Results 41 to 50 of about 59,850 (232)

Search for Extremely Metal-poor Stars with Gemini-N/Graces. I. Chemical-abundance Analysis

The Astrophysical Journal, 2023
We present stellar parameters and abundances of 13 elements for 18 very metal-poor (VMP; [Fe/H] < –2.0) stars, selected as extremely metal-poor (EMP; [Fe/H] < –3.0) candidates from the Sloan Digital Sky Survey and Large sky Area Multi-Object Fiber ...
Miji Jeong, Young Sun Lee, Timothy C. Beers, Vinicius M. Placco, Young Kwang Kim, Jae-Rim Koo, Ho-Gyu Lee, Soung-Chul Yang   +7 more
doaj   +1 more source

Continuous star formation in IZw18

, 2004
We study the dynamical and chemical evolution of a galaxy similar to IZw18 under the assumption of a continuous star formation during bursts. We adopt a 2-D hydrocode coupled with detailed chemical yields originating from SNeII, SNeIa and from single ...
A. D'Ercole, Aloisi, Aloisi, Aloisi, Alvensleben, Anders, Argast, Brown, Cannon, Carigi, Chiappini, Chiappini, D'Ercole, Davidson, Davidson, de Avillez, de Mello, De Young, Dufour, Dufour, Dufour, Ehlerová, F. Matteucci, French, Fryer, Fryer, Garnett, Garnett, Grebel, Greggio, Greggio, Henry, Hirashita, Holweger, Hunt, Hunter, Izotov, Izotov, Izotov, Kinman, Kobayashi, Kobayashi, Koo, Kroupa, Kroupa, Kroupa, Kunth, Kunth, Kunth, Kunth, Larsen, Larsen, Lecavelier des Etangs, Legrand, Legrand, Legrand, Legrand, Leitherer, Lequeux, Lequeux, Levshakov, M. Tosi, MacLow, Marcolini, Martin, Martin, Mas-Hesse, Matsumoto, Matteucci, Matteucci, Matteucci, Matteucci, Melioli, Meurer, Meynet, Pagel, Papaderos, Pettini, Pipino, Recchi, Recchi, Renzini, S. Recchi, Salpeter, Sargent, Scalo, Searle, Silich, Skillman, Strickland, Strickland, Summers, Takeuchi, Theis, Thuan, Timmes, Vallenari, van den Hoek, van Zee, Vanzi, Vorobyov, Vílchez, Weaver, Woosley, Zwicky, Östlin   +105 more
core   +1 more source

A Bifunctional T3SS‐Effector Simultaneously Cleaves Host MAP Kinase and Inhibits PPM1A Phosphatase

Advanced Science, EarlyView.
Pathogenic bacteria exploit the metalloprotease effector NleD to subvert host defenses. Structural, biochemical, and infection analyses reveal a bifunctional mechanism by which NleD binds and inhibits the host phosphatase PPM1A while preserving its proteolytic activity against MAPKs.
Yaakov Socol, Lihi Gur‐Arie, Netanel Tzarum, Tamara Wellins, Naama Katsowich, Miriam Ravins, Michal Bejerano‐Sagie, Klil Cohen, Oded Livnah, Joshua N. Adkins, Ernesto Nakayasu, Alexei Savchenko, Yeu Khai Choong, Nikhil Kumar Tulsian, Saturo Machida, Sigal Ben‐Yehuda, Yael Litvak, J. Sivaraman, Ilan Rosenshine   +18 more
wiley   +1 more source

Modeling the Ages and Chemical Abundances of Elliptical Galaxies

The Astrophysical Journal
Spectroscopic studies of elliptical galaxies show that their stellar population ages, mean metallicity, and α enhancement traced by [Mg/Fe] all increase with galaxy stellar mass or velocity dispersion.
Nicole Marcelina Gountanis, David H. Weinberg, Aliza G. Beverage, Nathan R. Sandford, Charlie Conroy, Mariska Kriek   +5 more
doaj   +1 more source

The Chemical Evolution of the Galaxy: the two-infall model [PDF]

, 1996
In this paper we present a new chemical evolution model for the Galaxy which assumes two main infall episodes for the formation of halo-thick disk and thin disk, respectively. We do not try to take into account explicitly the evolution of the halo but we
C., Chiappini, F., Gratton, Matteucci, R.   +5 more
core   +2 more sources

Chemical evolution of high-redshift radio galaxies [PDF]

Astronomy & Astrophysics, 2009
We present new deep optical spectra of 9 high-z radio galaxies (HzRGs) at z > 2.7 obtained with FORS2 on VLT. These rest-frame ultraviolet spectra are used to infer the metallicity of the narrow-line regions (NLRs) in order to investigate the chemical evolution of galaxies in high-z universe. We focus mainly on the CIV/HeII and CIII]/CIV flux ratios
K. Matsuoka, T. Nagao, R. Maiolino, MARCONI, ALESSANDRO, Y. Taniguchi   +4 more
openaire   +3 more sources

Solid Harmonic Wavelet Bispectrum for Image Analysis

Advanced Science, EarlyView.
The Solid Harmonic Wavelet Bispectrum (SHWB), a rotation‐ and translation‐invariant descriptor that captures higher‐order (phase) correlations in signals, is introduced. Combining wavelet scattering, bispectral analysis, and group theory, SHWB achieves interpretable, data‐efficient representations and demonstrates competitive performance across texture,
Alex Brown, Mathilda Avirett‐Mackenzie, Carolin Villforth, Georgios Exarchakis   +3 more
wiley   +1 more source

The Next Generation Deep Extragalactic Exploratory Public (NGDEEP) Survey

The Astrophysical Journal Letters
We present the Next Generation Deep Extragalactic Exploratory Public (NGDEEP) Survey, a deep slitless spectroscopic and imaging Cycle 1 JWST treasury survey designed to constrain feedback mechanisms in low-mass galaxies across cosmic time. NGDEEP targets
Micaela B. Bagley, Nor Pirzkal, Steven L. Finkelstein, Casey Papovich, Danielle A. Berg, Jennifer M. Lotz, Gene C. K. Leung, Henry C. Ferguson, Anton M. Koekemoer, Mark Dickinson, Jeyhan S. Kartaltepe, Dale D. Kocevski, Rachel S. Somerville, L. Y. Aaron Yung, Bren E. Backhaus, Caitlin M. Casey, Marco Castellano, Óscar A. Chávez Ortiz, Katherine Chworowsky, Isabella G. Cox, Romeel Davé, Kelcey Davis, Vicente Estrada-Carpenter, Adriano Fontana, Seiji Fujimoto, Jonathan P. Gardner, Mauro Giavalisco, Andrea Grazian, Norman A. Grogin, Nimish P. Hathi, Taylor A. Hutchison, Anne E. Jaskot, Intae Jung, Lisa J. Kewley, Allison Kirkpatrick, Rebecca L. Larson, Jasleen Matharu, Priyamvada Natarajan, Laura Pentericci, Pablo G. Pérez-González, Swara Ravindranath, Barry Rothberg, Russell Ryan, Lu Shen, Raymond C. Simons, Gregory F. Snyder, Jonathan R. Trump, Stephen M. Wilkins   +47 more
doaj   +1 more source

JINA-NuGrid Galactic Chemical Evolution Pipeline

, 2016
Galactic chemical evolution is a topic that involves nuclear physics, stellar evolution, galaxy evolution, observation, and cosmology. Continuous communication and feedback between these fields is a key component in improving our understanding of how ...
Côté, Benoit, Fryer, Chris L., Herwig, Falk, Jones, Samuel, O'Shea, Brian W., Pignatari, Marco, Ritter, Christian, Silvia, Devin   +7 more
core   +1 more source

Chemical evolution of the Small Magellanic Cloud based on planetary nebulae [PDF]

, 2007
We investigate the chemical evolution of the Small Magellanic Cloud (SMC) based on abundance data of planetary nebulae (PNe). The main goal is to investigate the time evolution of the oxygen abundance in this galaxy by deriving an age-metallicity ...
Allende-Prieto, Aller, Anders, Asplund, Bertelli, Boroson, Cardelli, Cazetta, Chiappini, Costa, Da Costa, de Freitas Pacheco, Dolphin, Dopita, Dufour, Escudero, Feast, Girardi, Harris, Henry, Hilditch, Hill, Kaler, Keller, Kingdon, Kingsburgh, Lanfranchi, Leisy, Leisy, Maciel, Meatheringham, Meatheringham, Meatheringham, Meyssonnier, Monk, Olszewski, Osmer, Pagel, Peimbert, Piatti, Piatti, Péquignot, R. D. D. Costa, Rola, Russell, Stanghellini, Stasinska, T. P. Idiart, van den Bergh, Vassiliadis, Vassiliadis, W. J. Maciel, Webster, Wood   +53 more
core   +1 more source