Karl-Ludwig Kratz

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We use the classical r-process model to explore the implications of the recently reported first observation of U in the extremely metal-poor, r-process element–enriched halo star CS 31082-001 for U and Th cosmochronometry. Using updated nuclear physics input and performing a new, conservative, analysis of the remaining uncertainties in the classical(More)
The Fast Micromethod is a novel quick and convenient microplate assay for determination of DNA single-strand breaks. This method measures the rate of unwinding of cellular DNA upon exposure to alkaline conditions using a fluorescent dye which preferentially binds to double-stranded DNA. Here we applied this method to determine the levels of DNA(More)
We have combined new high-resolution spectra obtained with the Hubble Space Telescope (HST) and ground-based facilities to make a comprehensive new abundance analysis of the metal-poor, halo star BD +17 3248. We have detected the third r-process peak elements osmium, platinum, and (for the first time in a metal-poor star) gold, elements whose abundances can(More)
High-resolution spectra obtained with three ground-based facilities and the Hubble Space Telescope (HST) have been combined to produce a new abundance analysis of CS 22892-052, an extremely metal-poor giant with large relative enhancements of neutron capture elements. A revised model stellar atmosphere has been derived with the aid of a large number of Fe(More)
The focus of the present review is the production of the heaviest elements in nature via the r-process. A correct understanding and modeling requires the knowledge of nuclear properties far from stability and a detailed prescription of the astrophysical environment. Experiments at CERN/ISOLDE have played a pioneering role in exploring the characteristics of(More)
We examine the Pb and Th abundances in 27 metal-poor stars (−3.1 < [Fe/H] < −1.4) whose very heavy metal (Z > 56) enrichment was produced only by the rapid (r-) nucleosynthesis process. New abundances are derived from HST/STIS, Keck/HIRES, and VLT/UVES spectra and combined with other measurements from the literature to form a more complete picture of(More)
Abundances of heavier elements (barium and beyond) in many neutron-capture-elementYrich halo stars accurately replicate the solar system r-process pattern. However, abundances of lighter neutron-capture elements in these stars are not consistent with the solar system pattern. These comparisons suggest contributions from two distinct types of r-process(More)
Karl-Ludwig Kratz Universität Mainz Email: klkratz@uni-mainz.de An interesting question in nuclear astrophysics is the fate of post X-ray burst matter. Once an accreting neutron star has undergone thermonuclear runaway, the ashes of the burst are forced down into the crust of the neutron star. With increasing density a volume element of matter undergoes a(More)
Jorge Pereira, Ana Becerril, Thom Elliot, Alfredo Estrade, Daniel Galaviz, Linda Kern, G. Lorusso, Paul Mantica, Milan Matos, Fernando Montes, Hendrik Schatz 1) National Superconducting Cyclotron Laboratory (NSCL), 2) Joint Institute of Nuclear Astrophysics (JINA), 3) Department of Physics and Astronomy, 4) Department of Chemistry Michigan State University(More)
Department of Astronomy and McDonald Observatory, University of Texas, Austin, TX 78712; chris@verdi.as.utexas.edu Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019; cowan@mail.nhn.ou.edu Department of Physics, University of Wisconsin, Madison, WI 53706; jelawler@facstaff.wisc.edu Present address: Department of Astronomy,(More)