Article
Astronomy & Astrophysics
Chris Nagele, Hideyuki Umeda, Koh Takahashi
Summary: The assembly of supermassive black holes is challenging due to the presence of quasars at high redshift and the lack of observations of intermediate mass black holes. Direct collapse triggered by the merger of gas-rich galaxies is a plausible scenario for creating supermassive black holes. We investigate the behavior of metal-enriched supermassive stars collapsing due to relativistic radial instability during hydrogen burning. These stars contain both hydrogen and metals and may explode through nuclear reactions, which we simulate through stellar evolution and general relativistic hydrodynamical simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jason L. Sanders, Vasily Belokurov, Kai T. F. Man
Summary: This study confirms the significant contribution of sub-Chandrasekhar mass Type Ia supernovae to the chemical enrichment of the Gaia Sausage galaxy, with yields needing to be metallicity dependent. The research also suggests that in metal-poor systems, sub-Chandrasekhar mass channels may be the dominant contribution to Type Ia supernovae.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
O. Rodriguez, N. Meza, J. Pineda-Garcia, M. Ramirez
Summary: In this study, the Ni-56 mass estimates for 110 normal Type II supernovae were presented based on their luminosity in the radioactive tail. The Ni-56 mass distribution of the sample ranged from 0.005 to 0.177 solar masses, with an average of 0.037 solar masses. By combining these results with iron isotope ratios, a mean iron yield of 0.040 solar masses for normal Type II supernovae was calculated. The empirical relation between Ni-56 mass and steepness parameter was found to be poorly suited for measuring Ni-56 mass of normal Type II supernovae. Instead, a correlation between Ni-56 mass, steepness parameter, and absolute magnitude at 50 days since explosion was presented to measure Ni-56 masses with a precision around 30 percent.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Thomas Lawson, Marco Pignatari, Richard J. Stancliffe, Jacqueline den Hartogh, Sam Jones, Chris L. Fryer, Brad K. Gibson, Maria Lugaro
Summary: This study examines the impact of core-collapse supernovae on the production of short-lived radioactive isotopes and finds that explosion energy and remnant mass play crucial roles in determining the final yields of these isotopes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Jordan Schofield, Marco Pignatari, Richard J. Stancliffe, Peter Hoppe
Summary: In this study, isotopic abundances of C, N, Al, Si, and Ti measured in presolar grains were compared with predictions from 21 CCSN models. The research found that high energy models favor the formation of a C/Si zone enriched in C-12, Si-28, and Ti-44.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
P. Eitner, M. Bergemann, A. J. Ruiter, O. Avril, I. R. Seitenzahl, M. R. Gent, B. Cote
Summary: By studying the abundances of nickel in Galactic stars, we have constrained the role of different Type Ia supernova channels in the chemical enrichment of the Galaxy. We found that non-local thermodynamic equilibrium (NLTE) effects have a negligible impact on the observed nickel abundances in the stars. In LTE, most stars have scaled solar nickel abundances, while in NLTE, we found a mild anti-correlation between nickel and metallicity.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Liliya Imasheva, Hans-Thomas Janka, Achim Weiss
Summary: Thermal bombs are widely used to trigger core-collapse supernova explosions. Recent studies have shown that if the explosions are slow, the production of Ni-56, Ni-57, and Ti-44 will be significantly lower than observational estimates. This suggests that rapid explosions are required to match observed abundances. However, our research demonstrates that these conclusions are a result of ignoring the initial collapse of the stellar core in the thermal-bomb modeling. When the initial collapse is included, the anticorrelation between Ni-56 yield and energy-injection time-scale disappears, and even more Ni-56 can be produced by slower explosions. We also propose the most appropriate setup for thermal bombs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Shin-ichiro Fujimoto, Hiroki Nagakura
Summary: The study shows that asymmetric neutrino emissions affect the explosive nucleosynthesis in core-collapse supernovae, leading to significant variations in abundances of elements heavier than nickel in the ejecta. Different degrees of asymmetry in neutrino emissions also impact the average abundances of lighter and heavier elements in the ejecta, with potential evidence of these effects being observable through spectroscopic X-ray observations in the future.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Shin-ichiro Fujimoto, Hiroki Nagakura
Summary: In this study, we investigate the impact of fast neutrino-flavour conversion (FFC) on explosive nucleosynthesis in core-collapse supernovae by including its effects in nucleosynthetic computations. It is found that FFC has little effect on the ejecta compositions for elements lighter than Co, but influences the heavier elements. The role of FFC varies depending on the degree of asymmetric neutrino emission and flavour mixing. Our results suggest that FFC facilitates the production of neutron-rich ejecta in most cases, but may make the ejecta proton-rich if anti-neutrino conversion is more vigorous than neutrino conversion, which can be quantified by simple diagnostics.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
S. Chanlaridis, J. Antoniadis, D. R. Aguilera-Dena, G. Graefener, N. Langer, N. Stergioulas
Summary: This article discusses the process of neutron star formation or explosion as supernovae for stars with masses between 7 and 11 times that of the Sun. The study finds that helium star models with masses between 1.8 and 2.7 times that of the Sun are likely to evolve into (C)ONe cores and initiate explosive burning. The amount of residual carbon plays a critical role in determining the final outcome.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Moritz M. M. Pleintinger, Roland Diehl, Thomas Siegert, Jochen Greiner, Martin G. H. Krause
Summary: We studied the emission of radioactive Al-26 using all available gamma-ray data, including single and double events collected from 2003 to 2020 on the INTEGRAL telescope. By improving the spectral response and background evaluation, we enhanced the exposure of the Galactic Al-26 emission. Through maximum likelihood fits of simulated and model-built sky distributions to SPI spectra for single and double detector hits, we determined the intensity and spatial distribution of the Galactic Al-26 emission.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Marta Molero, Laura Magrini, Francesca Matteucci, Donatella Romano, Marco Palla, Gabriele Cescutti, Carlos Viscasillas Vazquez, Emanuele Spitoni
Summary: We investigate the origin of neutron-capture elements in the Galactic thin disc by analysing their abundance patterns and radial gradients. Our detailed two-infall chemical evolution model includes nucleosynthesis prescriptions for neutron-capture elements and considers different synthesis sources. We compare our model predictions with data from the Gaia-ESO survey and find good agreement regarding the [Eu/Fe] versus [Fe/H] diagram and the [Fe/H] gradient slope. However, the predicted [Eu/H] radial gradient slope is steeper than observed, prompting discussion on Galaxy-formation scenarios and stellar radial migration effects. We also note slight underpredictions for Mo and Nd and successful reproduction of the [Pr/Fe] versus [Fe/H] trend.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Wynn V. Jacobson-Galan, Raffaella Margutti, Charles D. Kilpatrick, John Raymond, Edo Berger, Peter K. Blanchard, Alexey Bobrick, Ryan J. Foley, Sebastian Gomez, Griffin Hosseinzadeh, Danny Milisavljevic, Hagai Perets, Giacomo Terreran, Yossef Zenati
Summary: The late-time bolometric light curve of SN 2019ehk can be predominantly described by the radioactive decay of Co-56, with no statistical evidence for incomplete positron trapping in the supernova ejecta. Although the exact masses of other radioactive isotopes synthesized in SN 2019ehk cannot be constrained by our observations, we estimate a mass ratio limit of M(Co-57)/M(Co-56) <= 0.030. This limit is consistent with the explosive nucleosynthesis produced in the merger of low-mass white dwarfs, a favored progenitor scenario in early-time studies of SN 2019ehk.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
L. Roberti, M. Pignatari, A. Psaltis, A. Sieverding, P. Mohr, Zs. Fulop, M. Lugaro
Summary: The gamma-process nucleosynthesis in core-collapse supernovae is widely accepted, but discrepancies between theory and observations still exist. The average yields of gamma-process nucleosynthesis from massive stars are insufficient and the yields of Mo and Ru isotopes are significantly lower. The study investigates different core-collapse supernova models and finds significant differences in the gamma-process yields and isotopic ratios. The contribution of C-O shell mergers in the supernova progenitors to the gamma-process is also investigated.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Umberto Battino, Claudia Lederer-Woods, Marco Pignatari, Benjamin Soos, Maria Lugaro, Diego Vescovi, Sergio Cristallo, Philip J. Woods, Amanda Karakas
Summary: This study re-evaluates the production of Al-26 and its impact on stellar nucleosynthesis. The new reactivities have a significant effect on both low- and high-mass stars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Thomas C. L. Trueman, Benoit Cote, Andres Yague Lopez, Jacqueline den Hartogh, Marco Pignatari, Benjamin Soos, Amanda Karakas, Maria Lugaro
Summary: Analysis of inclusions in primitive meteorites reveals the existence of short-lived radionuclides with half-lives of 0.1-100 Myr in the early solar system. This study investigates the origin of these radionuclides and their formation in the early solar system using galactic chemical evolution modeling.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
K. Farouqi, F-K Thielemann, S. Rosswog, K-L Kratz
Summary: In this study, the origins and abundance patterns of r-process elements in very metal-poor halo stars were investigated using statistical methods. It was found that there are at least three active r-process nucleosynthesis sites, some of which are associated with iron co-production and others are not. Further division was also observed among strong r-process sites, with some being attributed to neutron star mergers and others to black hole accretion disk outflows.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Jacqueline den Hartogh, Maria K. Peto, Thomas Lawson, Andre Sieverding, Hannah Brinkman, Marco Pignatari, Maria Lugaro
Summary: Isotope variations among solar system solid samples are well documented but their origin is still uncertain. This study suggests that chromite grains from supernova explosions could be the source of these variations, and the addition of material from helium burning can reproduce the correlation between Mg and Cr anomalies.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Somdutta Ghosh, Noah Wolfe, Carla Frohlich
Summary: In this paper, the authors investigated the impact of eight different nuclear equations of state using the PUSH method, and predicted the explosion properties and nucleosynthesis yields. The results show that the differences between the equations of state are not large enough to rule out any of them.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Umberto Battino, Marco Pignatari, Ashley Tattersall, Pavel Denissenkov, Falk Herwig
Summary: Asymptotic Giant Branch (AGB) stars play a crucial role in galactic chemical evolution by producing light elements and heavy elements via the s-process. This study discusses the progress in updating the NuGrid data set of AGB stellar models and abundance yields, focusing on computational models and nucleosynthesis.
Article
Astronomy & Astrophysics
Ian U. Roederer, John J. Cowan, Marco Pignatari, Timothy C. Beers, Elizabeth A. Den Hartog, Rana Ezzeddine, Anna Frebel, Terese T. Hansen, Erika M. Holmbeck, Matthew R. Mumpower, Vinicius M. Placco, Charli M. Sakari, Rebecca Surman, Nicole Vassh
Summary: This study presents new observational benchmarks for rapid neutron-capture process nucleosynthesis in metal-poor stars, offering an alternative to the predicted solar system r-process residual pattern. The findings suggest a potential inconsistency between the abundances of lighter and heavier r-process elements in these stars. The results also indicate the possibility of a universal abundance pattern among certain elements, spanning the first and second r-process peaks.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
T. Mishenina, M. Pignatari, T. Gorbaneva, B. Cote, A. Yague Lopez, F-K Thielemann, C. Soubiran
Summary: This paper presents new observational data for Gd, Dy, and Th in Galactic disc stars and compares them with nucleosynthesis predictions and Galactic Chemical Evolution simulations. The study confirms that Gd and Dy show similar behavior to Eu, while Th may be influenced by metallicity.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Review
Astronomy & Astrophysics
Almudena Arcones, Friedrich-Karl Thielemann
Summary: The origin of the elements we find in various substances such as oxygen, hydrogen, carbon, silicon, calcium, iron, silver, gold, rare earths, and uranium and plutonium can be traced back to astrophysical environments like the Big Bang and stellar explosions. Understanding nucleosynthesis processes, combined with nuclear physics input and environmental conditions, has been key in determining how these elements are formed. Continuous advancements in nuclear experiments, astrophysical models, and stellar evolution have deepened our understanding of this process and its impact on the evolution of galaxies.
ASTRONOMY AND ASTROPHYSICS REVIEW
(2023)
Article
Astronomy & Astrophysics
Peter Hoppe, Jan Leitner, Marco Pignatari, Sachiko Amari
Summary: We present isotope data of SiC grains from a chondrite believed to have formed in the ejecta of supernova explosions. The C, N, and Si isotopic compositions of these grains are consistent with previous studies. The presence of monoisotopic Mg-26 supports the decay of radioactive Al-26. The high Al-26/Al-27 ratios observed in this study are important for understanding the production of Al-26 in supernova models and suggest that previous measurements may have been affected by Al contamination.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Physics, Nuclear
H. Schatz, A. D. Becerril Reyes, A. Best, E. F. Brown, K. Chatziioannou, K. A. Chipps, C. M. Deibel, R. Ezzeddine, D. K. Galloway, C. J. Hansen, F. Herwig, A. P. Ji, M. Lugaro, Z. Meisel, D. Norman, J. S. Read, L. F. Roberts, A. Spyrou, I Tews, F. X. Timmes, C. Travaglio, N. Vassh, C. Abia, P. Adsley, S. Agarwal, M. Aliotta, W. Aoki, A. Arcones, A. Aryan, A. Bandyopadhyay, A. Banu, D. W. Bardayan, J. Barnes, A. Bauswein, T. C. Beers, J. Bishop, T. Boztepe, B. Cote, M. E. Caplan, A. E. Champagne, J. A. Clark, M. Couder, A. Couture, S. E. de Mink, S. Debnath, R. J. deBoer, J. den Hartogh, P. Denissenkov, V Dexheimer, I Dillmann, J. E. Escher, M. A. Famiano, R. Farmer, R. Fisher, C. Frohlich, A. Frebel, C. Fryer, G. Fuller, A. K. Ganguly, S. Ghosh, B. K. Gibson, T. Gorda, K. N. Gourgouliatos, V Graber, M. Gupta, W. C. Haxton, A. Heger, W. R. Hix, W. C. G. Ho, E. M. Holmbeck, A. A. Hood, S. Huth, G. Imbriani, R. G. Izzard, R. Jain, H. Jayatissa, Z. Johnston, T. Kajino, A. Kankainen, G. G. Kiss, A. Kwiatkowski, M. La Cognata, A. M. Laird, L. Lamia, P. Landry, E. Laplace, K. D. Launey, D. Leahy, G. Leckenby, A. Lennarz, B. Longfellow, A. E. Lovell, W. G. Lynch, S. M. Lyons, K. Maeda, E. Masha, C. Matei, J. Merc, B. Messer, F. Montes, A. Mukherjee, M. R. Mumpower, D. Neto, B. Nevins, W. G. Newton, L. Q. Nguyen, K. Nishikawa, N. Nishimura, F. M. Nunes, W-J Ong, S. D. Pain, M. A. Pajkos, M. Pignatari, R. G. Pizzone, V. M. Placco, T. Plewa, B. Pritychenko, A. Psaltis, D. Puentes, Y-Z Qian, D. Radice, D. Rapagnani, B. M. Rebeiro, R. Reifarth, A. L. Richard, N. Rijal, I. U. Roederer, J. S. Rojo, Y. Saito, A. Schwenk, M. L. Sergi, R. S. Sidhu, A. Simon, T. Sivarani, M. S. Smith, A. Spiridon, T. M. Sprouse, S. Starrfield, A. W. Steiner, F. Strieder, I Sultana, R. Surman, T. Szucs, A. Tawfik, F. Thielemann, L. Trache, R. Trappitsch, M. B. Tsang, A. Tumino, S. Upadhyayula, J. O. Valle Martinez, M. Van der Swaelmen, Carlos Viscasillas Vazquez, A. Watts, B. Wehmeyer, M. Wiescher, C. Wrede, J. Yoon, R. G. T. Zegers, M. A. Zermane, M. Zingale, E. O'Connor, A. Skuladottir
Summary: This paper summarizes the progress and status of nuclear astrophysics, explores new open questions, and highlights the scientific opportunities that have emerged. It also discusses the unique challenges and opportunities in nuclear astrophysics in terms of science, diversity, education, and interdisciplinary collaboration.
JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
M. Reichert, M. Obergaulinger, M. A. Aloy, M. Gabler, A. Arcones, F. K. Thielemann
Summary: Magnetorotational supernovae are a rare type of core-collapse supernovae that involve magnetic fields and rotation in the explosion dynamics. Post-processed nucleosynthesis of neutrino-MHD supernova models reveals three mechanisms for heavy r-process element production. The study highlights the role of magnetorotational supernovae in hypernovae, superluminous supernovae, and heavy element synthesis.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Hannah E. Brinkman, Carolyn Doherty, Marco Pignatari, Onno Pols, Maria Lugaro
Summary: In this study, the impact of binary interactions on the production of short-lived radioactive nuclei in massive stars was investigated. It was found that models with initial masses greater than or equal to 25 M (&ODOT;) can self-consistently match the abundances of Al-26 and Ca-41 in the early solar system, while models with initial primary masses greater than or equal to 35 M (&ODOT;) can also match Cl-36. Additionally, binary interactions were found to strongly impact the evolution of stars close to the supernova boundary.
ASTROPHYSICAL JOURNAL
(2023)
Article
Physics, Nuclear
Friedrich-Karl Thielemann
Summary: This contribution begins by recalling Franz Kappeler as both a person and a scientist and his contributions to neutron capture nucleosynthesis through experiments and astrophysical studies. It then expands on his research focus (the s-process) to discuss the r-process, including its mechanism, related astrophysical sites, and its role during galactic evolution.
EUROPEAN PHYSICAL JOURNAL A
(2023)
Article
Astronomy & Astrophysics
McKenzie Myers, Theo Cooper, MacKenzie Warren, Jim Kneller, Gail McLaughlin, Sherwood Richers, Evan Grohs, Carla Frohlich
Summary: The successful transition from classical neutrino transport to quantum neutrino transport simulations requires the development of methods for calculating neutrino flavor transformations. One potential approach is the use of angular moments of the neutrino field, which can be straightforwardly generalized from the classical moments based on the Boltzmann equation. The efficient implementation of neutrino transformation using quantum angular moments in the free streaming, spherically symmetric bulb model predicts the onset of collective flavor transformations with good accuracy.
Article
Astronomy & Astrophysics
Thomas M. Cross, David M. Benoit, Marco Pignatari, Brad K. Gibson
Summary: This work presents a new approach implemented in the Prometheus code to model synthetic rovibrational spectra for all molecules of astrophysical interest. The study evaluates the accuracy of this method by analyzing four diatomic molecules and shows that the simple model achieves better approximation of real spectra. The results are compared with high-resolution spectral data, revealing a decrease in modeling accuracy for rovibrational transitions away from the band origin, highlighting the need for further adaptation of the theory.
ASTROPHYSICAL JOURNAL
(2022)
