Kinematics and star formation activity in the z=2.03954 damped Lyman-alpha system towards PKS 0458-020

Simple item page
dc.creatorHeinmueller, Janine
dc.creatorPetitjean, Patrick
dc.creatorLedoux, Cedric
dc.creatorCaucci, Sara
dc.creatorSrianand, R.
dc.date2005-12-05
dc.date.accessioned2026-07-07T06:49:02Z
dc.date.available2026-07-07T06:49:02Z
dc.descriptionWe present UVES observations of the log N(HI)= 21.7 damped Lyman-alpha system at z=2.03954 towards the quasar PKS 0458-020. HI Lyman-alpha emission is detected in the center of the damped Lyman-alpha absorption trough. Metallicities are derived for MgII, SiII, PII, CrII, MnII, FeII and ZnII and are found to be -1.21\pm0.12, -1.28\pm0.20, -1.54\pm0.11, -1.66\pm0.10, -2.05\pm0.11, -1.87\pm0.11, -1.22\pm0.10, respectively, relative to solar. The depletion factor is therefore of the order of [Zn/Fe]=0.65. We observe metal absorption lines to be blueshifted compared to the Lyman-alpha emission up to a maximum of 100 and 200 km/s for low and high-ionization species respectively. This can be interpreted either as the consequence of rotation in a large (~7kpc) disk or as the imprint of a galactic wind. The star formation rate (SFR) derived from the Lyman-alpha emission, 1.6 solar masses/yr, is compared with that estimated from the observed CII* absorption. No molecular hydrogen is detected in our data, yielding a molecular fraction f<-6.52. This absence of H2 can be explained as the consequence of a high ambient UV flux which is one order of magnitude larger than the radiation field in the ISM of our Galaxy and originates in the observed emitting region.
dc.descriptionaccepted for publication in A&A
dc.identifierhttps://arxiv.org/abs/astro-ph/0512118
dc.identifierhttp://arxiv.org/abs/astro-ph/0512118
dc.identifierAstron.Astrophys. 449 (2006) 33-39
dc.identifierdoi:10.1051/0004-6361:20053910
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/104185
dc.subjectAstrophysics
dc.titleKinematics and star formation activity in the z=2.03954 damped Lyman-alpha system towards PKS 0458-020
dc.typetext

Files

Collections

arXiv