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

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

accepted for publication in A&A

Scientific paper

10.1051/0004-6361:20053910

We 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.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Kinematics and star formation activity in the z=2.03954 damped Lyman-alpha system towards PKS 0458-020 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 Kinematics and star formation activity in the z=2.03954 damped Lyman-alpha system towards PKS 0458-020, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Kinematics and star formation activity in the z=2.03954 damped Lyman-alpha system towards PKS 0458-020 will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-86504

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.