Evidence for Newly Synthesized Lithium in Interstellar Space
| dc.creator | Knauth, David C. | |
| dc.creator | Federman, Steven R. | |
| dc.creator | Lambert, David L. | |
| dc.creator | Crane, Phillipe | |
| dc.date | 2000-04-21 | |
| dc.date.accessioned | 2026-07-07T01:53:15Z | |
| dc.date.available | 2026-07-07T01:53:15Z | |
| dc.description | As a part of a study on the variation in the 7Li/6Li ratio, high signal to noise, high resolution spectroscopy of Li I (6708 Angstroms) and K I (4044 Angstroms) were obtained toward zeta and o Per. The lithium isotope shift is approximately the same as its fine structure splitting (0.158 Angstroms), resulting in a blend of the 7Li and 6Li lines. Use of the K I line as a velocity template allowed a straightforward determination of the lithium isotopic ratio. Our high resolution observations show remarkably disparate isotope ratios: 7Li/6Li = 1 0.6 +/- 2.9 toward zeta Per and 3.6 +/- 0.6 and 1.7 +/- 0.3 toward o Per. While the results toward zeta Per are consistent with the meteoritic value, the ratio toward o Per's clouds suggest recent Galactic cosmic ray spallation. This is the first clear and unambiguous evidence for an interstellar 7Li/6Li ratio that differs dramatically from the Solar System value. The low ratio indicates a higher cosmic ray flux toward o Per than toward zeta Per. A higher flux of cosmic rays toward o Per was suggested earlier in a study of OH and HD chemistry (Federman, Weber, & Lambert 1996, ApJ 463, 181). The total lithium abundances and the K/Li ratio are useful in placing the 7Li/6Li ratio into context. We obtained total lithium abundances of (12.2 +/- 2.2) x 10^(-10) toward zeta Per and (9.8 +/- 3.5) x 10^(-10) toward o Per. The columns of K I and Li I yielded K/Li ratios that revealed no discernable trend. Since a Li isotope ratio ~2 toward o Per suggests newly processed lithium, the comparable total Li abundances and K/Li ratios are unexpected. | |
| dc.description | 15 pages, 1 figure, accepted for publication in Nature | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0004315 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0004315 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/903 | |
| dc.subject | Astrophysics | |
| dc.title | Evidence for Newly Synthesized Lithium in Interstellar Space | |
| dc.type | text |