Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-10-12
Astronomy and Astrophysics
Astrophysics
submitted to ApJ Letters, 10 pages, added discussion of model dependence of Gamma, corrected small numerical error in Ly-beta
Scientific paper
10.1086/339723
The temporal evolution of the ionizing UV background radiation field at high redshift provides a probe of the evolution of the early star formation rate. By comparing the observed levels of absorption in the highest redshift quasar spectra to the predictions of a hydrodynamic simulation, we determine the evolution of the photoionization rate Gamma for neutral hydrogen in the intergalactic medium, over the redshift range 4.9 < z < 6.1. After accounting for sampling variance, we infer a sharp increase in Gamma from z~6.1 to z~5.8, probably implying reionization at this redshift. We find a decrease in Gamma from z~5.6 to 5.2, at 3sigma significance. This feature is a generic signature in the aftermath of reionization, entirely consistent with the cosmological reionization process being completed at z~6.1. This generic feature is a result of a significant change in the star formation rate subsequent to the cosmological reionization. There is an abrupt rise of the temperature of the intergalactic medium due to photo-heating, when it is reionized. This translates to a correspondingly sudden jump in the Jeans mass and a dramatic suppression of gas accretion onto the most abundant (sub-galactic) halos at the epochs of interest. The star formation rate suffers a temporary setback in the aftermath of reionization, resulting in a temporary decrease in the amplitude of the ionizing radiation field.
Cen Renyue
McDonald Patrick
No associations
LandOfFree
Evolution of the Ionizing Radiation Background and Star Formation in the Aftermath of Cosmological Reionization 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 Evolution of the Ionizing Radiation Background and Star Formation in the Aftermath of Cosmological Reionization, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolution of the Ionizing Radiation Background and Star Formation in the Aftermath of Cosmological Reionization will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-327610