The chemical composition of the young, Inter-Cloud population

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

48

Stars: Abundances, Stars: Atmospheres, Stars: Early-Type, Galaxies: Magellanic Clouds

Scientific paper

High-resolution AAT spectroscopy and lower resolution spectrophotometry are presented for three early B-type stars that are members of the young, Inter-Cloud population between the Magellanic Clouds. These spectra have been analyzed using LTE model-atmosphere techniques, to derive the stellar atmospheric parameters and photospheric chemical compositions. The latter should reflect that of the present-day interstellar medium (ISM) within the Inter-Cloud Region (ICR). From a differential analysis, the three ICR stars appear to have a mean metal abundance of ~ 1.1 dex lower than their Population i Galactic analogues, and 0.5 dex lower than the SMC star (AV 304). Hence, the ICR gas does not reflect the present-day composition of either the SMC (or LMC) ISM. Age (and distance) estimates were obtained using the theoretical isochrones of Bertelli et al. (\cite{ber94}); these imply that the young, Inter-Cloud population has an age dispersion of at least 10-40 Myr, and provide evidence for a distance gradient across the ICR. We discuss our results within the context of recent numerical simulations of the gravitational interactions between the Galaxy-LMC-SMC, that predict that the ICR was tidally disrupted from the SMC some 200 Myr ago. If the SMC was chemically homogeneous, a comparison of the ICR abundance determinations with the SMC age-metallicity relationship would then imply that the formation of the ICR must have occurred ~ 8.5 Gyr ago. Alternatively and more plausible, we postulate that the ICR gas formed from a mixture of SMC gas and an unenriched component. This is consistent with model-predictions that both a halo and disc component should have contributed to the material within the ICR during the tidal disruption.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The chemical composition of the young, Inter-Cloud population 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 The chemical composition of the young, Inter-Cloud population, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The chemical composition of the young, Inter-Cloud population will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1454078

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.