Probing large scale filaments with HI and ${}^3$HeII

Abstract

We explore the observability of the neutral hydrogen (HI) and the singly-ionized isotope helium-3 (${}^3$HeII) in the intergalactic medium (IGM) from the Epoch of Reionization down to the local Universe. The hyperfine transition of ${}^3$HeII, which is not as well known as the HI transition, has energy splitting corresponding to 8 cm. It also has a larger spontaneous decay rate than that of neutral hydrogen, whereas its primordial abundance is much smaller. Although both species are mostly ionized in the IGM, the balance between ionization and recombination in moderately high density regions renders them abundant enough to be observed. We estimate the emission signal of both hyperfine transitions from large scale filamentary structures and discuss the prospects for observing them with current and future radio telescopes. We conclude that HI in filaments is possibly observable even with current telescopes after 100 hours of observation. On the other hand, ${}^3$HeII is only detectable with future telescopes, such as SKA, after the same amount of time.

21 pages, 13 figures, 2 tables, accepted to MNRAS

References in corpus (13)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• The Five-Hundred-Meter Aperture Spherical Radio Telescope (FAST) Project
• Baryon Acoustic Oscillation Intensity Mapping as a Test of Dark Energy
• Measurement of 21 cm brightness fluctuations at z ~ 0.8 in cross-correlation
• Foreground simulations for the LOFAR - Epoch of Reionization Experiment
• The Scale of the Problem : Recovering Images of Reionization with GMCA
• The Effects of Dark Matter Decay and Annihilation on the High-Redshift 21 cm Background
• Non-parametric foreground subtraction for 21cm epoch of reionization experiments
• The Scattering of Lyman-series Photons in the Intergalactic Medium
• Spin Exchange Rates in Electron-Hydrogen Collisions
• Spin Exchange Rates in Proton-Hydrogen Collisions
• Measuring the Primordial Deuterium Abundance During the Cosmic Dark Ages
• Particle decay in the early universe: predictions for 21 cm

Cited by in corpus (10)

• The large-scale environment from cosmological simulations I: The baryonic cosmic web
• Studying high-z galaxies with [CII] intensity mapping
• Probing the high-z IGM with the hyperfine transition of ${}^3$He${}^{+}$
• Thinking outside the halo: Tracing the large-scale distribution of diffuse cosmic metals with semi-analytic models
• Probing primordial ${}^3$He from hyperfine line afterglows around supercritical black holes
• Simulating the epoch of Helium Reionization in photon-conserving semi-numerical code SCRIPT
• Pre-heating of the intergalactic medium by gravitational collapse and ultraviolet background
• FAST drift scan survey for HI intensity mapping: simulation on hunting HI filament with pairwise stacking
• Detecting the signature of helium reionization through 3HeII 3.46cm line-intensity mapping
• Primordial helium-3 redux: The helium isotope ratio of the Orion nebula