21CMMC: an MCMC analysis tool enabling astrophysical parameter studies of the cosmic 21 cm signal

By B. Greig, A. Mesinger. 2015

170 citations recorded by the source corpus.

We introduce 21CMMC: a parallelized, Monte Carlo Markov Chain analysis tool, incorporating the epoch of reionization (EoR) seminumerical simulation 21CMFAST. 21CMMC estimates astrophysical parameter constraints from 21 cm EoR experiments, accommodating a variety of EoR models, as well as priors on model parameters and the reionization history. To illustrate its utility, we consider two different EoR scenarios, one with a single population of galaxies (with a mass-independent ionizing efficiency) and a second, more general model with two different, feedback-regulated populations (each with mass-dependent ionizing efficiencies). As an example, combining three observations (z=8, 9 and 10) of the 21 cm power spectrum with a conservative noise estimate and uniform model priors, we find that interferometers with specifications like the Low Frequency Array/Hydrogen Epoch of Reionization Array (HERA)/Square Kilometre Array 1 (SKA1) can constrain common reionization parameters: the ionizing efficiency (or similarly the escape fraction), the mean free path of ionizing photons and the log of the minimum virial temperature of star-forming haloes to within 45.3/22.0/16.7, 33.5/18.4/17.8 and 6.3/3.3/2.4 per cent, ~$1\sigma$ fractional uncertainty, respectively. Instead, if we optimistically assume that we can perfectly characterize the EoR modelling uncertainties, we can improve on these constraints by up to a factor of ~few. Similarly, the fractional uncertainty on the average neutral fraction can be constrained to within $\lesssim10$ per cent for HERA and SKA1. By studying the resulting impact on astrophysical constraints, 21CMMC can be used to optimize (i) interferometer designs; (ii) foreground cleaning algorithms; (iii) observing strategies; (iv) alternative statistics characterizing the 21 cm signal; and (v) synergies with other observational programs.

Subfields: Aerospace Engineering, Astronomy and Astrophysics, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/061ddbbf5d52276d692f4c475380a57c83110229

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Aerospace Engineering

In Astronomy and Astrophysics

In Electrical and Electronic Engineering

Citations in the corpus

Inferences on the timeline of reionization at z ∼ 8 from the KMOS Lens-Amplified Spectroscopic Survey (2019, background): “…xhi(z) directly, for example by parametrising its evolution with redshift and inferring the values of its redshiftdependent parameters, or in a Markov Chain Monte Carlo exploration of IGM simulations to also infer relevant astrophysical parameters (Greig & Mesinger 2015; Greig & Mesinger 2017).”
Hydrogen Epoch of Reionization Array (HERA) (2016, methodology): “…for HERA—an instrument designed to ensure that foregrounds remain bounded within the wedge while delivering the sensitivity for high-significance detections of the 21 cm reionization power spectrum with established foreground filtering techniques (Pober et al. 2014b; Greig & Mesinger 2015).”
Charting the parameter space of the global 21-cm signal (2016, background): “We followed others (e.g., Greig & Mesinger 2015) in modeling this effect by imposing an upper limit on the mean free path of ionizing photons inside ionized regions, Rmfp.”
Inferring the astrophysics of reionization and cosmic dawn from galaxy luminosity functions and the 21-cm signal (2018, methodology): “In this section we provide a summary of 21cmmc (Greig & Mesinger 2015) used to constrain the astrophysical parameters described in section 2.4.”