Results 31 to 40 of about 464,371 (256)

Oxygen abundances in unevolved metal-poor stars from near-UV OH lines [PDF]

, 1998
We have performed a detailed oxygen abundance analysis of 23 metal-poor (-3 ...
Alonso A., Barbuy B., Bessell M. S., Bessell M. S., Blackwell D. E., Denissenkov P. A., Edvardsson B., Fuhrmann K., Garcia Lopez R. J., Garik Israelian, Gratton R. G., Kiselman D., Kiselman D., Lambert D. L., Nissen P. E., Nissen P. E., Pavlenko Ya. V., Piskunov N. E., Rafael Rebolo, Ramon J. Garcia Lopez, Spite M., Spite M., Stark G., Takeda Y.   +23 more
core   +2 more sources

Bewertung und Verbesserung der Biodiversität in landwirtschaftlichen Gebieten unter besonderer Berücksichtigung von Vogelarten als Bioindikatoren

Julius-Kühn-Archiv, 2013
Agricultural landscapes have crucial functions for biodiversity conservation. Contrary to the goals of biodiversity protection the habitat functions and the biological diversity are deteriorating, especially in arable areas.
Hoffmann, Jörg, Wiegand, Ina, Wittchen, Udo, Ehlert, Sigrid, Berger, Gert, Pfeffer, Holger   +5 more
doaj   +1 more source

A Model for Abundances in Metal-Poor Stars [PDF]

, 2001
It is argued that the abundances of r-process related elements in stars with -3-3. The H events are of high frequency and produce dominantly heavy (A>130) r-elements but no Fe (presumably leaving behind black holes).
G. J. Wasserburg, Gratton R. G., Magain P., Truran J. W., Y.‐Z. Qian, Zhao G.   +5 more
core   +3 more sources

Atomic diffusion in the atmosphere of Feige 86

Open Astronomy, 2017
We have revisited the ultraviolet and optical spectra of the blue horizontal branch star Feige 86. The new analysis finds the star cooler and more compact than previously determined. The IUE spectrum of Feige 86 holds numerous unidentified spectral lines
Németh Péter
doaj   +1 more source

Automated spectroscopic abundances of A and F-type stars using echelle spectrographs I. Reduction of ELODIE spectra and method of abundance determination [PDF]

, 2001
This paper presents an automated method to determine detailed abundances for A and F-type stars. This method is applied on spectra taken with the ELODIE spectrograph. Since the standard reduction procedure of ELODIE is optimized to obtain accurate radial
Adelman, Anders, Baranne, Barnard, Barnard, Blackwell, Castelli, Chmielewski, D. Erspamer, Gigas, Gray, Grevesse, Hall, Hill, Horne, Irwin, Kupka, Kurucz, Kurucz, Lemke, Lemke, Norlén, P. North, Piskunov, Qiu, Rentzsch-Holm, Sauval, Takeda, Takeda, Valenti, Varenne   +30 more
core   +3 more sources

Results of 40-year Studies of the X-Ray Binary Cyg X-1 = V1357 Cyg

Open Astronomy, 2016
This paper reviews the results of our 40-year studies of Cyg X-1 using various methods and observational data: mainly optical photometric, spectroscopic, and polarimetric ones, with X-ray data also considered.
Karitskaya E. A.
doaj   +1 more source

Akari Observations of Brown Dwarfs. II CO2 as Probe of Carbon and Oxygen Abundances in Brown Dwarfs

, 2011
Recent observations with the infrared astronomical satellite AKARI have shown that the CO2 bands at 4.2 micron in three brown dwarfs are much stronger than expected from the unified cloudy model (UCM) based on recent solar C & O abundances.
Allende Prieto, Ayres, Burgasser, Burgasser, Burgasser, Cushing, Edvardsson, Grevesse, Griffith, Issei Yamamura, Leggett, Leggett, Leggett, Marley, Noll, Oppenheimer, Satoko Sorahana, Saumon, Stephens, Takashi Tsuji, Tsuji, Tsuji, Tsuji, Vrba, Yamamura   +24 more
core   +1 more source

Determining solar abundances using helioseismology [PDF]

, 2006
The recent downward revision of solar photospheric abundances of Oxygen and other heavy elements has resulted in serious discrepancies between solar models and solar structure as determined through helioseismology.
Antia H. M., Basu S., Basu S., Basu S., Eggleton P. P., Elliott J. R., Gough D. O., H. M. Antia, Sarbani Basu   +8 more
core   +2 more sources

Nucleosynthesis Predictions and High-Precision Deuterium Measurements

Universe, 2017
Two new high-precision measurements of the deuterium abundance from absorbers along the line of sight to the quasar PKS1937–1009 were presented. The absorbers have lower neutral hydrogen column densities (N(HI) ≈ 18 cm − 2 ) than for previous ...
Signe Riemer-Sørensen, Espen Sem Jenssen   +1 more
doaj   +1 more source

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