C.D.S. - SIMBAD4 rel 1.7 - 2020.07.05CEST09:44:43

2006A&A...449...33H - Astronomy and Astrophysics, volume 449, 33-39 (2006/4-1)

Kinematics and star formation activity in the zabs = 2.03954 damped Lyman-α system towards PKS 0458-020.


Abstract (from CDS):

We present UVES observations of the log N(HI)=21.7 damped Lyman-α system at zabs=2.03954 towards the quasar PKS 0458-020. HI Lyman-α emission is detected in the center of the damped Lyman-α absorption trough. Metallicities are derived for Mg II, SIII, P II, Cr II, Mn II, Fe II and Zn II and are found to be -1.21±0.12, -1.28±0.20, -1.54±0.11, -1.66±0.10, -2.05±0.11, -1.87±0.11, -1.22±0.10, 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-α emission up to a maximum of ∼100 and 200km/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-α emission, 1.6M/yr, is compared with that estimated from the observed C II* absorption. No molecular hydrogen is detected in our data, yielding a molecular fraction logf←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.

Abstract Copyright:

Journal keyword(s): cosmology: observations - galaxies: abundances - galaxies: quasars: absorption lines - galaxies: quasars: individual: PKS 0458-020 - galaxies: kinematics and dynamics

Simbad objects: 2

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Number of rows : 2

N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
1 4C -02.19 QSO 05 01 12.80988366 -01 59 14.2562534   19.1 18.4 19.04   ~ 517 1
2 [EYH2001] QSO J0501-0159 abs 2.039 DLA 05 01 12.8099 -01 59 14.256           ~ 29 0

    Equat.    Gal    SGal    Ecl

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