Results 141 to 150 of about 56,706 (218)

Spectacular Nucleosynthesis from Early Massive Stars

The Astrophysical Journal Letters
Stars that formed with an initial mass of over 50 M _⊙ are very rare today, but they are thought to be more common in the early Universe. The fates of those early, metal-poor, massive stars are highly uncertain.
Alexander P. Ji, Sanjana Curtis, Nicholas Storm, Vedant Chandra, Kevin C. Schlaufman, Keivan G. Stassun, Alexander Heger, Marco Pignatari, Adrian M. Price-Whelan, Maria Bergemann, Guy S. Stringfellow, Carla Fröhlich, Henrique Reggiani, Erika M. Holmbeck, Jamie Tayar, Shivani P. Shah, Emily J. Griffith, Chervin F. P. Laporte, Andrew R. Casey, Keith Hawkins, Danny Horta, William Cerny, Pierre Thibodeaux, Sam A. Usman, João A. S. Amarante, Rachael L. Beaton, Phillip A. Cargile, Cristina Chiappini, Charlie Conroy, Jennifer A. Johnson, Juna A. Kollmeier, Haining Li, Sarah Loebman, Georges Meynet, Dmitry Bizyaev, Joel R. Brownstein, Pramod Gupta, Sean Morrison, Kaike Pan, Solange V. Ramirez, Hans-Walter Rix, José Sánchez-Gallego   +41 more
doaj   +1 more source

Stellar Abundances for Galactic Archaeology Database. IV. Compilation of stars in dwarf galaxies [PDF]

, 2017
Takuma Suda, Jun Hidaka, Wako Aoki, Yutaka Katsuta, Shimako Yamada, Masayuki Y. Fujimoto, Yukari Ohtani, Miyu Masuyama, Kazuhiro Noda, Kentaro Wada   +9 more
openalex   +1 more source

oMEGACat. V. Helium Enrichment in ω Centauri as a Function of Metallicity

The Astrophysical Journal
Constraining the helium enhancement in stars is critical for understanding the formation mechanisms of multiple populations in star clusters. However, measuring helium variations for many stars within a cluster remains observationally challenging. We use
C. Clontz, A. C. Seth, Z. Wang, S. O. Souza, M. Häberle, M. S. Nitschai, N. Neumayer, M. Latour, A. P. Milone, A. Feldmeier-Krause, N. Kacharov, M. Libralato, A. Bellini, G. van de Ven, M. Alfaro-Cuello   +14 more
doaj   +1 more source

Realising the potential of large spectroscopic surveys with machine-learning [PDF]

arXiv
Machine-learning is playing an increasing role in helping the astronomical community to face data analysis challenges, in particular in the field of Galactic Archaeology and large scale spectroscopic surveys. We present recent developments in the field of convolutional neural-networks (CNNs) for stellar abundances in the context of the Galactic ...
arxiv  

Galactic Archaeology in the Era of Large Surveys

, 2020
In this Thesis, I study the formation and chemical evolution of the Milky Way by means of new and detailed chemical evolution models in the light of the most recent data from Galactic surveys and missions. Indeed, we are in a golden era for Galactic Archaeology thanks to the advent of several Galactic spectroscopic surveys and missions.
openaire   +1 more source

Galactic Archaeology in the Local Group

, 2020
We are in the age of advanced surveys and simulations which have greatly expanded our understanding of the large scale evolution of the universe, but have also revealed many contradictions at small scale. Limitations of our simulations make it difficult to resolve faint substructures in Local Group analogs, hence we resort to observations which now ...
openaire   +1 more source

Uncertainty of Line-of-sight Velocity Measurements of Faint Stars from Low- and Medium-resolution Optical Spectra

The Astronomical Journal
Massively multiplexed spectrographs will soon gather large statistical samples of stellar spectra. The accurate estimation of uncertainties on derived parameters, such as the line-of-sight velocity v _los , especially for spectra with low signal-to-noise
László Dobos, Alexander S. Szalay, Tamás Budavári, Evan N. Kirby, Robert H. Lupton, Rosemary F. G. Wyse   +5 more
doaj   +1 more source

Applying machine learning to Galactic Archaeology: how well can we recover the origin of stars in Milky Way-like galaxies? [PDF]

Andrea Sante, Andreea S. Font, Sandra Ortega‐Martorell, Iván Olier, Ian G. McCarthy   +4 more
openalex   +3 more sources

Precision Stellar Astrophysics and Galactic Archaeology: 2020

, 2019
This white paper is meant to capture many different elements of stellar astrophysics and galactic archaeology that highlight the important role this science will play in the 2020s era of precision astronomy.
Kollmeier, J., Fuller, J., Gaensicke, B., Gaudi, S., Nataf, D., Rix, H.-W., Aerts, C., Anderson, S., Anderson, L., Anguiano, B., Basu, S., Bird, J., Brown, A., Bullock, J., Cunha, K., Lee, N.D., Hekker, S., Johnson, J., Lane, R., Ness, M., Pinsonneault, M.H., Schwope, A., Aguirre, V.S., Steinmetz, M., Stevens, D.J., Teske, J., Tkachenko, A., Stassun, K., Ting, Y.-S., Stutz, A., Weinberg, D.H., Zasowski, G.   +31 more
openaire   +3 more sources

An Actinide-boost Star Discovered in the Gaia-Sausage-Enceladus

The Astrophysical Journal Letters
We report the discovery of an actinide-boost, very metal-poor ( $\left[{\rm{Fe}}/{\rm{H}}\right]=-2.38$ ), r -process-enhanced ( $\left[{\rm{Eu}}/{\rm{Fe}}\right]=0.80$ ) star, LAMOST J0804+5740, within the Gaia-Sausage-Enceladus (GSE). Based on the high-
Yangming Lin, Haining Li, Ruizheng Jiang, Wako Aoki, Satoshi Honda, Zhenyu He, Ruizhi Zhang, Zhuohan Li, Gang Zhao   +8 more
doaj   +1 more source