Constraining the high-redshift quasar luminosity function
File(s)
Author(s)
Finer, Jasmine Liliane Barnard
Type
Thesis
Abstract
Accretion onto supermassive black holes powers quasars so luminous that they can be observed at high redshifts. However, mass estimates of these quasars are in conflict with current theories of black hole growth during these early epochs. The root of this inconsistency lies within our theoretical understanding of black hole formation and evolution at high redshift, methods of estimating high redshift black hole masses, and the statistical approach to constraining the high redshift black hole population. This thesis focuses on the latter. We propose a correction to the completeness of the z~6 Stripe 82 survey (Jiang 2009) in the form of a shift in magnitude limit of ∆M_1450 = - 0.47. We present an updated formalism of parameter inference for the quasar luminosity function, using a 6 parameter double power law model
[Equation goes here please see PDF version]
and find maximum a posteriori estimates beta = -3.76, M*_1450=-26.5, j = 0.0849, Phi*= 3.25 x 10^-9 Mpc^-3, alpha = -1.73, k = -0.165. In comparison to previous work on the redshift $6$ quasar luminosity function (Willott 2010a), our modelling prefers a steeper fall off at the QLF's bright end, a brighter break magnitude which evolves slowly with redshift and a more gradual decrease in number density with redshift.
[Equation goes here please see PDF version]
and find maximum a posteriori estimates beta = -3.76, M*_1450=-26.5, j = 0.0849, Phi*= 3.25 x 10^-9 Mpc^-3, alpha = -1.73, k = -0.165. In comparison to previous work on the redshift $6$ quasar luminosity function (Willott 2010a), our modelling prefers a steeper fall off at the QLF's bright end, a brighter break magnitude which evolves slowly with redshift and a more gradual decrease in number density with redshift.
Version
Open Access
Date Issued
2016-09
Date Awarded
2017-02
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Mortlock, Daniel
Sponsor
Science and Technology Facilities Council (Great Britain)
Publisher Department
Physics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Master of Philosophy (MPhil)