Results 31 to 40 of about 226,393 (319)

Chemical Abundances and Hierarchical Clustering [PDF]

Symposium - International Astronomical Union, 2004
In this contribution we study the chemical enrichment of the interstellar medium and stellar population of the building blocks of current typical galaxies in the field, in cosmological hydrodynamics simulations. The simulations include detailed modeling of chemical enrichment by SNIa and SNII In our simulations the missing metal problem is caused by ...
P. B. Tissera, D.G. Lambas
openaire   +1 more source

On the Galactic chemical evolution of sulphur. Sulphur abundances from the [S i] 1082 nm line in giants [PDF]

, 2013
Context. The Galactic chemical evolution of sulphur is still under debate. At low metallicities some studies find no correlation between [S/Fe] and [Fe/H], others find [S/Fe] increasing towards lower metallicities, and still others find a combination of ...
Dupree, A. K., Matrozis, E., Ryde, N.
core   +1 more source

Evidence for Ubiquitous Carbon Grain Destruction in Hot Protostellar Envelopes

The Astrophysical Journal Letters, 2023
Earth is deficient in carbon and nitrogen by up to ∼4 orders of magnitude compared with the Sun. Destruction of (carbon- and nitrogen-rich) refractory organics in the high-temperature planet-forming regions could explain this deficiency.
Pooneh Nazari, Benoît Tabone, Merel L. R. van ’t Hoff, Jes K. Jørgensen, Ewine F. van Dishoeck   +4 more
doaj   +1 more source

Chemical Abundances of the S star GZ Peg [PDF]

, 2009
The chemical compositions of stars from the Asymptotic Giant Branch are still poorly known due to the low temperatures of their atmospheres and therefore the presence of many molecular transitions hampering the analysis of atomic lines.
Allen, Alonso, Goriely, Gustafsson, Jorissen, L. Pompéia, Lebzelter, Smiljanic, Woolf   +8 more
core   +1 more source

Chemical Abundances in Field Red Giants from High-Resolution H-Band Spectra using the APOGEE Spectral Linelist

, 2012
High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory (KPNO) Fourier Transform Spectrometer (FTS), are analyzed to determine chemical abundances of 16 elements.
Bizyaev, Dmitry, Cunha, Katia, Holtzman, Jon, Johnson, Jennifer A., Majewski, Steven R., Meszaros, Szabolcs, Perez, Ana Garcia, Prieto, Carlos Allende, Schiavon, Ricardo, Shetrone, Matthew D., Smith, Verne V.   +10 more
core   +1 more source

Non-LTE abundances of Mg and K in extremely metal-poor stars and the evolution of [O/Mg], [Na/Mg], [Al/Mg] and [K/Mg] in the Milky Way [PDF]

, 2010
LTE abundances of light elements in extremely metal-poor (EMP) stars have been previously derived from high quality spectra. New derivations, free from the NLTE effects, will better constrain the models of the Galactic chemical evolution and the yields ...
Andrievsky, S. M., Bonifacio, P., Cayrel, R., François, P., Hill, V., Korotin, S. A., Spite, F., Spite, Monique   +7 more
core   +5 more sources

Chemical abundances of LINER galaxies – nitrogen abundance estimations

Monthly Notices of the Royal Astronomical Society
ABSTRACT In this work, we investigated the nitrogen and oxygen abundances in a sample of galaxies with Low Ionization Nuclear Emission Regions (LINERs) in their nucleus. Optical spectroscopic data (3600 – 10 000 Å) of 40 LINERs from the Mapping Nearby Galaxies (MaNGAs) survey were considered.
C B Oliveira, Â. C. Krabbe, O. L. Dors, I. A. Zinchenko, J. A. Hernández-Jiménez, M. V. Cardaci, G. F. Hägele, Gabriele S Ilha   +7 more
openaire   +3 more sources

A Systematic NLTE Study of Very Metal-poor Stars with Metallicity down to −4.3 dex. I. Global Stellar Parameters Based on High-resolution Spectra

The Astrophysical Journal
Very metal-poor (VMP) stars provide a record of the chemical composition and dynamics of the early Galaxy. Based on the high-resolution and high signal-to-noise ratio spectra from the Subaru Telescope for 103 VMP stars, in this series of papers we ...
Jianrong Shi, Gang Zhao, Shuai Liu, Zeming Zhou, Haining Li, Hongliang Yan, Sofya Alexeeva, Huawei Zhang, Wako Aoki, Tadafumi Matsuno, Jingkun Zhao, Huiling Chen, Yufu Shen   +12 more
doaj   +1 more source

Evolution of chemical abundances in Seyfert galaxies

, 2007
We computed the chemical evolution of spiral bulges hosting Seyfert nuclei, based on updated chemical and spectro-photometrical evolution models for the bulge of our Galaxy, made predictions about other quantities measured in Seyferts, and modeled the ...
Adams, Angeletti, Arimoto, Balcells, Baldwin, Ballero, Ballero, Ballero, Barth, Bentz, Bertin, Blain, Bondi, Brandt, Calura, Calura, Calura, Calura, Chiappini, Chiappini, Cimatti, Cioffi, Ciotti, Ciotti, Ciotti, Collin, Cox, Cox, D'Odorico, Di Matteo, Dietrich, Dietrich, Dunlop, Dwek, F. Calura, F. Matteucci, Fabian, Ferrarese, Ferrarese, Fields, Fields, Ford, François, Fraquelli, Freudling, Friaça, Fulbright, Fulbright, Galaz, Gebhardt, Gebhardt, Genzel, González Delgado, Granato, Groenewegen, Gu, Haiman, Hamann, Hamann, Hamann, Hernquist, Ho, Ho, Häring, Itoh, Iwamuro, Iwamuro, Jiang, Jimenez, Jimenez, Kaspi, Komossa, Kormendy, Kurucz, L. Ciotti, Laor, Launhardt, Lecureur, Lee, MacKenty, Magorrian, Maiolino, Maiolino, Marconi, Markowitz, Mathur, Matteucci, Matteucci, Matteucci, Matteucci, Matteucci, Matteucci, McLure, Monaco, Nagao, Nagao, Narayan, Nelson, Nomoto, Onken, Origlia, Origlia, Origlia, Ostriker, P. Padovani, Padovani, Peletier, Peletier, Petitjean, Pipino, Rich, Rodríguez-Ardila, Romano, S. K. Ballero, Salpeter, Sazonov, Scannapieco, Schmitt, Shields, Storchi-Bergmann, Storchi-Bergmann, Storchi-Bergmann, Storchi-Bergmann, Thomas, Thomas, Thompson, Tinsley, Tremaine, Turner, Ulrich, Van Loon, Verner, Wandel, Wandel, Wang, Warner, Wills, Wu, Yee, Yu, Zoccali, Zoccali   +141 more
core   +2 more sources

Mapping the evolution of mitochondrial complex I through structural variation

FEBS Letters, EarlyView.
Respiratory complex I (CI) is crucial for bioenergetic metabolism in many prokaryotes and eukaryotes. It is composed of a conserved set of core subunits and additional accessory subunits that vary depending on the organism. Here, we categorize CI subunits from available structures to map the evolution of CI across eukaryotes. Respiratory complex I (CI)
Dong‐Woo Shin, Tingting Chen, James A. Letts   +2 more
wiley   +1 more source