Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-10-15
Astrophys.J. 598 (2003) L103-L106
Astronomy and Astrophysics
Astrophysics
to be published in ApJL, 2 figures, one table
Scientific paper
10.1086/380749
Halo globular clusters pose four succinct issues that must be solved in any scenario of their formation: single-age, single metallicity stellar populations; a lower limit ([Fe/H] ~ -2.3) to their average metallicity; comprising only 1% of the stellar halo mass, and being among the oldest stars in our Galaxy. New spectra are presented of Galactic stars and integrated spectra of Galactic globular clusters which extend to 3250 angstroms. These spectra show show that the most metal-poor and among the best-studied Galactic globular clusters show strong NH3360 absorption, even though their spectral energy distributions in the near-UV are dominated by blue horizontal branch, AF-type stars. These strong NH features must be coming from the main sequence stars in these clusters. These new data are combined with existing data on the wide range of carbon and nitrogen abundance in very metal-poor ([Fe/H] < -3.5) halo giant and dwarf stars, together with recent models of zero-metal star formation, to make a strawman scenario for globular cluster formation that can reproduce three of the above four issues, and well as related two of the three issues pertaining to nitrogen overabundance. This strawman proposal makes observational and theoretical predictions that are testable, needing specific help from the modelers to understand all of the elemental constraints on globular cluster and halo formation.
Burstein David
Li Yong
No associations
LandOfFree
Nitrogen Overabundance: Globular Cluster and Halo Formation 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 Nitrogen Overabundance: Globular Cluster and Halo Formation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nitrogen Overabundance: Globular Cluster and Halo Formation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-21474