This work explores the connection between cosmic rays and light element production in an active galaxy environment.
Cosmic rays generated in an active galactic nucleus (AGN) interact with the local, line-emitting gas and spall the light elements, Li, Be and B. Careful consideration of the propagation of cosmic rays from AGNs to Earth yields a variety of models that are consistent with the observed cosmic ray spectrum. However, by using observed upper limits for BIII $\lambda$2066A line emission from AGNs, we are able to rule out certain cosmic ray flux models. This analysis requires a detailed study of boron ionization balance under typical AGN conditions, a study that is carried out here for the first time. Models with a total cosmic ray luminosity $L\sb{CR}=10\sp{45}$ erg s$\sp{-1}$ and a diffusion coefficient in the line emission region of $D\le 10\sp{28}$ cm$\sp2$ s$\sp{-1}$, and those with $L\sb{CR}=10\sp{45}$ erg s$\sp{-1}$ and $D\le 3\times 10\sp{26}$ cm$\sp2$ s$\sp{-1}$ do not satisfy the spectroscopic constraints. However, models with lower cosmic ray luminosities or larger diffusion coefficients are acceptable.
The results of spallation in AGNs are also applied to our Galaxy, under the assumption that it has passed through an active phase. An additional source of light elements during this active phase can reproduce the B and Be abundances observed in the halo, and contribute partially to the light element abundances observed in the disk.
| Identifer | oai:union.ndltd.org:RICE/oai:scholarship.rice.edu:1911/19116 |
| Date | January 1994 |
| Creators | Crosas, Merce |
| Contributors | Weisheit, J. C. |
| Source Sets | Rice University |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | 147 p., application/pdf |
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