Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-04-18
Mon.Not.Roy.Astron.Soc. 360 (2005) 1373-1380
Astronomy and Astrophysics
Astrophysics
Accepted for publication in MNRAS
Scientific paper
10.1111/j.1365-2966.2005.09126.x
We use high quality echelle spectra of 24 QSOs to provide a calibrated measurement of the total amount of Lyman-alpha forest absorption (DA) over the redshift range 2.2 < z < 3.2. Our measurement of DA excludes absorption from metal lines or the Lyman-alpha lines of Lyman limit systems and damped Lyman-alpha systems. We use artificial spectra with realistic flux calibration errors to show that we are able to place continuum levels that are accurate to better than 1%. When we combine our results with our previous results between 1.6 < z < 2.2, we find that the redshift evolution of DA is well described over 1.6 < z < 3.2 as A*(1+z)^gamma, where A = 0.0062 and gamma = 2.75. We detect no significant deviations from a smooth power law evolution over the redshift range studied. We find less H I absorption than expected at z=3, implying that the UV background is about 40% higher than expected. Our data appears to be consistent with an H I ionization rate of Gamma ~ 1.4E-12 1/s.
Hollywood Susan
James Kory
Jena Tridivesh
Kirkman David
Lubin Dan
No associations
LandOfFree
The H I opacity of the intergalactic medium at redshifts 1.6 < z < 3.2 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 The H I opacity of the intergalactic medium at redshifts 1.6 < z < 3.2, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The H I opacity of the intergalactic medium at redshifts 1.6 < z < 3.2 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-138207