Nitrogen Abundances in High-z DLAs

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dc.creatorMolaro, P.
dc.creatorCenturion, M.
dc.creatorD'Odorico, V.
dc.creatorPeroux, C.
dc.date2003-07-09
dc.date.accessioned2026-07-07T02:08:57Z
dc.date.available2026-07-07T02:08:57Z
dc.descriptionDetermination of chemical abundances for elements produced mainly by Type I SNae and intermediate mass stars in high redshift DLAs probes the early chemical build-up on time-scales comparable with their production. Nitrogen shows a peculiar behaviour never detected before in any other class of objects. For [N/H] < -3 there is a plateau with [N/Si]= -1.45(\pm 0.05). We interpret this as empirical evidence for primary N production by massive stars in young systems where AGB stars have not yet had time to make their contribution. The plateau provides the observational integrated yields for N production by massive stars which are theoretically rather uncertain. High N/Si and solar [alpha/iron-peak] ratios are observed at high redshift and place at an earlier epoch the onset of star formation. On the other hand, low N/Si, i.e. young objects, are observed also at relatively low redshifts. These evidences suggest that DLAs started to be formed at a very early epoch but their formation has been extended up to later times.
dc.description8 pages, 7 figures, proceedings of the conference "Origin and Evolution of the Elements" 2003 Pasadena, Carnegie Observatories
dc.identifierhttps://arxiv.org/abs/astro-ph/0307173
dc.identifierhttp://arxiv.org/abs/astro-ph/0307173
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/6260
dc.subjectAstrophysics
dc.titleNitrogen Abundances in High-z DLAs
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