All Outputs (134)

The production of proton-rich isotopes beyond iron: The γ-process in stars (2016)
Journal Article
Pignatari, M., Göbel, K., Reifarth, R., & Travaglio, C. (2016). The production of proton-rich isotopes beyond iron: The γ-process in stars. International Journal of Modern Physics E, 25(4), Article 1630003. https://doi.org/10.1142/S0218301316300034

© 2016 World Scientific Publishing Company. Beyond iron, a small fraction of the total abundances in the Solar System is made of proton-rich isotopes, the p-nuclei. The clear understanding of their production is a fundamental challenge for nuclear as... Read More about The production of proton-rich isotopes beyond iron: The γ-process in stars.

STELLAR ORIGINS OF EXTREMELY C-13- AND N-15-ENRICHED PRESOLAR SIC GRAINS: NOVAE OR SUPERNOVAE? (2016)
Journal Article
Liu, N., Nittler, L. R., Alexander, C. M. O., Wang, J., Pignatari, M., José, J., & Nguyen, A. (2016). STELLAR ORIGINS OF EXTREMELY C-13- AND N-15-ENRICHED PRESOLAR SIC GRAINS: NOVAE OR SUPERNOVAE?. The Astrophysical journal, 820(2), 1-14. https://doi.org/10.3847/0004-637X/820/2/140

Extreme excesses of 13C (12C/13C < 10) and 15N (14N/15N < 20) in rare presolar SiC grains have been considered diagnostic of an origin in classical novae, though an origin in core collapse supernovae (CCSNe) has also been proposed. We report C, N, an... Read More about STELLAR ORIGINS OF EXTREMELY C-13- AND N-15-ENRICHED PRESOLAR SIC GRAINS: NOVAE OR SUPERNOVAE?.

First direct measurement of 12C (12C,n) 23Mg at stellar energies (2016)
Journal Article
Tang, X., Bucher, B., Fang, X., Heger, A., Almaraz-Calderon, S., Alongi, A., Ayangeakaa, A., Beard, M., Best, A., Browne, J., Cahillane, C., Couder, M., DeBoer, R., Kontos, A., Lamm, L., Li, Y., Long, A., Lu, W., Lyons, S., Notani, M., …Woosley, S. (2016). First direct measurement of 12C (12C,n) 23Mg at stellar energies. EPJ Web of Conferences, 109, 04009. https://doi.org/10.1051/epjconf/201610904009

© 2016 Owned by the authors, published by EDP Sciences. Neutrons produced by the carbon fusion reaction12C(12C,n)23Mg play an important role in stellar nucleosynthesis. Past studies have shown large discrepancies between experimental data and theory,... Read More about First direct measurement of 12C (12C,n) 23Mg at stellar energies.

Iron-group abundances in the metal-poor main-sequence turnoff star HD 84937 (2016)
Journal Article
Sneden, C., Cowan, J. J., Kobayashi, C., Pignatari, M., Lawler, J. E., Den Hartog, E. A., & Wood, M. P. (2016). Iron-group abundances in the metal-poor main-sequence turnoff star HD 84937. The Astrophysical journal, 817(1), 53. https://doi.org/10.3847/0004-637x/817/1/53

We have derived new, very accurate abundances of the Fe-group elements Sc through Zn (Z = 21−30) in the bright main-sequence turnoff star HD 84937 based on high-resolution spectra covering the visible and ultraviolet spectral regions. New or recent l... Read More about Iron-group abundances in the metal-poor main-sequence turnoff star HD 84937.

Origin of the p-process radionuclides ⁹²Nb and ¹⁴⁶Sm in the early solar system and inferences on the birth of the Sun (2016)
Journal Article
Lugaro, M., Pignatari, M., Ott, U., Zuber, K., Travaglio, C., Gyürky, G., & Fülöp, Z. (2016). Origin of the p-process radionuclides ⁹²Nb and ¹⁴⁶Sm in the early solar system and inferences on the birth of the Sun. Proceedings of the National Academy of Sciences of the United States of America, 113(4), 907-912. https://doi.org/10.1073/pnas.1519344113

The abundances of ⁹²Nb and ¹⁴⁶Sm in the early solar system are determined from meteoritic analysis, and their stellar production is attributed to the p process. We investigate if their origin from thermonuclear supernovae deriving from the explosion... Read More about Origin of the p-process radionuclides ⁹²Nb and ¹⁴⁶Sm in the early solar system and inferences on the birth of the Sun.

Experiments with neutron beams for the astrophysical s process (2016)
Journal Article
Lederer, C., Altstadt, S., Andrzejewski, J., Audouin, L., Barbagallo, M., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Bosnar, D., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., Chin, M., …Žugec, P. (2016). Experiments with neutron beams for the astrophysical s process. Journal of Physics: Conference Series, 665(1), 012020. https://doi.org/10.1088/1742-6596/665/1/012020

© Published under licence by IOP Publishing Ltd. Neutron capture cross sections are the key nuclear physics input to study the slow neutron capture process, which is responsible for forming about half of the elemental abundances above Fe. Stellar neu... Read More about Experiments with neutron beams for the astrophysical s process.

Sensitivity study for s process nucleosynthesis in AGB stars (2016)
Journal Article
Koloczek, A., Thomas, B., Glorius, J., Plag, R., Pignatari, M., Reifarth, R., Ritter, C., Schmidt, S., & Sonnabend, K. (2016). Sensitivity study for s process nucleosynthesis in AGB stars. Atomic Data and Nuclear Data Tables, 108(March), 1-14. https://doi.org/10.1016/j.adt.2015.12.001

In this paper we present a large-scale sensitivity study of reaction rates in the main component of the s process. The aim of this study is to identify all rates, which have a global effect on the s process abundance distribution and the three most i... Read More about Sensitivity study for s process nucleosynthesis in AGB stars.

s-process production in rotating massive stars at solar and low metallicities (2015)
Journal Article
Frischknecht, U., Hirschi, R., Pignatari, M., Maeder, A., Meynet, G., Chiappini, C., Thielemann, F.-K., Rauscher, T., Georgy, C., & Ekström, S. (2016). s-process production in rotating massive stars at solar and low metallicities. Monthly notices of the Royal Astronomical Society, 456(2), 1803-1825. https://doi.org/10.1093/mnras/stv2723

Rotation was shown to have a strong impact on the structure and light element nucleosynthesis in massive stars. In particular, models including rotation can reproduce the primary nitrogen observed in halo extremely metal poor (EMP) stars. Additional... Read More about s-process production in rotating massive stars at solar and low metallicities.

H ingestion into He-burning convection zones in super-AGB stellar models as a potential site for intermediate neutron-density nucleosynthesis (2015)
Journal Article
Jones, S., Ritter, C., Herwig, F., Fryer, C., Pignatari, M., Bertolli, M. G., & Paxton, B. (2016). H ingestion into He-burning convection zones in super-AGB stellar models as a potential site for intermediate neutron-density nucleosynthesis. Monthly notices of the Royal Astronomical Society, 455(4), 3848-3863. https://doi.org/10.1093/mnras/stv2488

We investigate the evolution of super-AGB (SAGB) thermal pulse (TP) stars for a range of metallicities (Z) and explore the effect of convective boundary mixing (CBM). With decreasing metallicity and evolution along the TP phase, the He-shell flash an... Read More about H ingestion into He-burning convection zones in super-AGB stellar models as a potential site for intermediate neutron-density nucleosynthesis.

Mn abundances in the stars of the Galactic disc with metallicities -1.0 < [Fe/H] < 0.3 (2015)
Journal Article
Mishenina, T., Gorbaneva, T. I., Pignatari, M., Thielemann, F.-K., & Korotin, S. (2015). Mn abundances in the stars of the Galactic disc with metallicities -1.0 < [Fe/H] < 0.3. Monthly notices of the Royal Astronomical Society, 454(2), 1585-1594. https://doi.org/10.1093/mnras/stv2038

In this work we present and discuss the observations of the Mn abundances for 247 FGK dwarfs, located in the Galactic disc with metallicity -1 < [Fe/H]< +0.3. The observed stars belong to the substructures of the Galaxy thick and thin discs, and to t... Read More about Mn abundances in the stars of the Galactic disc with metallicities -1.0 < [Fe/H] < 0.3.

Carbon-rich presolar grains from massive stars : subsolar ¹²C/¹³C and ¹⁴N/¹⁵N ratios and the mystery of ¹⁵N (2015)
Journal Article
Pignatari, M., Zinner, E., Hoppe, P., J. Jordan, C., K. Gibson, B., Trappitsch, R., Herwig, F., Fryer, C., Hirschi, R., & X. Timmes, F. (2015). Carbon-rich presolar grains from massive stars : subsolar ¹²C/¹³C and ¹⁴N/¹⁵N ratios and the mystery of ¹⁵N. Astrophysical journal. Letters, 808(2), L43. https://doi.org/10.1088/2041-8205/808/2/L43

Carbon-rich grains with isotopic anomalies compared to the Sun are found in primitive meteorites. They were made by stars, and carry the original stellar nucleosynthesis signature. Silicon carbide grains of Type X and C and low-density (LD) graphites... Read More about Carbon-rich presolar grains from massive stars : subsolar ¹²C/¹³C and ¹⁴N/¹⁵N ratios and the mystery of ¹⁵N.

Erratum: Stellar neutron capture cross sections ofNe20,21,22[Phys. Rev. C90, 045804 (2014)] (2015)
Journal Article
Heil, M., Plag, R., Uberseder, E., Gallino, R., Bisterzo, S., Juseviciute, A., Käppeler, F., Lederer, C., Mengoni, A., & Pignatari, M. (2015). Erratum: Stellar neutron capture cross sections ofNe20,21,22[Phys. Rev. C90, 045804 (2014)]. Physical Review C - Nuclear Physics, 92(1), Article 019902. https://doi.org/10.1103/physrevc.92.019902

Erratum: Ni 62 (n,γ) and Ni 63 (n,γ) cross sections measured at the n-TOF facility at CERN [Phys. Rev. C (2014) 89 (025810)] (2015)
Journal Article
Tsinganis, A., Tassan-Got, L., Tarrío, D., Tain, J. L., Tagliente, G., Schmidt, S., Schillebeeckx, P., Lederer, C., Massimi, C., Berthoumieux, E., Colonna, N., Dressler, R., Guerrero, C., Gunsing, F., Käppeler, F., Kivel, N., Pignatari, M., Reifarth, R., Schumann, D., Wallner, A., …Sarmento, R. (2015). Erratum: Ni 62 (n,γ) and Ni 63 (n,γ) cross sections measured at the n-TOF facility at CERN [Phys. Rev. C (2014) 89 (025810)]. Physical Review C - Nuclear Physics, 92(1), Article 019903. https://doi.org/10.1103/physrevc.92.019903

Galactic evolution of rapid neutron capture process abundances: The inhomogeneous approach (2015)
Journal Article
Wehmeyer, B., Pignatari, M., & Thielemann, F.-K. (2015). Galactic evolution of rapid neutron capture process abundances: The inhomogeneous approach. Monthly notices of the Royal Astronomical Society, 452(2), 1970-1981. https://doi.org/10.1093/mnras/stv1352

For the origin of heavy r-process elements, different sources have been proposed, e.g., core-collapse supernovae or neutron star mergers. Old metal-poor stars carry the signature of the astrophysical source(s). Among the elements dominantly made by t... Read More about Galactic evolution of rapid neutron capture process abundances: The inhomogeneous approach.

The first direct measurement of ¹²C (¹²C,n) ²³Mg at stellar energies (2015)
Journal Article
Bucher, B., Tang, X. D., Fang, X., Heger, A., Alamaraz-Calderon, S., Alongi, A., Ayangeakaa, A. D., Beard, M., Best, A., Browne, J., Cahillane, C., Couder, M., deBoer, R. J., Kontos, A., Lamm, L., Li, Y. J., Long, A., Lu, W., Lyons, S., Notani, M., …Woosley, S. E. (2015). The first direct measurement of ¹²C (¹²C,n) ²³Mg at stellar energies. Physical review letters, 114(25), 251102. https://doi.org/10.1103/PhysRevLett.114.251102

Neutrons produced by the carbon fusion reaction ¹²C(¹²C,n)²³Mg play an important role in stellar nucleosynthesis. However, past studies have shown large discrepancies between experimental data and theory, leading to an uncertain cross section extrapo... Read More about The first direct measurement of ¹²C (¹²C,n) ²³Mg at stellar energies.

Nucleosynthesis simulations for the production of the p-nuclei 92Mo and 94Mo in a Supernova type II model (2015)
Journal Article
Göbel, K., Glorius, J., Koloczek, A., Pignatari, M., Reifarth, R., Schach, R., & Sonnabend, K. (2015). Nucleosynthesis simulations for the production of the p-nuclei 92Mo and 94Mo in a Supernova type II model. EPJ Web of Conferences, 93, 03006. https://doi.org/10.1051/epjconf/20159303006

We present a nucleosynthesis sensitivity study for the γ-process in a Supernova type II model within the NuGrid research platform. The simulations aimed at identifying the relevant local production and destruction rates for the p-nuclei of molybdenum... Read More about Nucleosynthesis simulations for the production of the p-nuclei 92Mo and 94Mo in a Supernova type II model.

Constraining the 12C+12C fusion cross section for astrophysics (2015)
Presentation / Conference Contribution
Bucher, B., Fang, X., Tang, X., Tan, W., Almaraz-Calderon, S., Alongi, A., Ayangeakaa, A., Beard, M., Best, A., Browne, J., Cahillane, C., Couder, M., Dahlstrom, E., Davies, P., DeBoer, R., Kontos, A., Lamm, L., Long, A., Lu, W., Lyons, S., …Wiescher, M. Constraining the 12C+12C fusion cross section for astrophysics

The 12 C+ 12 C reaction is one of the single most important nuclear reactions in astrophysics. It strongly influences late evolution of massive stars as well as the dynamics of type Ia supernovae and x-ray superbursts. An accurate estimation of the c... Read More about Constraining the 12C+12C fusion cross section for astrophysics.

Experimental neutron capture data of 58Ni from the CERN n_TOF facility (2015)
Presentation / Conference Contribution
Žugec, P., Barbagallo, M., Colonna, N., Bosnar, D., Altstadt, S., Andrzejewski, J., Audouin, L., Bécares, V., Bečvář, F., Belloni, F., Berthoumieux, E., Billowes, J., Boccone, V., Brugger, M., Calviani, M., Calviño, F., Cano-Ott, D., Carrapiço, C., Cerutti, F., Chiaveri, E., …Wright, T. Experimental neutron capture data of 58Ni from the CERN n_TOF facility

The neutron capture cross section of 58 Ni was measured at the neutron time of flight facility n-TOF at CERN, from 27 meV to 400 keV neutron energy. Special care has been taken to identify all the possible sources of background, with the so-called ne... Read More about Experimental neutron capture data of 58Ni from the CERN n_TOF facility.

Sulfur isotopic compositions of submicrometer SiC grains from the Murchison meteorite (2015)
Journal Article
Xu, Y., Zinner, E., Gallino, R., Heger, A., Pignatari, M., & Lin, Y. (2015). Sulfur isotopic compositions of submicrometer SiC grains from the Murchison meteorite. The Astrophysical journal, 799(2), 156. https://doi.org/10.1088/0004-637x/799/2/156

We report C, Si, N, S, Mg-Al, and Ca-Ti isotopic compositions of presolar silicon carbide (SiC) grains from the SiC-rich KJE size fraction (0.5-0.8 μm) of the Murchison meteorite. One thousand one hundred thirteen SiC grains were identified based on... Read More about Sulfur isotopic compositions of submicrometer SiC grains from the Murchison meteorite.

Code dependencies of pre-supernova evolution and nucleosynthesis in massive stars: Evolution to the end of core helium burning (2015)
Journal Article
Jones, S., Hirschi, R., Pignatari, M., Heger, A., Georgy, C., Nishimura, N., Fryer, C., & Herwig, F. (2015). Code dependencies of pre-supernova evolution and nucleosynthesis in massive stars: Evolution to the end of core helium burning. Monthly notices of the Royal Astronomical Society, 447(4), 3115-3129. https://doi.org/10.1093/mnras/stu2657

Massive stars are key sources of radiative, kinetic and chemical feedback in the Universe. Grids of massive star models computed by different groups each using their own codes, input physics choices and numerical approximations, however, lead to inco... Read More about Code dependencies of pre-supernova evolution and nucleosynthesis in massive stars: Evolution to the end of core helium burning.