On the Abundance of Primordial Helium

Abstract

We have used recent observations of helium-4, nitrogen and oxygen from some four dozen, low metallicity, extra-galactic HII regions to define mean $N$ versus $O$, ${}^{4}He$ versus $N$ and ${}^{4}He$ versus $O$ relations which are extrapolated to zero metallicity to determine the primordial ${}^{4}He$ mass fraction $Y_P$. The data and various subsets of the data, selected on the basis of nitrogen and oxygen, are all consistent with $Y_P=0.232\pm 0.003$. For the 2$\sigma$ (statistical) upper bound we find $Y_P^{2\sigma }\le 0.238$. Estimating a 2\% systematic uncertainty $({\sigma }_{syst}=\pm 0.005)$ leads to a maximum upper bound to the primordial helium mass fraction: $Y_P^{MAX}=Y_P^{2\sigma }+{\sigma }_{syst}\le 0.243$. We compare these upper bounds to $Y_P$ with recent calculations of the predicted yield from big bang nucleosynthesis to derive upper bounds to the nucleon-to-photon ratio $\eta$ (${\eta }_{10}\equiv 10^{10}\eta$) and the number of equivalent light (\lsim 10 MeV) neutrino species. For $Y_P\le 0.238$ ($0.243$), we find ${\eta }_{10}\le 2.5(3.9)$ and $N_{\nu }\le 2.7(3.1)$. If indeed $Y_P\le 0.238$, then BBN predicts enhanced production of deuterium and helium-3 which may be in conflict with the primordial abundances inferred from model dependent (chemical evolution) extrapolations of solar system and interstellar observations. Better chemical evolution models and more data - especially $D$-absorption in the QSO Ly-$\alpha$ clouds - will be crucial to resolve this potential crisis for BBN. The larger upper bound, $Y_P\le 0.243$ is completely

21 pages, LaTeX, 6 postscript figures available upon request, UMN-TH-1230

Cited by in corpus (114)

• The Cosmic Baryon Budget
• Big-Bang Nucleosynthesis and Hadronic Decay of Long-Lived Massive Particles
• The Evolution of the Elemental Abundances in the Gas and Dust Phases of the Galaxy
• Big Bang nucleosynthesis and physics beyond the Standard Model
• Revisiting the bound on axion-photon coupling from Globular Clusters
• Primordial Nucleosynthesis: Theory and Observations
• The Deuterium Abundance Towards Q1937-1009
• New BBN limits on Physics Beyond the Standard Model from He4
• Signatures of Relativistic Neutrinos in CMB Anisotropy and Matter Clustering
• The black hole and FRW geometries of non-relativistic gravity
• Big-bang Nucleosynthesis Enters the Precision Era
• Asymmetric Inflationary Reheating and the Nature of Mirror Universe
• Lorentz-Violating Vector Fields Slow the Universe Down
• The Primordial Abundance of He4: An Update
• Sharpening the predictions of big-bang nucleosynthesis
• Big-Bang Nucleosynthesis with Unstable Gravitino and Upper Bound on the Reheating Temperature
• Helium abundance in the most metal-deficient blue compact galaxies: I Zw 18 and SBS 0335-052
• The primordial abundance of 4He: a self-consistent empirical analysis of systematic effects in a large sample of low-metallicity HII regions
• Early-universe constraints on a Primordial Scaling Field
• Two measures of the shape of the Milky Way's dark halo
• Big Bang Nucleosynthesis in Crisis?
• Effective number of neutrinos and baryon asymmetry from BBN and WMAP
• The High-Redshift He II Gunn-Peterson Effect: Implications and Future Prospects
• Precision Prediction for the Big-Bang Abundance of Primordial Helium
• Halo Star Lithium Depletion
• Atomic Hydrogen Gas in Dark-Matter Minihalos and the Compact High Velocity Clouds
• Big Bang Nucleosynthesis with Long Lived Charged Massive Particles
• The response of primordial abundances to a general modification of $G_{\mathrm{N}}$ and/or of the early universe expansion rate
• Estimating reaction rates and uncertainties for primordial nucleosynthesis
• On the Evolution of Helium in Blue Compact Galaxies
• Cosmological variation of deuteron binding energy, strong interaction and quark masses from big bang nucleosynthesis
• Luminous and Dark Matter in the Milky Way
• Assessing Big-Bang Nucleosynthesis
• Big bang nucleosynthesis limit on N_nu
• Selected topics in scalar-tensor theories and beyond
• BBN For Pedestrians
• Lines in the cosmic microwave background spectrum from the epoch of cosmological helium recombination
• Testing CNO Enrichment Scenarios in Metal-poor Galaxies with HST Spectroscopy
• The Effects of an Early Galactic Wind on the Evolution of D, \he3 and Z
• ΔY/ ΔZ from the analysis of local K dwarfs
• Is High Primordial Deuterium Consistent With Galactic Evolution?
• Cosmological Implications of Two Conflicting Deuterium Abundances
• Update on neutrino mixing in the early Universe
• Model Independent Predictions of Big Bang Nucleosynthesis from \he4 and \li7: Consistency and Implications
• Observational Constraints On Power-Law Cosmologies
• The Solar Helium Abundance in the Outer Corona Determined from Observations with SUMER/SOHO
• The Deuterium Abundance at z=0.701 towards QSO 1718+4807
• Testing Standard and Degenerate Big Bang Nucleosynthesis with BOOMERanG and MAXIMA-1
• The age of the oldest globular clusters
• Geometrical Effects of Baryon Density Inhomogeneities on Primordial Nucleosynthesis
• Extended quintessence and the primordial helium abundance
• The Big-Bang Nucleosynthesis Limit to the Number of Neutrino Species
• Confrontation of MOND Predictions with WMAP First Year Data
• No Crisis for Big Bang Nucleosynthesis
• Primordial Nucleosynthesis with varying fundamental constants: A semi-analytical approach
• The Primordial Helium Abundance: Towards Understanding and Removing the Cosmic Scatter in the dY/dZ Relation
• Primordial black holes in braneworld cosmologies: astrophysical constraints
• Model-Independent Predictions of Big Bang Nucleosynthesis
• Cosmological Nucleosynthesis and Active-Sterile Neutrino Oscillations with Small Mass Differences: The Nonresonant Case
• Ionization Corrections For Low-Metallicity H II Regions and the Primordial Helium Abundance
• Is there a need and another way to measure the Cosmic Microwave Background temperature more accurately?
• BBN And CMB Constraints On Dark Energy
• Nucleosynthesis in Power-Law Cosmologies
• Low Mass Stars and the He3 Problem
• Cosmological nucleosynthesis and active-sterile neutrino oscillations with small mass differences: The resonant case
• A New Look At Neutrino Limits From Big Bang Nucleosynthesis
• A Big Bang Nucleosynthesis Likelihood Analysis of the Baryon-to-Photon Ratio and the Number of Light Particle Degrees of Freedom
• The Evolution of Helium and Hydrogen Ionization Corrections as HII Regions Age
• Temperature Fluctuations and Abundances in HII Galaxies
• A Stochastic Approach to Chemical Evolution
• A Search for Stars of Very Low Metal Abundance. IV. uvbyCa Observations of Metal-Weak Candidates from the Northern HK Survey
• Addendum to: Update on neutrino mixing in the early Universe
• Primordial Nucleosynthesis, Majorons and Heavy Tau Neutrinos
• Active-Sterile neutrino oscillations and BBN+CMBR constraints
• The Effect of Bound Dineutrons upon BBN
• Helium and Deuterium Abundances as a Test for the Time Variation of the Fine Structure Constant and the Higgs Vacuum Expectation Value
• Effect of Finite Mass on Primordial Nucleosynthesis
• Constraining the Dark Universe
• Collisional excitation of hydrogen and the determination of the primordial helium abundance from H II regions
• BBN and Lambda_QCD
• A Bayesian Estimate of the Primordial Helium Abundance
• An improved cosmological bound on the tau-neutrino mass
• Non-Nucleosynthetic Constraints on the Baryon Density and Other Cosmological Parameters
• Inhomogeneous Big Bang Nucleosynthesis and the High Baryon Density Suggested by Boomerang and MAXIMA
• Solving the Crisis in Big-Bang Nucleosynthesis by the Radiative Decay of an Exotic Particle
• Nucleosynthesis and the mass of the tau neutrino
• Observational Cosmology
• Cosmological Implications of the First Measurement of the Local ISM Abundance of ${}^3$He
• Testing Primordial Abundances With Sterile Neutrinos
• Nucleosynthesis Limits on the Mass of Long Lived Tau and Muon Neutrinos
• Emission-line Helium Abundances in Highly Obscured Nebulae
• Cosmological study of a symmetric teleparallel gravity model
• Baryonic Mass Fraction in Rich Clusters and the Total Mass Density in the Cosmos
• Neutron Diffusion and Nucleosynthesis in an Inhomogeneous Big Bang Model
• An X-ray and Optical Study of Matter Distribution in the Galaxy Cluster A 2319
• On the primordial helium content: CMB and stellar constraints
• Determination of Omega_b From Big Bang Nucleosynthesis in the Presence of Regions of Antimatter
• Big Bang Nucleosynthesis with $f(R)$ gravity scalarons and astrophysical consequences
• Chemical Enrichment from Massive Stars in Starbursts
• Big Bang Nucleosynthesis
• Big Bang Nucleosynthesis
• Big Bang Nucleosynthesis
• Big Bang Nucleosynthesis
• Primordial Abundances of ^6Li, ^9Be, and ^11B with Neutrino Degeneracy and Gravitational Constant Variation
• Sterile Neutrinos in astrophysical and cosmological sauce
• Post freeze-out annihilations in the early universe
• Non-BBN Constraints On The Key Cosmological Parameters
• Static Universe: Infinite, Eternal and Self-Sustainable
• Primordial Nucleosynthesis, Cosmic Microwave Background and Neutrinos
• Invisible Matter
• Big Bang Nucleosynthesis, Population III, and Stellar Genetics in the Galactic Halo
• Astroparticle physics - A Personal Outlook
• How to get less helium and more neutrinos from BBN
• The BBN Manifesto