Zobrazeno 1 - 10
of 1 433
pro vyhledávání: '"A. Frebel"'
Autor:
Hirai, Yutaka, Beers, Timothy C., Lee, Young Sun, Wanajo, Shinya, Roederer, Ian U., Tanaka, Masaomi, Chiba, Masashi, Saitoh, Takayuki R., Placco, Vinicius M., Hansen, Terese T., Ezzeddine, Rana, Frebel, Anna, Holmbeck, Erika M., Sakari, Charli M.
We study the formation of stars with varying amounts of heavy elements synthesized by the rapid neutron-capture process ($r$-process) based on our detailed cosmological zoom-in simulation of a Milky Way-like galaxy with an $N$-body/smoothed particle
Externí odkaz:
http://arxiv.org/abs/2410.11943
Autor:
Naidu, Rohan P., Matthee, Jorryt, Kramarenko, Ivan, Weibel, Andrea, Brammer, Gabriel, Oesch, Pascal A., Lechner, Peter, Furtak, Lukas J., Di Cesare, Claudia, Torralba, Alberto, Kotiwale, Gauri, Bezanson, Rachel, Bouwens, Rychard J., Chandra, Vedant, Claeyssens, Adélaïde, Danhaive, A. Lola, Frebel, Anna, de Graaff, Anna, Greene, Jenny E., Heintz, Kasper E., Ji, Alexander P., Kashino, Daichi, Katz, Harley, Labbe, Ivo, Leja, Joel, Li, Yijia, Maseda, Michael V., Richard, Johan, Shivaei, Irene, Simcoe, Robert A., Sobral, David, Suess, Katherine A., Tacchella, Sandro, Williams, Christina C.
Dwarf galaxies hold the key to crucial frontiers of astrophysics, however, their faintness renders spectroscopy challenging. Here we present the JWST Cycle 2 survey, All the Little Things (ALT, PID 3516), which is designed to seek late-forming Pop II
Externí odkaz:
http://arxiv.org/abs/2410.01874
Autor:
Bandyopadhyay, Avrajit, Ezzeddine, Rana, Prieto, Carlos Allende, Aria, Nima, Shah, Shivani P., Beers, Timothy C., Frebel, Anna, Hansen, Terese T., Holmbeck, Erika M., Placco, Vinicius M., Roederer, Ian U., Sakari, Charli M.
Publikováno v:
The Astrophysical Journal Supplement , 2024, Volume 274, Number 2, Page 39
Understanding the abundance pattern of metal-poor stars and the production of heavy elements through various nucleosynthesis processes offers crucial insights into the chemical evolution of the Milky Way, revealing primary sites and major sources of
Externí odkaz:
http://arxiv.org/abs/2408.03731
Autor:
Roederer, Ian U., Beers, Timothy C., Hattori, Kohei, Placco, Vinicius M., Hansen, Terese T., Ezzeddine, Rana, Frebel, Anna, Holmbeck, Erika M., Sakari, Charli M.
We present stellar parameters and chemical abundances of 47 elements detected in the bright (V = 11.63) very metal-poor ([Fe/H] = -2.20 +- 0.12) star 2MASS J22132050-5137385. We observed this star using the Magellan Inamori Kyocera Echelle spectrogra
Externí odkaz:
http://arxiv.org/abs/2406.02691
Autor:
Andales, Hillary Diane, Figueiredo, Ananda Santos, Fienberg, Casey Gordon, Mardini, Mohammad K., Frebel, Anna
We present a detailed chemical abundance and kinematic analysis of six extremely metal-poor ($-4.2 \leq$ [Fe/H] $\leq-$2.9) halo stars with very low neutron-capture abundances ([Sr/H] and [Ba/H]) based on high-resolution Magellan/MIKE spectra. Three
Externí odkaz:
http://arxiv.org/abs/2405.07856
Neutron star mergers (NSMs) produce copious amounts of heavy r-process elements after a time delayed inspiral process. Once NSMs are present in a galaxy, r-process elements, such as Eu, are expected to significantly increase with time. Yet, there has
Externí odkaz:
http://arxiv.org/abs/2404.10067
Autor:
Burdge, Kevin B., El-Badry, Kareem, Kara, Erin, Canizares, Claude, Chakrabarty, Deepto, Frebel, Anna, Millholland, Sarah C., Rappaport, Saul, Simcoe, Rob, Vanderburg, Andrew
Evidence suggests that when compact objects such as black holes and neutron stars form, they may receive a ``natal kick,'' where the stellar remnant gains momentum. Observational evidence for neutron star kicks is substantial, yet limited for black h
Externí odkaz:
http://arxiv.org/abs/2404.03719
Autor:
Xylakis-Dornbusch, T., Hansen, T. T., Beers, T. C., Christlieb, N., Ezzeddine, R., Frebel, A., Holmbeck, E., Placco, V. M., Roederer, I. U., Sakari, C. M., Sneden, C.
Context. In recent years, the R-Process Alliance (RPA) has conducted a successful search for stars enhanced in elements produced by the rapid neutron-capture (r-)process. In particular, the RPA has uncovered a number of stars strongly enriched in lig
Externí odkaz:
http://arxiv.org/abs/2404.03379
Autor:
Ou, Xiaowei, Chiti, Anirudh, Shipp, Nora, Simon, Joshua D., Geha, Marla, Frebel, Anna, Mardini, Mohammad K., Erkal, Denis, Necib, Lina
The Hercules ultra-faint dwarf galaxy (UFD) has long been hypothesized to be tidally disrupting, yet no conclusive evidence has been found for tidal disruption owing partly to difficulties in identifying Hercules member stars. In this work, we presen
Externí odkaz:
http://arxiv.org/abs/2403.00921
We report on the discovery of the first ultra metal-poor (UMP) star 2MASS~J20500194$-$6613298 (J2050$-$6613; \mbox{[Fe/H] = $-4.05$}) selected from the Gaia BP/RP spectral catalog that belongs to the ancient Atari disk component. We obtained a high-r
Externí odkaz:
http://arxiv.org/abs/2402.07046