Results 1 to 10 of about 195,329 (258)

Novae breves from magnetar giant flares: Potential probes of neutron star crusts

Astronomy & Astrophysics
Context. Matter ejected from the magnetar crust during giant flares (GFs) may undergo r-process nucleosynthesis, producing short-lived optical transients termed “novae breves”.
Zhong Jiahang, Chen Qiu-Hong, Kang Yacheng, Li Hong-Bo, Zhang Jinghao, Chen Meng-Hua, Shao Lijing   +6 more
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Direct determination of the astrophysical reaction rate of 141Pr(γ, n)140Pr at the SSRF-SLEGS

Astronomy & Astrophysics
Context. The 141Pr(γ, n) cross-section is critical to the nucleosynthesis of p-nuclides 136,138Ce in thermonuclear supernovae and in massive stars. The photonuclear reaction of 141Pr(γ, n) provides a new method for producing 140Pr radioisotopes for ...
Hu J. H., An Z. D., Hao Z. R., Li Z. C., Fan G. T., Wang H. W., Ma Y. G., Liu T., Liang H., Wen H. H., Guo C. C.   +10 more
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Impact of in situ nuclear networks and atomic opacities on neutron star merger ejecta dynamics, nucleosynthesis, and kilonovae

Astronomy & Astrophysics
Context. Binary neutron star merger (BNSM) ejecta are key sites of rapid neutron capture (r-process) nucleosynthesis and they produce kilonovae powered by the radioactive decay of freshly synthesized nuclei.
Magistrelli Fabio, Bernuzzi Sebastiano, Perego Albino, Jacobi Maximilian, Fontes Christopher J.   +4 more
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Probing millisecond magnetar formation in binary neutron star mergers through X-ray follow-up of gravitational wave alerts

Astronomy & Astrophysics
Context. The nature of the remnant of a binary neutron star (BNS) merger is uncertain. Although it certainly is a black hole in the cases of the most massive BNSs, X-ray light-curves from short gamma-ray burst afterglows suggest a neutron star (NS) as a ...
Plasse C., Reboul-Salze A., Guilet J., Götz D., Leroy N., Raynaud R., Bugli M., Dal Canton T.   +7 more
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I-Process Nucleosynthesis in AM CVn Systems

Galaxies
We investigate nucleosynthesis during very strong, non-dynamical recurrent He-flashes that are expected to occur in close binary systems hosting a carbon–oxygen white dwarf and a type-B subdwarf companion.
Luciano Piersanti, Diego Vescovi, Sergio Cristallo, Lev R. Yungelson, Eduardo Bravo, Inmaculada Dominguez, Alexandre G. Kuranov   +6 more
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Constraining r-process nucleosynthesis with multi-objective Galactic chemical evolution models

Astronomy & Astrophysics
Context. The astrophysical site(s) of the rapid neutron-capture process (r-process) remains uncertain, with competing scenarios such as neutron star mergers and magneto-rotational supernovae offering different predictions for the timing, frequency, and ...
Molero M., Arcones A., Montes F., Hansen C. J.   +3 more
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Generalized Te([O iii])–Te(He i) Discrepancies in Ionized Nebulae: Possible Evidence of Case B Deviations and Temperature Inhomogeneities

The Astrophysical Journal
The physics of recombination lines in the He i singlet system is expected to be relatively simple, supported by accurate atomic models. We examine the intensities of He i singlets λ 3614,  λ 3965,  λ 5016,  λ 6678, and  λ 7281 and the triplet He i λ 5876
J. E. Méndez-Delgado, E. D. Skillman, E. Aver, C. Morisset, C. Esteban, J. García-Rojas, K. Kreckel, N. S. J. Rogers, F. F. Rosales-Ortega, K. Z. Arellano-Córdova, S. R. Flury, E. Reyes-Rodríguez, M. Orte-García, S. Tan   +13 more
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A Systematic NLTE Study of Very Metal-poor Stars with Metallicity down to −4.3 dex. I. Global Stellar Parameters Based on High-resolution Spectra

The Astrophysical Journal
Very metal-poor (VMP) stars provide a record of the chemical composition and dynamics of the early Galaxy. Based on the high-resolution and high signal-to-noise ratio spectra from the Subaru Telescope for 103 VMP stars, in this series of papers we ...
Jianrong Shi, Gang Zhao, Shuai Liu, Zeming Zhou, Haining Li, Hongliang Yan, Sofya Alexeeva, Huawei Zhang, Wako Aoki, Tadafumi Matsuno, Jingkun Zhao, Huiling Chen, Yufu Shen   +12 more
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Gaia-Sausage-Enceladus: Lithium evolution from early red-giant-branch and main-sequence stars

Astronomy & Astrophysics
The combination of data from the Gaia satellite and large ground-based spectroscopic surveys recently led to a milestone understanding of our Galaxy’s formation history, marked by the identification of stellar remnants of the accreted Gaia-Sausage ...
Nguyen C. T., Cescutti G., Bennedik M. M., Molaro P., Magrini L., Korn A. J.   +5 more
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Detailed Chemical Abundance Analysis of the Brightest Stars in the Turranburra and Willka Yaku Stellar Streams

The Astrophysical Journal
We present a detailed chemical abundance analysis of the three brightest known stars from each of the Turranburra and Willka Yaku stellar streams using high-resolution Magellan/Magellan Inamori Kyocera Echelle spectra. Abundances for 27 elements, ranging
K. B. Webber, T. T. Hansen, J. L. Marshall, Alexander P. Ji, Ting S. Li, Gary S. Da Costa, Lara R. Cullinane, Denis Erkal, Sergey E. Koposov, Kyler Kuehn, Geraint F. Lewis, Dougal Mackey, Sarah L. Martell, Andrew B. Pace, Nora Shipp, Jeffrey D. Simpson, Zhen Wan, Daniel B. Zucker, Victor A. Alvarado, Joss Bland-Hawthorn, Guilherme Limberg, Gustavo E. Medina, Sam A. Usman   +22 more
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