Probing the Chemical Content of the Universe with sub-DLA systems

Details Probing the Chemical Content of the Universe with sub-DLA systems Probing the Chemical Content of the Universe with sub-DLA systems

Feb 2008

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008noao.prop..488m&link_type=abstract

NOAO Proposal ID #2008A-0488

Computer Science

Scientific paper

Damped Lyman-(alpha) (DLA) systems have historically been used as the probes of the neutral gas content of the Universe, however these systems appear to show low metallicity and little evolution with time. Including contributions from DLAs, Lyman-(alpha) forest clouds, and sub- mm galaxies, we can account for only ~30-40% of the expected amount of metals, contradicting the predictions of various chemical evolution models of galaxies, the ``missing metals problem''. With recent observations, we have shown that the lesser observed sub-DLA systems appear to have a higher mean metallicity than their DLA counterparts, and may contribute quite significantly to the overall metallicity of the universe. Sub-DLAs are particularly under-sampled at z < 0.7, and at 1.5 < z < 2.5 where the DLA metallicity is well constrained to be ~10% solar by a robust sample. As sub-DLAs are far more numerous than DLAs, a comparatively larger sample these systems is needed to determine their contribution to the N_H I- weighted mean metallicity, which is dominated by the higher N_H I DLA systems in the current sample. We can also better determine N_H I for the systems at z ⪆ 1.8 with the excellent blue sensitivity of the MIKE spectrograph. We request 2 nights of observations with the Magellan II telescope and the MIKE spectrograph to investigate 10 sub-DLAs at 1.5 < z < 2.5 and 1 night of observations with Keck-I and HIRESb to observe 4 sub-DLAs at z < 0.7.

Affiliated with

Also associated with

No associations

Rating

Probing the Chemical Content of the Universe with sub-DLA systems 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 Probing the Chemical Content of the Universe with sub-DLA systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Probing the Chemical Content of the Universe with sub-DLA systems will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1528821