Zobrazeno 1 - 10
of 55
pro vyhledávání: '"J. C. Higdon"'
Autor:
Richard E. Lingenfelter, J. C. Higdon
Publikováno v:
Space Science Reviews. 130:465-473
The differences between the composition of Galactic cosmic rays and that of the interstellar medium are manifold, and they contain a wealth of information about the varying processes that created them. These differences reveal much about the initial
Autor:
J. C. Higdon, Richard E. Lingenfelter
Publikováno v:
The Astrophysical Journal. 660:330-335
Most of the galactic core-collapse supernovae occur in OB associations that produce superbubbles, and thus, the bulk of the cosmic rays are accelerated in the cores of such superbubbles by the shock waves from these supernovae. Here we show that the
Publikováno v:
New Astronomy Reviews. 50:477-480
From recent models of 26 Al synthesis in core-collapse (Type II and Ib/c) supernovae and Wolf-Rayet stars, we have calculated the expected 1.809 MeV line fluxes from the decay of 26 Al, produced in nearby OB associations. We find that 26 Al synthesis
Autor:
J. C. Higdon, Richard E. Lingenfelter
Publikováno v:
The Astrophysical Journal. 628:738-749
We have considered the effects of both the spatial and temporal clustering of OB stars and their subsequent core-collapse supernovae on their generation of superbubbles and their resultant role as the primary source of cosmic rays. Employing a wide r
Publikováno v:
The Astrophysical Journal. 611:L29-L32
The origin of the long-lived radioactive 26Al, which has been observed in the Galactic interstellar medium from its 1.809 MeV decay gamma-ray line emission, has been a persistent problem for over twenty years. Wolf-Rayet (WR) winds were thought to be
Publikováno v:
The Astrophysical Journal. 591:228-237
The abundances of the actinide elements in the cosmic rays can provide critical constraints on the major sites of their acceleration. Using recent calculations of the r-process yields in core collapse supernovae, we have determined the actinide abund
Autor:
J. C. Higdon, Richard E. Lingenfelter
Publikováno v:
The Astrophysical Journal. 590:822-832
We investigate a superbubble origin for the well-known anomalous 22Ne/20Ne ratio found (Binns and coworkers) for the sources of cosmic rays, which is 5 times the solar wind value. We calculate self-consistently the neon isotopes synthesized by massiv
Autor:
Richard E. Lingenfelter, J. C. Higdon
Publikováno v:
The Astrophysical Journal. 582:330-341
We have developed a source model for calculating the age and path length distributions of cosmic rays reaching the solar system as the summation of the diffusive contributions of a myriad of spatially and temporally discrete sources. This new model e
Publikováno v:
The Astrophysical Journal. 550:397-409
Soft gamma-ray repeaters (SGRs) and anomalous x-ray pulsars (AXPs) are young and radio-quiet x-ray pulsars which have been rapidly spun-down to slow spin periods clustered in the range 5-12 s. Most of these unusual pulsars also appear to be associate
Publikováno v:
The Sciences. 39:24-29