A Unified Fitting of HI and HeII LyαTransmitted Flux of QSO HE2347 with LCDM Hydrodynamic Simulations

Details A Unified Fitting of HI and HeII LyαTransmitted Flux of QSO HE2347 with LCDM Hydrodynamic Simulations A Unified Fitting of HI and HeII LyαTransmitted Flux of QSO HE2347 with LCDM Hydrodynamic Simulations

2006-03-22

arxiv.org/abs/astro-ph/0603598v1

Astrophys.J. 645 (2006) 861-867

Astronomy and Astrophysics

Astrophysics

21 pages, 7 figs, ApJ in press

Scientific paper

10.1086/504419

Using cosmological hydrodynamic simulations of the LCDM model, we present a comparison between the simulation sample and real data sample of HI and HeII Ly\alpha transmitted flux in the absorption spectra of the QSO HE2347-4342. The LCDM model is successful in simultaneously explaining the statistical features of both HI and HeII Ly\alpha transmitted flux. It includes: 1.) the power spectra of the transmitted flux of HI and HeII can be well fitted on all scales > 0.28h^{-1} Mpc for H, and > 1.1h^{-1} Mpc for He; 2.) the Doppler parameters of absorption features of HeII and HI are found to be turbulent-broadening; 3.) the ratio of HeII to HI optical depths are substantially scattered, due to the significant effect of noise. A large part of the \eta-scatter is due to the noise in the HeII flux. However, the real data contain more low-\eta events than simulation sample. This discrepancy may indicate that the mechanism leading extra fluctuations upon the simulation data, such as a fluctuating UV radiation background, is needed. Yet, models of these extra fluctuations should satisfy the constraints: 1.) if the fluctuations are Gaussian, they should be limited by the power spectra of observed HI and HeII flux; 2.) if the fluctuations are non-Gaussian, they should be limited by the observed non-Gaussian features of the HI and HeII flux.

Affiliated with

Also associated with

No associations

Rating

A Unified Fitting of HI and HeII LyαTransmitted Flux of QSO HE2347 with LCDM Hydrodynamic Simulations 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 A Unified Fitting of HI and HeII LyαTransmitted Flux of QSO HE2347 with LCDM Hydrodynamic Simulations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Unified Fitting of HI and HeII LyαTransmitted Flux of QSO HE2347 with LCDM Hydrodynamic Simulations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-547887