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Related papers: $^{180}$Ta production in the classical s-process

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Around half of the heavy elements in the universe are formed through the slow neutron capture (s-) process, which takes place in thermally pulsing asymptotic giant branch (AGB) stars with masses $1-6\;M_{\odot}$. The nucleosynthetic imprint…

Solar and Stellar Astrophysics · Physics 2024-11-06 A. J. Dimoff , C. J. Hansen , R. J. Stancliffe , B. Kubatova , I. Stateva , A. Kucinskas , V. Dobrovolskas

Accurate enthalpies of formation are reported for known and potential astromolecules using high level ab initio quantum chemical calculations. A total of 130 molecules comprising of 31 isomeric groups and 24 cyanide/isocyanide pairs with…

Astrophysics of Galaxies · Physics 2016-10-03 Emmanuel E. Etim , Elangannan Arunan

The decomposition of the Solar system abundances of heavy isotopes into their s- and r- components plays a key role in our understanding of the corresponding nuclear processes and the physics and evolution of their astrophysical sites. We…

Astrophysics of Galaxies · Physics 2020-01-08 N. Prantzos , C. Abia , S. Cristallo , M. Limongi , A. Chieffi

73Ge(n,g) cross sections were measured at the neutron time-of-flight facility n_TOF at CERN up to neutron energies of 300 keV, providing for the first time experimental data above 8 keV. Results indicate that the stellar cross section at kT…

Nuclear Experiment · Physics 2019-02-22 Claudia Lederer-Woods

The production of the heavy stable proton-rich isotopes between 74Se and 196Hg -- the p nuclides -- is due to the contribution from different nucleosynthesis processes, activated in different types of stars. Whereas these processes have…

Solar and Stellar Astrophysics · Physics 2018-02-09 C. Travaglio , T. Rauscher , A. Heger , M. Pignatari , C. West

From newly-obtained high-resolution, high signal-to-noise ratio spectra the abundances of the elements La and Eu have been determined over the stellar metallicity range -3<[Fe/H]<+0.3 in 159 giant and dwarf stars. Lanthanum is predominantly…

Astrophysics · Physics 2009-11-10 J. Simmerer , C. Sneden , J. J. Cowan , J. Collier , V. M. Woolf , J. E. Lawler

The photoneutron reaction $^{181}\rm{Ta}(\gamma,3n)^{178m,g}\rm{Ta}$ was investigated with the beam from the NSC KIPT electron linear accelerator LUE-40. The measurements were performed using the residual $\gamma$-activity method. The…

Nuclear Experiment · Physics 2022-01-26 O. S. Deiev , I. S. Timchenko , S. N. Olejnik , V. A. Kushnir , V. V. Mytrochenko , S. A. Perezhogin

The heavy elements formed by neutron capture processes have an interesting history from which we can extract useful clues to and constraints upon both the characteristics of the processes themselves and the star formation and…

Astrophysics · Physics 2009-11-07 J. W. Truran , J. J. Cowan , C. A. Pilachowski , C. Sneden

We follow the chemical evolution of the Galaxy for elements from Ba to Eu, using an evolutionary model suitable to reproduce a large set of Galactic (local and non local) and extragalactic constraints. Input stellar yields for neutron-rich…

Astrophysics · Physics 2009-10-31 C. Travaglio , D. Galli , R. Gallino , M. Busso , F. Ferrini , O. Straniero

Assuming a Salpeter initial mass function and taking the solar abundances as a representative sample, we explore the sensitivity of nucleosynthesis in massive stars to the truncation of supernova explosions above a certain mass. It is…

Solar and Stellar Astrophysics · Physics 2015-06-15 Justin M. Brown , S. E. Woosley

Recent observations of the space distribution of quasars indicate a very notable peak in space density at a redshift of $2$ to $3$.It is pointed out in this article that this may be the result of a phase transition which has a critical…

Astrophysics · Physics 2010-11-01 Anupam Singh

Abundances of low-metallicity stars offer a unique opportunity to understand the contribution and conditions of the different processes that synthesize heavy elements. Many old, metal-poor stars show a robust abundance pattern for elements…

Solar and Stellar Astrophysics · Physics 2015-01-12 C. J. Hansen , F. Montes , A. Arcones

We investigate the rates of production and thermalization of $\nu_\mu$ and $\nu_\tau$ neutrinos at temperatures and densities relevant to core-collapse supernovae and protoneutron stars. Included are contributions from electron scattering,…

Astrophysics · Physics 2008-11-26 Todd A. Thompson , Adam Burrows , J. E. Horvath

The uncertainty in the 29P(p,gamma)30S reaction rate over the temperature range of 0.1 - 1.3 GK was previously determined to span ~4 orders of magnitude due to the uncertain location of two previously unobserved 3+ and 2+ resonances in the…

We evaluate two dominant nuclear reaction rates and their uncertainties that affect 44Ti production in explosive nucleosynthesis. Experimentally we develop thick-target yields for the 40Ca(alpha,gamma)44Ti reaction at E(alpha) = 4.13, 4.54,…

We measured $^{35}$Cl abundances in 52 M giants with metallicities between -0.5 $<$ [Fe/H] $<$ 0.12. Abundances and atmospheric parameters were derived using infrared spectra from CSHELL on the IRTF and from optical echelle spectra. We…

Solar and Stellar Astrophysics · Physics 2021-03-16 Z. G. Maas , C. A. Pilachowski

The impact of a kination-dominated phase generated by a quintessential exponential model on the thermal abundance of gravitinos and axinos is investigated. We find that their abundances become proportional to the transition temperature from…

High Energy Physics - Phenomenology · Physics 2009-07-20 M. E. Gomez , S. Lola , C. Pallis , J. Rodriguez-Quintero

We study the s-process abundances (A > 90) at the epoch of the solar-system formation. AGB yields are computed with an updated neutron capture network and updated initial solar abundances. We confirm our previous results obtained with a…

Solar and Stellar Astrophysics · Physics 2015-06-19 S. Bisterzo , C. Travaglio , R. Gallino , M. Wiescher , F. Käppeler

We present a detailed study of s-process nucleosynthesis in massive stars of solar-like initial composition and masses 15, 20,25, and 30 Msun. We update our previous results of s-process nucleosynthesis during the core He-burning of these…

Astrophysics · Physics 2008-11-26 Lih-Sin The , Mounib F. El Eid , Bradley S. Meyer

According to standard models supernovae produce radioactive $^{44}$Ti, which should be visible in gamma-rays following decay to $^{44}$Ca for a few centuries. $^{44}Ti production is believed to be the source of cosmic $^{44}$Ca, whose…