Friday, November 4, 2005

Dr. Richard Rothschild

UCSD

"Al-26 Production in the Galaxy, especially in OB Associations"

2:00 pm in room P-148

Abstract: While theories of nucleosynthesis have made the origin of the elements quite clear, the details are proving quite troublesome. Of the long lived radionuclides that one has a hope of observing, Al-26 is the dominant isotope. I will present results from observations on the content of Al-26 in the Galaxy and in nearby young OB associations, that one would expect to be prolific sources of Al-26. I will present the various proposed sources of Al-26, and show that an additional source is needed. We have calculated the expected flux produced in nearby OB associations, and we find that synthesis solely in Type II supernovae and in Wolf Rayet stars cannot account for the flux. We suggest a stochastic component to the observed flux resulting from binary SNIb/c events can fill the bill.