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Now showing items 1405-1424 of 24064

    • Astrometric and photometric initial mass functions from the UKIDSS Galactic Clusters Survey - II. The Alpha Persei open cluster 

      Lodieu, N.; Deacon, N. R.; Hambly, N. C.; Boudreault, S. (2012-11-11)
      We present the results of a deep (J = 19.1mag) infrared (ZYJHK) survey over the full α Per open cluster extracted from the Data Release 9 of the United Kingdom Infrared Telescope Infrared Deep Sky Survey Galactic Clusters ...

    • Astrometric and photometric initial mass functions from the UKIDSS Galactic Clusters Survey - III. Praesepe 

      Boudreault, S.; Lodieu, N.; Deacon, N. R.; Hambly, N. C. (2012-11-11)
      Over the past decades open clusters have been the subject of many studies. Such studies are crucial considering that the universality of the initial mass function is still a subject of current investigations. Praesepe is ...

    • Astronometry with the Hubble Space Telescope : trigonometric parallaxes of planetary nebula nuclei NGC 6853, NGC 7293, Abell 31 and DeHt 5 

      Benedict, G.F.; McArthur, B.E.; Napiwotzki, R.; Harrison, T.E.; Harris, H.C.; Nelan, E.; Bond, H.E.; Patterson, R.J.; Ciardullo, R. (2009)
      We present absolute parallaxes and relative proper motions for the central stars of the planetary nebulae NGC 6853 (The Dumbbell), NGC 7293 (The Helix), Abell 31, and DeHt 5. This paper details our reduction and analysis ...

    • Astronomia ex machina: a history, primer and outlook on neural networks in astronomy 

      Smith, Michael J.; Geach, James E. (2023-05-31)
      In this review, we explore the historical development and future prospects of artificial intelligence (AI) and deep learning in astronomy. We trace the evolution of connectionism in astronomy through its three waves, from ...

    • Astrophysical analysis of the measurement of (alpha,gamma) and (alpha,n) cross sections of Tm-169 

      Rauscher, T.; Kiss, G. G.; Szuecs, T.; Fueloep, Zs.; Froehlich, Carla; Gyuerky, Gy.; Halasz, Z.; Kertesz, Zs.; Somorjai, E. (2012-07-05)
      Reaction cross sections of Tm-169(alpha, gamma)Lu-173 and Tm-169(alpha, n)Lu-172 have been measured in the energy range 12.6

    • Astrophysical and nuclear physics aspects of the r-process 

      Thielemann, Friedrich-Karl; Freiburghaus, C.; Rauscher, T.; Kratz, K.L.; Pfeiffer, B.; Cowan, J.J. (World Scientific Publishing, 1998)
      The formation of elements as heavy as Th and U and beyond is due to the rapid neutron-capture process (r-process), which causes the production of highly unstable nuclei near the neutron drip-line and functions via neutron ...

    • Astrophysical conditions for an r-process in the high-entropy wind scenario of type II supernovae 

      Farouqi, K.; Freiburghaus, C.; Kratz, K. L.; Pfeiffer, B.; Rauscher, T.; Thielemann, Friedrich-Karl (2005-07-25)
      Within a full dynamical parameter study including freezeout effects, we have determined the astrophysical conditions for an r-process in the so-called "neutrino-wind" scenario of core-collapse type II supernovae (SNII). ...

    • The astrophysical r-process : A comparison of calculations following adiabatic expansion with classical calculations based on neutron densities and temperatures 

      Freiburghaus, C.; Rembges, J.F.; Rauscher, T.; Kolbe, E.; Thielemann, Friedrich-Karl; Kratz, K.L.; Pfeiffer, B.; Cowan, J.J. (1999-05-01)
      The rapid neutron-capture process (r-process) encounters unstable nuclei far from beta-stability. Therefore its observable features, like the abundances, witness (still uncertain) nuclear structure as well as the conditions ...

    • Astrophysical Rates for Explosive Nucleosynthesis : Stellar and Laboratory Rates for Exotic Nuclei 

      Rauscher, T. (2010-03-01)
      A selected overview of stellar effects and reaction mechanisms with relevance to the prediction of astrophysical reaction rates far off stability is provided.

    • Astrophysical reaction rate for the Li-8(n,gamma)Li-9 reaction 

      Kobayashi, H.; Ieki, K.; Horvath, A.; Galonsky, A.; Carlin, N.; Deak, F.; Gomi, T.; Guimaraes, V.; Higurashi, Y.; Iwata, Y.; Kiss, A.; Kolata, J.J.; Rauscher, T.; Schelin, H.; Seres, Z.; Warner, R. (2003-01)
      An attempt was made to measure the excitation function of the cross section for the Li-8(n,gamma)Li-9 reaction by performing the inverse reaction Li-9(gamma,n)Li-8, with the equivalent photons in the electric field of ...

    • Astrophysical Reaction Rates as a Challenge for Nuclear Reaction Theory 

      Rauscher, T. (American Institute of Physics (AIP), 2010)
      The relevant energy ranges for stellar nuclear reactions are introduced. Low-energy compound and direct reactions are discussed. Stellar modifications of the cross sections are presented. Implications for experiments are outlined.

    • Astrophysical reaction rates for B-10(p,alpha)Be-7 and B-11(p,alpha)Be-8 from a direct model 

      Rauscher, T.; Raimann, G. (1996-05)
      The reactions B-10(p,alpha)Be-7 and B-11(p,alpha)Be-8 are studied at thermonuclear energies using DWBA calculations. For both reactions, transitions to the ground states and first excited states are investigated. In the ...

    • Astrophysical reaction rates from statistical model calculations 

      Rauscher, T.; Thielemann, Friedrich-Karl (2000)
      Theoretical reaction rates in the temperature range 0.01 x 10(9) less than or equal to T(K) less than or equal to 10.0 x 10(9) are calculated in the statistical model (Hauser-Feshbach formalism) for targets with 10 less ...

    • Astrophysical relevance of gamma transition energies 

      Rauscher, T. (2008-09)
      The relevant gamma energy range is explicitly identified where additional gamma strength must be located to have an impact on astrophysically relevant reactions. It is shown that folding the energy dependences of the ...

    • Astrophysical S-factor for alpha-Capture of (113)In in the p-Process Energy Range 

      Yalcin, C.; Gueray, R. T.; Oezkan, N.; Kutlu, S.; Gyuerky, Gy.; Farkas, J.; Kiss, G. G.; Fueloep, Zs.; Rauscher, T.; Somorjai, E. (American Institute of Physics, 2009)
      The cross sections of (113)In(alpha, gamma)(117)Sb and (113)In(alpha,n)(116)Sb reactions have been measured using the activation method. The experiments were carried out at the ATOMKI cyclotron accelerator in the center ...

    • The astrophysical S-factor of the reaction Be-7(P,gamma)B-8 in the direct capture model 

      Krauss, H.; Grun, K.; Rauscher, T.; Oberhummer, H. (1993)
      The astrophysical S-factor for the reaction Be-7(p, gamma)B-8 up to an energy of 2 MeV (c.m.) and the capture cross section of Li-7(n, gamma)Li-8 up to 1 MeV (c.m.) are calculated using the Direct Capture model (DC). Both ...

    • Astrophysical S-factors and reaction rates of (p,n)-reactions on (117)Sn, (118)Sn, (122)Sn, and (124)Sn 

      Skakun, Ye; Rauscher, T. (EDP Sciences, 2008)
      Astrophysical S-factors and reaction rates were derived from available cross sections of (p,n)-reactions on (117)Sn, (118)Sn, (122)Sn, and (124)Sn isotopes at incident proton energies up to 9 MeV. The statistical theory ...

    • Astrophysical S-Factors and Reaction Rates of Threshold (p,n)-Reactions on (99-102)Ru 

      Skakun, Ye; Rauscher, T. (American Institute of Physics (AIP), 2010)
      Astrophysical S-factors of (p,n) reactions on (99)Ru, (100)Ru, (101)Ru, and (102)Ru were derived from the sum of experimental isomeric and ground states cross sections measured in the incident proton energy range of 5-9 ...

    • Astrophysics and nuclei far from stabilitys 

      Thielemann, F.K.; Kratz, K.L.; Pfeiffer, B.; Rauscher, T.; van Wormer, L.; Wiescher, M. (1994-03)
      We discuss unstable nuclei on the proton-rich and neutron rich side of stability and their properties of astrophysical relevance. The Coulomb barriers in charged-particle captures lead to a cycle pattern which is not ...

    • Astrophysics at n_TOF Facility at CERN 

      Tagliente, G.; Abbondanno, U.; Aerts, G.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Audouin, L.; Badurek, G.; Baumann, P.; Becvar, F.; Belloni, F.; Berthoumieux, E.; Bisterzo, S.; Calvino, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapico, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillman, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Gallino, R.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Kaeppeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Koehler, P.; Kossionides, E.; Krticka, M.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Mosconi, M.; Neves, F.; Oberhummer, H.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wendler, H.; Wiescher, M.; Wisshak, K. (IOP Publishing Ltd., 2011)
      The neutron time of flight (n_TOF) facility at CERN is a spallation neutron source with white neutron energy spectrum (from thermal to several GeV), covering the full energy range of interest for nuclear astrophysics, in ...