Results 51 to 60 of about 50,982 (241)

Nuclear Chronometers [PDF]

, 2001
Observations of metal-poor Galactic halo stars indicate that the abundance pattern of the (heaviest) neutron-capture elements is consistent with the scaled solar system r-process abundances.
Cowan, J. J., Sneden, C., Truran, J. W.
core   +3 more sources

Abundances of Planetary Nebulae and Evolved Stars: Iron and Sulfur Depletion, and Carbon and Nitrogen Enrichment, in Low- and Intermediate-mass Stellar Populations in the Milky Way

The Astrophysical Journal
We research the elemental abundances in Galactic planetary nebulae (PNe) compared with those of their stellar progenitors (red giant branch and asymptotic giant branch, AGB, stars), to explore and quantify the expected—i.e., due to AGB evolution or ...
Letizia Stanghellini, Verne V. Smith, Katia Cunha, Nikos Prantzos   +3 more
doaj   +1 more source

Caught in the Act: A Metal-rich High-velocity Cloud in the Inner Galaxy

The Astrophysical Journal, 2023
We characterize the chemical and physical conditions in an outflowing high-velocity cloud (HVC) in the inner Galaxy. We report a supersolar metallicity of [O/H] = +0.36 ± 0.12 for the HVC at v _LSR = 125.6 km s ^−1 toward the star HD 156359 ( l = 328.°7,
Frances H. Cashman, Andrew J. Fox, Bart P. Wakker, Trisha Ashley, Derck Massa, Edward B. Jenkins, Dhanesh Krishnarao, Robert A. Benjamin, Rongmon Bordoloi, Tae-Sun Kim   +9 more
doaj   +1 more source

The largest oxigen bearing organic molecule repository

, 2007
We present the first detection of complex aldehydes and isomers in three typical molecular clouds located within 200pc of the center of our Galaxy. We find very large abundances of these complex organic molecules (COMs) in the central molecular zone ...
Huttemeister S., J. Martin‐Pintado, M. A. Requena‐Torres, M. R. Morris, Martin-Pintado J., Nummelin A., Rodriguez-Fernandez N. J., S. Martin, Tielens A. G. G. M.   +8 more
core   +1 more source

The abundance of argon at the galactic center

The Astrophysical Journal, 1981
Measurements of forbidden line Ar II 6.99 micron and Pf alpha 7.45 micron made from the Kuiper Airborne Observatory are presented for Sgr A, the H II region at the center of the Galaxy. These line strengths, when combined with ground-based measurements, suggest a factor of enhancement of two in the Ar/H ratio in the galactic center region relative to ...
J. D. Bregman, F. C. Witteborn, David M. Rank, D. F. Lester, Harriet L. Dinerstein   +4 more
openaire   +2 more sources

Fluorine Abundances in Local Stellar Populations

The Astronomical Journal
We present the first fluorine measurements in 12 normal K giants belonging to the Galactic thin and thick disks using spectra obtained with the Phoenix infrared spectrometer on the 2.1 m telescope at Kitt Peak. Abundances are determined from the (1−0) R9
K. E. Brady, C. A. Pilachowski, V. Grisoni, Z. G. Maas, K. A. Nault   +4 more
doaj   +1 more source

A Wide Metallicity Range for Gyr-old Stars in the Nuclear Star Cluster

The Astrophysical Journal Letters, 2023
We report metallicities for three ∼Gyr-old stars in the Milky Way nuclear star cluster (NSC) using high-resolution near-infrared spectroscopy. We derive effective temperatures from a calibration with Sc line strength, which yields results in good ...
B. Thorsbro, R. Forsberg, G. Kordopatis, A. Mastrobuono-Battisti, R. P. Church, R. M. Rich, N. Ryde, M. Schultheis, S. Nishiyama   +8 more
doaj   +1 more source

Constraining cosmic scatter in the Galactic halo through a differential analysis of metal-poor stars [PDF]

, 2017
© ESO 2017.Context. The chemical abundances of metal-poor halo stars are important to understanding key aspects of Galactic formation and evolution. Aims.
Amanda Karakas, Andrievsky, Andrievsky, Andrievsky, Andrievsky, Andrievsky, Aoki, Aoki, Arnone, Asplund, Asplund, Audouze, Baumueller, Baumueller, Bensby, Bergemann, Bergemann, Biazzo, Boesgaard, Bonifacio, Bonifacio, Busso, Busso, Carlos, Caughlan, Cayrel, Cescutti, Chiaki Kobayashi, Chiappini, Chieffi, Civitarese, Coc, Coc, Coc, Cohen, Cowan, Cyburt, Eggen, Ferraro, Ferraro, Fishlock, François, Frischknecht, Fu, Gustafsson, Hampel, Hannaford, Hansen, Hartog, Heger, Henrique Reggiani, Herwig, Hollek, Hou, Iocco, Jacobson, Ji, Jorge Meléndez, Karakas, Karakas, Keller, Kim, Kobayashi, Kobayashi, Kobayashi, Kohri, Lai, Lawler, Lind, Lind, Liu, Liu, Maeda, McCrea, McWilliam, Meléndez, Meléndez, Meléndez, Meléndez, Meyer, Meynet, Monroe, Nissen, Nissen, Nissen, Nomoto, Norris, Norris, O’Malley, Pignatari, Placco, Placco, Placco, Pllumbi, Ramírez, Ramírez, Ramírez, Ramírez, Ramírez, Ramírez, Reggiani, Richard, Roederer, Ryan, Ryan, Ryan, Salvati, Santucci, Scholz, Schuster, Searle, Shigeyama, Sills, Sitnova, Sneden, Spina, Spite, Spite, Spite, Suda, Suda, Thielemann, Tucci Maia, Tucci Maia, Umeda, Vinicius Placco, Wood, Yamada, Yi, Yong, Zhao, Önehag   +131 more
core   +3 more sources

Manganese abundances in Galactic bulge red giants [PDF]

Astronomy & Astrophysics, 2013
Manganese is mainly produced in type II SNe during explosive silicon burning, in incomplete Si-burning regions, and depends on several nucleosynthesis environment conditions, such as mass cut beween the matter ejected and falling back onto the remnant, electron and neutron excesses, mixing fallback, and explosion energy.
Barbuy, B., Hill, V., Zoccali, M., Minniti, D., Renzini, A., Ortolani, S., Gomez, A., Trévisan, M., Dutra, N.   +8 more
openaire   +11 more sources

Heavy elements Ba, La, Ce, Nd, and Eu in 56 Galactic bulge red giants [PDF]

, 2015
Aims. The aim of this work is the study of abundances of the heavy elements Ba, La, Ce, Nd, and Eu in 56 bulge giants (red giant branch and red clump) with metallicities ranging from -1.3 dex to 0.5 dex. Methods.
Barbuy, B., Gomez, A., Hill, V., Minniti, D., Ortolani, S., Van der Swaelmen, M., Zoccali, M.   +6 more
core   +3 more sources