Results 1 to 10 of about 218,860 (317)

Chemical Analysis of the Brightest Star of the Cetus II Ultrafaint Dwarf Galaxy Candidate

The Astrophysical Journal, 2023
We present a detailed chemical abundance analysis of the brightest star in the ultrafaint dwarf (UFD) galaxy candidate Cetus II from high-resolution Magellan/MIKE spectra.
K. B. Webber, T. T. Hansen, J. L. Marshall, J. D. Simon, A. B. Pace, B. Mutlu-Pakdil, A. Drlica-Wagner, C. E. Martínez-Vázquez, M. Aguena, S. S. Allam, O. Alves, E. Bertin, D. Brooks, A. Carnero Rosell, J. Carretero, L. N. da Costa, J. De Vicente, P. Doel, I. Ferrero, D. Friedel, J. Frieman, J. García-Bellido, G. Giannini, D. Gruen, R. A. Gruendl, S. R. Hinton, D. L. Hollowood, K. Honscheid, K. Kuehn, J. Mena-Fernández, F. Menanteau, R. Miquel, R. L. C. Ogando, M. E. S. Pereira, A. Pieres, A. A. Plazas Malagón, E. Sanchez, B. Santiago, J. Allyn Smith, M. Smith, E. Suchyta, G. Tarle, C. To, N. Weaverdyck, B. Yanny   +44 more
doaj   +1 more source

Understanding the Chemical Evolution of Blue Edge-on Low Surface Brightness Galaxies

The Astrophysical Journal, 2023
We present a sample of 330 blue edge-on low surface brightness galaxies (ELSBGs). To understand the chemical evolution of ELSBGs, we derived the gas-phase abundance and the [ α /Fe] ratio.
Tian-wen Cao, Hong Wu, Gaspar Galaz, Venu M. Kalari, Cheng Cheng, Zi-Jian Li, Jun-feng Wang   +6 more
doaj   +1 more source

Direct D-atom Incorporation in Radicals: An Overlooked Pathway for Deuterium Fractionation

The Astrophysical Journal, 2023
Direct D-H exchange in radicals is investigated in a quasi-uniform flow employing chirped-pulse millimeter-wave spectroscopy. Inspired by the H-atom catalyzed isomerization of C _3 H _2 reported in our previous study, D-atom reactions with the propargyl (
Nureshan Dias, Ranil M. Gurusinghe, Bernadette M. Broderick, Tom J Millar, Arthur G. Suits   +4 more
doaj   +1 more source

On the Hunt for the Origins of the Orphan–Chenab Stream: Detailed Element Abundances with APOGEE and Gaia

The Astrophysical Journal, 2023
Stellar streams in the Galactic halo are useful probes of the assembly of galaxies like the Milky Way. Many tidal stellar streams that have been found in recent years are accompanied by a known progenitor globular cluster or dwarf galaxy.
Keith Hawkins, Adrian M. Price-Whelan, Allyson A. Sheffield, Aidan Z. Subrahimovic, Rachael L. Beaton, Vasily Belokurov, Denis Erkal, Sergey E. Koposov, Richard R. Lane, Chervin F. P. Laporte, Christian Nitschelm   +10 more
doaj   +1 more source

Observing the signatures of AGB s-process nucleosynthesis in planetary nebulae: An origins story

Frontiers in Astronomy and Space Sciences, 2022
I relate an anecdotal history of the beginnings of a new initiative in studies of the chemical composition of planetary nebulae: namely, investigating abundances of elements beyond the iron-peak through infrared spectroscopy.
Harriet L. Dinerstein
doaj   +1 more source

Chemical Tracing and the Origin of Carbon in the Galactic Disk

Universe, 2022
A basic problem in studies of the evolution of chemical elements in galaxies is the uncertainties in the yields of elements produced by different types of stars.
Bengt Gustafsson
doaj   +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

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

High-resolution Chemical Abundances of the Nyx Stream

The Astrophysical Journal, 2023
Nyx is a nearby, prograde, and high-eccentricity stellar stream physically contained in the thick disk, but its origin is unknown. Nyx could be the remnant of a disrupted dwarf galaxy, in which case the associated dark matter substructure could affect ...
Shuyu Wang, Lina Necib, Alexander P. Ji, Xiaowei Ou, Mariangela Lisanti, Mithi A. C. de los Reyes, Allison L. Strom, Mimi Truong   +7 more
doaj   +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