor: a textbook dwarf spheroidal galaxy [PDF]

Astronomy & Astrophysics, 2018
We present detailed chemical abundances for 99 red-giant branch stars in the centre of the Sculptor dwarf spheroidal galaxy, which have been obtained from high-resolution VLT/FLAMES spectroscopy.
V. Hill, 'Asa Sk'ulad'ottir, E. Tolstoy, K. Venn, M. Shetrone, P. Jablonka, F. Primas, G. Battaglia, T. D. Boer, P. Franccois, A. Helmi, A. Kaufer, B. Letarte, E. Starkenburg, M. Spite   +14 more
semanticscholar   +1 more source

Chemical Abundances along the 1G Sequence of the Chromosome Maps: The Globular Cluster NGC 3201 [PDF]

Astrophysical Journal, 2019
The Hubble Space Telescope (HST) UV Legacy Survey of Galactic Globular Clusters (GCs) has investigated multiple stellar populations by means of the “chromosome map” (ChM) diagnostic tool that maximizes the separation between stars with different chemical
A. Marino, A. Milone, A. Sills, David Yong, A. Renzini, L. Bedin, G. Cordoni, F. D’Antona, H. Jerjen, A. Karakas, E. Lagioia, G. Piotto, M. Tailo   +12 more
semanticscholar   +1 more source

How Efficient is Rotational Mixing in Massive Stars ? [PDF]

, 2007
The VLT-Flames Survey for Massive Stars (Evans05,Evans06) provides recise measurements of rotational velocities and nitrogen surface abundances of massive stars in the Magellanic Clouds.
Anders, P., Brott, I., Hunter, I., Langer, N.   +3 more
core   +6 more sources

The Open Cluster Chemical Abundances and Mapping Survey. II. Precision Cluster Abundances for APOGEE Using SDSS DR14 [PDF]

Astronomical Journal, 2018
The Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to produce a comprehensive, uniform, infrared-based spectroscopic data set for hundreds of open clusters, and to constrain key Galactic dynamical and chemical parameters from this ...
J. Donor, P. Frinchaboy, K. Cunha, B. Thompson, J. O’Connell, G. Zasowski, K. Jackson, B. McGrath, B. McGrath, Andres Almeida, D. Bizyaev, D. Bizyaev, R. Carrera, D. A. García-Hernández, C. Nitschelm, K. Pan, O. Zamora   +16 more
semanticscholar   +1 more source

Chemical Abundances in a Turbulent Medium–H2, OH+, H2O+, ArH+ [PDF]

Astrophysical Journal, 2019
Supersonic turbulence results in strong density fluctuations in the interstellar medium (ISM), which have a profound effect on the chemical structure. Particularly useful probes of the diffuse ISM are the ArH+, OH+, H2O+ molecular ions, which are highly ...
S. Bialy, D. Neufeld, M. Wolfire, A. Sternberg, B. Burkhart   +4 more
semanticscholar   +1 more source

Chemical Evolution of the Galactic Bulge as Derived from High-Resolution Infrared Spectroscopy of K and M Red Giants [PDF]

, 2006
We present chemical abundances in K and M red-giant members of the Galactic bulge derived from high-resolution infrared spectra obtained with the Phoenix spectrograph on Gemini-South.
Bessel M. S., Costes M., Edvardsson B., Gratton R. G., Gustafsson B., Katia Cunha, Nissen P. E., Plez B., Udalski A., Udalski A., Verne V. Smith   +10 more
core   +3 more sources

Machine learning in APOGEE: Identification of stellar populations through chemical abundances [PDF]

Astronomy & Astrophysics, 2019
Context. The vast volume of data generated by modern astronomical surveys offers test beds for the application of machine-learning. In these exploratory applications, it is important to evaluate potential existing tools and determine those that are ...
R. Garcia-Dias, C. Prieto, J. Almeida, P. Palicio   +3 more
semanticscholar   +1 more source

Neon and Sulfur Abundances of Planetary Nebulae in the Magellanic Clouds [PDF]

, 2007
The chemical abundances of neon and sulfur for 25 planetary nebulae (PNe) in the Magellanic Clouds are presented. These abundances have been derived using mainly infrared data from the Spitzer Space Telescope.
Aller L. H., de Graauw T., Feldman U., Fluks M. A., Grevesse N., J. Bernard‐Salas, J. R. Houck, Monk D. J., P. W. Morris, Pena M., S. Gutenkunst, S. R. Pottasch, Zijlstra A. A.   +12 more
core   +4 more sources

Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program. II. Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Eu [PDF]

, 2017
To understand the formation and evolution of the different stellar populations within our Galaxy it is essential to combine detailed kinematical and chemical information for large samples of stars.
E. D. Mena, M. Tsantaki, V. Adibekyan, S. Sousa, N. Santos, J. Hern'andez, G. Israelian   +6 more
semanticscholar   +1 more source