Astronomy and Astrophysics – Astronomy
Scientific paper
Feb 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010head...11.3213b&link_type=abstract
American Astronomical Society, HEAD meeting #11, #32.13; Bulletin of the American Astronomical Society, Vol. 41, p.705
Astronomy and Astrophysics
Astronomy
Scientific paper
It has been shown that a mixture of the outflow from massive stars ( 20%) in OB associations within superbubbles with ordinary interstellar material ( 80%) yields isotopic abundances that are consistent with measurements of galactic cosmic rays with charge (Z) ≤ 28 made by the Cosmic Ray Isotope Spectrometer (CRIS) instrument on the NASA ACE satellite. Recent measurements of Ultra-Heavy (UH) (Z ≥ 30) cosmic-ray elemental abundances by the balloon-borne TIGER experiment are also consistent with this emerging model of the OB association origin of galactic cosmic rays. The TIGER data show that refractory elements (those residing in dust grains in the ISM) are enhanced over volatile elements (those residing in gas in the ISM) by about a factor of 4, and that the abundances of both refractory and volatile elements have a mass dependence. We present here measurements of the elemental abundances of the very rare UH nuclei Zn, Ga, Ge, and Se made with the ACE-CRIS instrument. We have collected a total of 450 nuclei with Z ≥ 30 and energies in the range of 150 to 600 MeV/nucleon. Measured abundances relative to Nickel will be presented and compared with those expected if OB associations are the source of most galactic cosmic rays. Our measurements will also be compared with results from the TIGER and HEAO-3 experiments. Both the CRIS and TIGER results show an excess of Ga which is consistent with an enhanced s-process production in massive stars.
This research was supported by NASA under Grant NAG5-12929
Binns Walter
Christian Eric
Cummings Alan
de Nolfo Georgia
Israel Martin
No associations
LandOfFree
Evidence for the OB Association Origin of Galactic Cosmic Rays does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Evidence for the OB Association Origin of Galactic Cosmic Rays, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evidence for the OB Association Origin of Galactic Cosmic Rays will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1093835