VoIgt profile Parameter Estimation Routine (VIPER): H I photoionization rate at z<0.5

Abstract

We have developed a parallel code called "VoIgt profile Parameter Estimation Routine (VIPER)" for automatically fitting the H I Ly-$\alpha$ forest seen in the spectra of QSOs. We obtained the H I column density distribution function (CDDF) and line width ($b$) parameter distribution for $z<0.45$ using spectra of 82 QSOs obtained using Cosmic Origins Spectrograph and VIPER. Consistency of these with the existing measurements in the literature validate our code. By comparing this CDDF with those obtained from hydrodynamical simulation, we constrain the H I photoionization rate (${\Gamma }_{\mathrm{HI}}$) at $z<0.45$ in four redshift bins. The VIPER, together with the Code for Ionization and Temperature Evolution (CITE) we have developed for GADGET-2, allows us to explore parameter space and perform ${\chi }^2$ minimization to obtain ${\Gamma }_{\mathrm{HI}}$. We notice that the $b$ parameters from the simulations are smaller than what are derived from the observations. We show the observed $b$ parameter distribution and $b$ vs $\log {\mathrm{N}}_{\mathrm{HI}}$ scatter can be reproduced in simulation by introducing sub-grid scale turbulence. However, it has very little influence on the derived ${\Gamma }_{\mathrm{HI}}$. The ${\Gamma }_{\mathrm{HI}}(z)$ obtained here, $(3.9\pm 0.1)\times 10^{-14}(1+z{)}^{4.98\pm 0.11}{\mathrm{s}}^{-1}$, is in good agreement with those derived by us using flux based statistics in the previous paper. These are consistent with the hydrogen ionizing ultra-violet (UV) background being dominated mainly by QSOs without needing any contribution from the non-standard sources of the UV photons.

arXiv comment17 pages, 10 figures

References in corpus (75)

• The cosmological simulation code GADGET-2
• The 3D power spectrum of galaxies from the SDSS
• Radiative transfer in a clumpy universe: IV. New synthesis models of the cosmic UV/X-ray background
• Information criteria for astrophysical model selection
• Cosmological SPH simulations: The entropy equation
• Enzo: An Adaptive Mesh Refinement Code for Astrophysics
• A New Calculation of the Ionizing Background Spectrum and the Effects of HeII Reionization
• Cosmological parameters from combining the Lyman-alpha forest with CMB, galaxy clustering and SN constraints
• The Baryon Census in a Multiphase Intergalactic Medium: 30% of the Baryons May Still Be Missing
• An updated analytic model for the attenuation by the intergalactic medium
• Gravitational Collapse of Small-Scale Structure as the Origin of the Lyman Alpha Forest
• The Lyman-alpha Forest in the Cold Dark Matter Model
• Recovery of the Power Spectrum of Mass Fluctuations from Observations of the Lyman-alpha Forest
• The thermal history of the intergalactic medium
• The Opacity of the Lyman Alpha Forest and Implications for Omega_{baryon} and the Ionizing Background
• The Linear Theory Power Spectrum from the Lyman-alpha Forest in the Sloan Digital Sky Survey
• The Lyman Alpha Forest from Gravitational Collapse in the CDM+Lambda Model
• The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization
• The Observed Probability Distribution Function, Power Spectrum, and Correlation Function of the Transmitted Flux in the Lyman-alpha Forest
• Precision measures of the primordial abundance of deuterium
• Detection of Extended He II Reionization in the Temperature Evolution of the Intergalactic Medium
• Model-independent insights into the nature of the Lyman-alpha forest and the distribution of matter in the universe
• New Measurements of the Ionizing Ultraviolet Background over 2 < z < 5 and Implications for Hydrogen Reionization
• Evolution of Structure in the Intergalactic Medium and the Nature of the Ly-alpha Forest
• Inferring the dark matter power spectrum from the Lyman-alpha forest in high-resolution QSO absorption spectra
• A High-Resolution Survey of Low-Redshift QSO Absorption Lines: Statistics and Physical Conditions of O VI Absorbers
• The Lyman-alpha forest opacity and the metagalactic hydrogen ionization rate at z~2-4
• Evolution of Neutral Gas at High Redshift -- Implications for the Epoch of Galaxy Formation
• An HST/COS Survey of the Low-Redshift IGM. I. Survey, Methodology, & Overall Results
• Large-scale Bias and Efficient Generation of Initial Conditions for Non-Local Primordial Non-Gaussianity
• Cosmological and astrophysical parameters from the SDSS flux power spectrum and hydrodynamical simulations of the Lyman-alpha forest
• A Measurement of the Temperature-Density Relation in the Intergalactic Medium Using a New Lyman-alpha Absorption Line Fitting Method
• A Deep HST Search for Escaping Lyman Continuum Flux at z~1.3: Evidence for an Evolving Ionizing Emissivity
• A Measurement of Small Scale Structure in the 2.2 < z < 4.2 Lyman-alpha Forest
• Constraints from the Lyman alpha forest power spectrum
• Possible evidence for an inverted temperature-density relation in the intergalactic medium from the flux distribution of the Lyman-alpha forest
• Measuring the equation of state of the intergalactic medium
• The intergalactic medium over the last 10 billion years I: Lyman alpha absorption and physical conditions
• HST-COS Observations of AGN. II. Extended Survey of Ultraviolet Composite Spectra from 159 Active Galactic Nuclei
• The Nature and Origin of Low-Redshift O VI Absorbers
• The Nature of the Warm/Hot Intergalactic Medium I. Numerical Methods, Convergence, and OVI Absorption
• The redshift evolution of escape fraction of hydrogen ionizing photons from galaxies
• Measuring the Sources of the Intergalactic Ionizing Flux
• The Local Lyman-alpha Forest. II: Distribution of HI Absorbers, Doppler Widths, and Baryon Content
• The effects of UV background correlations on LyA forest flux statistics
• The Photon Underproduction Crisis
• Intergalactic Helium Absorption in Cold Dark Matter Models
• Cosmological and astrophysical constraints from the Lyman-alpha forest flux probability distribution function
• The Lyman-alpha forest and WMAP year three
• A Flat Photoionization Rate at 2<z<4.2: Evidence for a Stellar-Dominated UV Background and Against a Decline of Cosmic Star Formation Beyond z~3
• The Statistical and Physical Properties of the Low Redshift Lyman Alpha Forest Observed with HST/STIS
• Photon underproduction crisis: Are QSOs sufficient to resolve it?
• The Metagalactic Ionizing Background: A Crisis in UV Photon Production or Incorrect Galaxy Escape Fractions?
• Escape fraction of ionizing photons from galaxies at z=0--6
• A Spectroscopic Search for Leaking Lyman Continuum at z~0.7
• The Lyman Continuum Escape Fraction of Low-Mass Star-Forming Galaxies at z~1
• Constraints on the Primordial Power Spectrum from High Resolution Lyman-alpha Forest Spectra and WMAP
• Evolution of the Ionizing Background at High Redshifts
• The Spectral Slope and Escape Fraction of Bright Quasars at $z\sim 3.8$: the Contribution to the Cosmic UV Background
• New constraint on cosmological variation of the proton-to-electron mass ratio from Q0528-250
• Star formation history, dust attenuation and extragalactic background light
• Semi analytic approach to understanding the distribution of neutral hydrogen in the universe: Comparison of simulations with observations
• Intergalactic Lyman continuum photon budget in the past 5 billion years
• Absorption signatures of warm-hot gas at low redshift: Broad HI Lyman-Alpha Absorbers
• Artificial intelligence applied to the automatic analysis of absorption spectra. Objective measurement of the fine structure constant
• The Signatures of Large-scale Temperature and Intensity Fluctuations in the Lyman-alpha Forest
• The Lyman alpha forest flux probability distribution at z>3
• On the Significance of Absorption Features in HST/COS Data
• Sample variance and Lyman-alpha forest transmission statistics
• A high resolution study of intergalactic O VI absorbers at z~2.3
• The broadening of Lyman-alpha forest absorption lines
• Strong Clustering of High-Redshift Lyman-alpha Forest Absorption Systems
• Constraints on Cosmological Parameters from the Lyman-alpha Forest Power Spectrum and COBE-DMR
• Constraints on ionising photon production from the large-scale Lyman-alpha forest
• Measuring the equation of state of the high-z intergalactic medium using curvature statistics

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• Probing the thermal state of the intergalactic medium at $z>5$ with the transmission spikes in high-resolution Ly$\alpha$ forest spectra
• A consistent and robust measurement of the thermal state of the IGM at $2\le z\le 4$ from a large sample of Ly$\alpha$ forest spectra: Evidence for late and rapid HeII reionization
• Characterizing the Circumgalactic Medium of Nearby Galaxies with HST/COS and HST/STIS Absorption-Line Spectroscopy: II. Methods and Models
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• Three- and two-point spatial correlations of IGM at $z\sim 2$: Cloud based analysis using simulations
• MCMC determination of the cosmic UV background at $z\simeq 0$ from H$\alpha$ fluorescence
• Lognormal semi-numerical simulations of the Lyman-$\alpha$ forest: comparison with full hydrodynamic simulations
• Role of ionizing background on the non-thermal broadening inferred for the aligned absorbers
• Measurement of redshift-space two- and three-point correlation of Ly$\alpha$ absorbers at $1.7<z<3.5$: Implications on evolution of the physical properties of IGM
• Harvesting the Lyα forest with convolutional neural networks
• Physical conditions in high$-$z optically thin C III absorbers: Origin of cloud sizes and associated correlations
• Physical conditions and redshift evolution of optically thin C III absorbers: Low-z sample
• Equation of state of the intergalactic medium in the early Universe