Abundances and Evolution of Lithium in the Galactic Halo and Disk

Details Abundances and Evolution of Lithium in the Galactic Halo and Disk Abundances and Evolution of Lithium in the Galactic Halo and Disk

2000-10-20

arxiv.org/abs/astro-ph/0010411v1

Astronomy and Astrophysics

Astrophysics

41 pages including 7 figures 2001, ApJ, 548, xxx (20 February)

Scientific paper

10.1086/319048

We have measured the Li abundance of 18 stars with -2 <~ [Fe/H] ~< -1 and 6000 K <~ Teff <~ 6400 K, a parameter range that was poorly represented in previous studies. We examine the Galactic chemical evolution (GCE) of this element, combining these data with previous samples of turnoff stars over the full range of halo metallicities. We find that A(Li) increases from a level of \~2.10 at [Fe/H] = -3.5, to ~2.40 at [Fe/H] = -1.0, where A(Li) = log_10 (n(Li)/n(H)) + 12.00. We compare the observations with several GCE calculations, including existing one-zone models, and a new model developed in the framework of inhomogeneous evolution of the Galactic halo. We show that Li evolved at a constant rate relative to iron throughout the halo and old-disk epochs, but that during the formation of young-disk stars, the production of Li relative to iron increased significantly. These observations can be understood in the context of models in which post-primordial Li evolution during the halo and old-disk epochs is dominated by Galactic cosmic ray fusion and spallation reactions, with some contribution from the $\nu$-process in supernovae. The onset of more efficient Li production (relative to iron) in the young disk coincides with the appearance of Li from novae and AGB stars. The major challenge facing the models is to reconcile the mild evolution of Li during the halo and old-disk phases with the more efficient production (relative to iron) at [Fe/H] > -0.5. We speculate that cool-bottom processing (production) of Li in low-mass stars may provide an important late-appearing source of Li, without attendant Fe production, that might explain the Li production in the young disk.

Affiliated with

Also associated with

No associations

Rating

Abundances and Evolution of Lithium in the Galactic Halo and Disk 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 Abundances and Evolution of Lithium in the Galactic Halo and Disk, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Abundances and Evolution of Lithium in the Galactic Halo and Disk will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-666788