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Abstract: We list and analyze H I absorption lines at redshifts 2 < z < 4 with columndensity 12 < logN HI < 19 in 40 high-resolutional FWHM = 8.0 km-s quasarspectra obtained with the Keck+HIRES. We de-blend and fit all H I lines within1,000 km-s of 86 strong H I lines whose column densities are logN HI-cm^-2> 15. Unlike most prior studies, we use not only Lya but also all visiblehigher Lyman series lines to improve the fitting accuracy. This revealscomponents near to higher column density systems that can not be seen in Lya.We list the Voigt profile fits to the 1339 H I components that we found. Weexamined physical properties of H I lines after separating them into severalsub-samples according to their velocity separation from the quasars, theirredshift, column density and the S-N ratio of the spectrum. We found twointeresting trends for lines with 12 < logN HI < 15 which are within 200-1000km-s of systems with logN HI > 15. First, their column density distributionbecomes steeper, meaning relatively fewer high column density lines, at z <2.9. Second, their column density distribution also becomes steeper and theirline width becomes broader by about 2-3 km-s when they are within 5,000 km-s oftheir quasar.

Autor: T. Misawa, D. Tytler, M. Iye, D. Kirkman, N. Suzuki, D. Lubin, N. Kashikawa

Fuente: https://arxiv.org/

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