Temperature fluctuations in the intergalactic medium

Details Temperature fluctuations in the intergalactic medium Temperature fluctuations in the intergalactic medium

2001-10-29

arxiv.org/abs/astro-ph/0110600v2

Mon.Not.Roy.Astron.Soc. 332 (2002) 367-382

Astronomy and Astrophysics

Astrophysics

17 pages, minor changes, MNRAS published version

Scientific paper

10.1046/j.1365-8711.2002.05316.x

The temperature of the low-density intergalactic medium is set by the balance between adiabatic cooling resulting from the expansion of the universe, and photo-heating by the UV-background. We have analysed the Lyman-alpha forest of eleven high-resolution quasar spectra using wavelets, and find strong evidence of a marked jump in the temperature at the mean density, T_0, of 60 per cent around a redshift z=3.3, which we attribute to reionization of HeliumII. The jump can be seen in all three of our spectra that straddle redshift 3.3, at a significance of 99 per cent. Below z=3.1, our results are consistent with a smooth cooling down of the universe, as expected when adiabatic expansion dominates over photo-heating by a UV-background from QSOs and galaxies. We find no evidence of thermal fluctuations on scales greater than 5000 km/s larger than 50 per cent, which could be detected by our method, suggesting that the IGM follows a reasonably well-defined temperature-density relation. We demonstrate that the mean wavelet amplitude scales inversely with T_0 and calibrate the relation with hydrodynamical simulations. We find T_0= 12000K at z>3.6. Such high temperature suggest that Hydrogen reionization occured relatively recent.

Affiliated with

Also associated with

No associations

Rating

Temperature fluctuations in the intergalactic medium 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 Temperature fluctuations in the intergalactic medium, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Temperature fluctuations in the intergalactic medium will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-72709