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Thermonuclear model for x-ray transients

Description: The thermonuclear evolution of a 1.41 M sub solar neutron star accreting both solar and metal-deficient mixtures of hydrogen, helium, and heavy elements at rates ranging from about 10/sup -11/ to 10/sup -10/ M sub solar per year is examined using a one-dimensional numerical model. The metal deficient compositions may result either from placement of the neutron star in a binary system with a Population II red giant or from gravitational settling of heavy ions in the accreted material. For such a… more
Date: January 1, 1982
Creator: Wallace, R. K.; Woosley, S. E. & Weaver, T. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Neutron capture cross sections of /sup 178/,/sup 179/,/sup 180/Hf and the origin of nature's rarest stable isotope /sup 180/Ta

Description: The neutron capture cross sections of /sup 178/,/sup 179/,/sup 180/Hf were measured in the energy range 2.6 keV to 2 MeV. The average capture cross sections were derived and fitted in terms of strength functions. Resonance parameters for the observed resonances below 10 keV were determined by shape analysis. Maxwellian-averaged capture cross sections were computed for thermal energies with kT between 5 and 100 keV. The cross sections for kT = 30 keV were used to determine the population probabi… more
Date: January 1, 1982
Creator: Beer, H. & Macklin, R.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Thermonuclear model for high energy transients

Description: The thermonuclear model for x- and ..gamma..-ray bursts is discussed. Different regimes of nuclear burning are reviewed, each appropriate to a given range of (steady state) accretion rate. Accretion rates in the range 10/sup -14/ to 10/sup -8/ Msub solar y/sup -1/ all appear capable of producing x-ray transients of various durations and intervals. Modifications introduced by radiatively driven mass loss, the thermal inertia of the envelope, different burning mechanisms, and two-dimensional cons… more
Date: January 1, 1982
Creator: Woosley, S.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Gamma bursts

Description: The origin of cosmic gamma bursts is discussed. Radiation thermalization in magnetic fields, spectral mechanisms, and charge separation and photon heating are discussed. (GHT)
Date: December 9, 1982
Creator: Colgate, S.A. & Petschek, A.G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Application of Two-time Methods in Stellar Pulsations

Description: The method of two-time expansions is extended to include the effects of the outer, non-adiabatic layers in stellar pulsation. The evolution of pulsating stellar models can be examined, including the approach to limit cycle behavior. The method is demonstrated by a calculation of the eigenvectors for a ..beta.. Cepheid model. It is argued that the method is promising as a practical tool for treating the approach to limiting oscillations, as well as resonant and multimode behavior.
Date: July 28, 1982
Creator: Pesnell, W. Dean; Regev, Oded & Buchler, J. Robert
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Stability of full-amplitude solutions for RR Lyrae variables

Description: Since the discovery of numerous double-mode RR Lyrae variables in the globular cluster M15 by Cox, Hodson, and Clancy (1981a and 1983, CHC), double-mode behavior in these Population II variables has made it possible to theoretically determine their masses, composition, and maybe even their evolution direction. The most unusual characteristic of these new double-mode pulsators is that they are found in a narrow range of first overtone periods (P/sub 1/=0./sup d/38-0./sup d/43) and period ratios … more
Date: July 30, 1982
Creator: Hodson, Stephen W. & Cox, Arthur N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

1D thermonuclear model for x-ray transients

Description: The thermonuclear evolution of a 1.41 M solar mass neutron star, with a radius of 14.3 km, accreting various mixtures of hydrogen, helium, and heavy elements at rates of 10/sup -11/ to 10/sup -10/ M solar mass/yr is examined, in conjunction with S.E. Woosley and T.A. Weaver, using a one-dimensional numerical model. We have ignored any effects due to general relativity or magnetic fields. Two cases shall be discussed. In both models, the accretion rate is such that the hydrogen shell burns to he… more
Date: January 1, 1982
Creator: Wallace, R. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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