Results 111 to 120 of about 426,951 (145)

A Catalog of High-confidence Very Metal-poor Stars from DESI Based on a Deep Learning Method

The Astrophysical Journal Supplement Series
Very metal-poor (VMP; [Fe/H] 
Chen Yang, Guanhong Lin, Lei Tan, Huanbin Chi, Feng Wang, Hui Deng, Ying Mei   +6 more
doaj   +1 more source

Modelling the evolution and nucleosynthesis of carbon-enhanced metal-poor stars [PDF]

, 2008
We present the results of binary population simulations of carbon-enhanced metal-poor (CEMP) stars. We show that nitrogen and fluorine are useful tracers of the origin of CEMP stars, and conclude that the observed paucity of very nitrogen-rich stars puts
Lugaro, Maria, Pols, Onno, Izzard, Robert, De Mink, Selma   +3 more
core   +1 more source

BD+44°493: Chemo-dynamical Analysis and Constraints on Companion Planetary Masses from WIYN/NEID Spectroscopy

The Astrophysical Journal
In this work, we present high-resolution ( R ∼ 100,000), high signal-to-noise ratio (S/N ∼ 800) spectroscopic observations for the well-known, bright, extremely metal-poor, carbon-enhanced star BD+44°493.
Vinicius M. Placco, Arvind F. Gupta, Felipe Almeida-Fernandes, Sarah E. Logsdon, Jayadev Rajagopal, Erika M. Holmbeck, Ian U. Roederer, John Della Costa, Pipa Fernandez, Eli Golub, Jesus Higuera, Yatrik Patel, Susan Ridgway, Heidi Schweiker   +13 more
doaj   +1 more source

Near-Infrared Spectroscopy of Carbon-Enhanced Metal-Poor Stars. I. A SOAR/OSIRIS Pilot Study

, 2007
International audienceWe report on an abundance analysis for a pilot study of seven carbon-enhanced metal-poor (CEMP) stars, based on medium-resolution optical and near-infrared spectroscopy. The optical spectra are used to estimate [Fe/H], [C/Fe], [N/Fe]
Lee, Youngsun, Thirupathi Sivarani, S. Rossi, Sivarani, Thirupathi, Marsteller, Brian, Plez, Bertrand, B. Plez, YoungSun Lee, Brian Marsteller, Beers, Timothy C., Rossi, S., Timothy C. Beers   +11 more
core   +1 more source

The DECam MAGIC Survey: Spectroscopic Follow-up of the Most Metal-poor Stars in the Distant Milky Way Halo

The Astrophysical Journal
In this work, we present high-resolution spectroscopic observations for six metal-poor stars with [Fe/H] < –3 (including one with [Fe/H] < –4), selected using narrowband Ca ii HK photometry from the DECam MAGIC Survey.
Vinicius M. Placco, Guilherme Limberg, Anirudh Chiti, Deepthi S. Prabhu, Alexander P. Ji, Fabrícia O. Barbosa, William Cerny, Andrew B. Pace, Guy S. Stringfellow, David J. Sand, Clara E. Martínez-Vázquez, Alexander H. Riley, Silvia Rossi, Noelia E. D. Noël, A. Katherina Vivas, Gustavo E. Medina, Alex Drlica-Wagner, Joanna D. Sakowska, Burçin Mutlu-Pakdil, Pol Massana, Julio A. Carballo-Bello, Yumi Choi, Denija Crnojević, Chin Yi Tan, (MAGIC & DELVE Collaborations)   +24 more
doaj   +1 more source

HE 0144–4657: A Carbon-enhanced Ultra-metal-poor Star ([Fe/H] ∼ −4.1) from the Helmi Stream Disrupted Dwarf Galaxy

The Astrophysical Journal Letters
We present the discovery of HE 0144−4657, an ultra-metal-poor, CNO-enhanced star dynamically associated with the Helmi Stream disrupted dwarf-galaxy remnant.
Vinicius M. Placco, Guilherme Limberg, Catherine R. Kennedy, Norbert Christlieb   +3 more
doaj   +1 more source

Possibility of Secondary i- and s-processes Following r-process in the Collapsar Jet

The Astrophysical Journal Letters
The slow and intermediate neutron-capture processes, s - and i -processes, are believed to occur in asymptotic giant branch stars to provide half of the heavy atomic nuclei with A ≥ 90. We suggest a possibility that certain types of outflows found in the
Zhenyu He, Toshitaka Kajino, Motohiko Kusakabe, Shan-Gui Zhou, Hiroyuki Koura, Satoshi Chiba, Haining Li, Yangming Lin   +7 more
doaj   +1 more source

How Population III Supernovae Determined the Properties of the First Galaxies

The Astrophysical Journal
Massive Population III stars can die as energetic supernovae that enrich the early Universe with metals and determine the properties of the first galaxies.
Ke-Jung Chen, Ching-Yao Tang, Daniel J. Whalen, Meng-Yuan Ho, Sung-Han Tsai, Po-Sheng Ou, Masaomi Ono   +6 more
doaj   +1 more source

Tooth-Supporting Hard Tissue Regeneration Using Biopolymeric Material Fabrication Strategies. [PDF]

Molecules, 2020
Kim MG, Park CH.
europepmc   +1 more source

Near-infrared Observations of BD+44°493 with IGRINS-2

The Astronomical Journal
We present high-resolution ( ${ \mathcal R }\sim 45,000$ ), high-signal-to-noise (S/N > 200) H - and K -band spectra of BD+44°493 obtained with the newly commissioned IGRINS-2 instrument on the Gemini North Telescope.
Vinicius M. Placco, William D. Vacca
doaj   +1 more source