Modification of the 21-cm power spectrum by quasars during the epoch of reionisation

Abstract

We assess the effect of a population of high-redshift quasars on the 21-cm power spectrum during the epoch of reionisation. Our approach is to implement a semi-numerical scheme to calculate the three-dimensional structure of ionised regions surrounding massive halos at high redshift. We include the ionising influence of luminous quasars by populating a simulated overdensity field with quasars using a Monte Carlo Markov Chain algorithm. We find that quasars modify both the amplitude and shape of the power spectrum at a level which is of the same order as the fractional contribution to reionisation. The modification is found both at constant redshift and at constant global neutral fraction, and arises because ionising photons produced by quasars are biased relative to the density field at a level that is higher than steller ionising photons. Our results imply that quasar ionisation will need to be included in detailed modelling of observed 21-cm power spectra.

12 pages, 7 figures, submitted to MNRAS

References in corpus (10)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Efficient Simulations of Early Structure Formation and Reionization
• Clustering of High Redshift ($z\ge 2.9$) Quasars from the Sloan Digital Sky Survey
• The Global 21 Centimeter Background from High Redshifts
• Detecting the Rise and Fall of 21 cm Fluctuations with the Murchison Widefield Array
• On using visibility correlations to probe the HI distribution from the dark ages to the present epoch I: Formalism and the expected signal
• Fast Large-Scale Reionization Simulations
• The correlation between the distribution of galaxies and 21cm emission at high redshifts
• Fossil Ionized Bubbles Around Dead Quasars During Reionization

Cited by in corpus (11)

• 21-cm cosmology
• Reionization and Cosmology with 21 cm Fluctuations
• Constraining the contribution of active galactic nuclei to reionisation
• Prospects of observing a quasar HII region during the Epoch of Reionization with redshifted 21cm
• Stars and Reionization: The Cross-Correlation of the 21cm Line and the Near Infrared Background
• Simulating the 21cm forest detectable with LOFAR and SKA in the spectra of high-z GRBs
• Investigating X-ray sources during the epoch of reionization with the 21 cm signal
• Reionization and feedback in overdense regions at high redshift
• Cornering Extended Starobinsky Inflation with CMB and SKA
• Observing the redshifted 21 cm signal around a bright QSO at $z\sim 10$
• Probing the Inflaton Potential with SKA