RHINO: A large horn antenna for detecting the 21cm global signal
arXiv:2410.00076 · doi:10.1093/rasti/rzaf046
Abstract
The sky-averaged brightness temperature of the 21cm line from neutral hydrogen provides a sensitive probe of the thermal state of the intergalactic medium, particularly before and during Cosmic Dawn and the Epoch of Reionisation. This `global signal' is faint, on the order of tens to hundreds of millikelvin, and spectrally relatively smooth, making it exceedingly difficult to disentangle from foreground radio emission and instrumental artefacts. In this paper, we introduce RHINO, an experiment based around a large horn antenna operating from 60-85 MHz. Horn antennas are highly characterisable and provide excellent shielding from their immediate environment, which are potentially decisive advantages when it comes to the beam measurement and modelling problems that are particularly challenging for this kind of experiment. The system also includes a novel continuous wave calibration source to control correlated gain fluctuations, allowing continuous monitoring of the overall gain level without needing to rapidly switch between the sky and a calibration source. Here, we describe the basic RHINO concept, including the antenna design, EM simulations, and receiver electronics. We use a basic simulation and analysis pipeline to study the impact of the limited bandwidth on recovery of physical 21cm global signal model parameters, and discuss a basic calibration scheme that incorporates the continuous wave signal. Finally, we report on the current state of a scaled-down prototype system under construction at Jodrell Bank Observatory.
arXiv comment19 pages, 17 figures. Matches published version
References in corpus (61)
- SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
- emcee: The MCMC Hammer
- The NumPy array: a structure for efficient numerical computation
- An absorption profile centred at 78 megahertz in the sky-averaged spectrum
- 21-cm Tomography of the Intergalactic Medium at High Redshift
- Possible interaction between baryons and dark-matter particles revealed by the first stars
- Reionization and Cosmology with 21 cm Fluctuations
- What Next-Generation 21 cm Power Spectrum Measurements Can Teach Us About the Epoch of Reionization
- ARCADE 2 Measurement of the Extra-Galactic Sky Temperature at 3-90 GHz
- Late-time cosmology with 21cm intensity mapping experiments
- Enhanced global signal of neutral hydrogen due to excess radiation at cosmic dawn
- Concerns about Modelling of the EDGES Data
- Evolution of the 21 cm signal throughout cosmic history
- An Improved Model of Diffuse Galactic Radio Emission from 10 MHz to 5 THz
- Constraining the unexplored period between reionization and the dark ages with observations of the global 21 cm signal
- Foregrounds in Wide-Field Redshifted 21 cm Power Spectra
- Neutral hydrogen surveys for high redshift galaxy clusters and proto-clusters
- Testing for calibration systematics in the EDGES low-band data using Bayesian model selection
- BIGHORNS - Broadband Instrument for Global HydrOgen ReioNisation Signal
- A Ground Plane Artifact that Induces an Absorption Profile in Averaged Spectra from Global 21-cm Measurements - with Possible Application to EDGES
- The Radio Background Below 100 MHz
- Results from EDGES High-Band: I. Constraints on Phenomenological Models for the Global cm Signal
- The REACH radiometer for detecting the 21-cm hydrogen signal from redshift 7.5 to 28
- HI Fluctuations at Large Redshifts: I--Visibility correlation
- SARAS 2: A Spectral Radiometer for probing Cosmic Dawn and the Epoch of Reionization through detection of the global 21 cm signal
- Calibration of the EDGES High-Band Receiver to Observe the Global 21-cm Signature from the Epoch of Reionization
- Absolute calibration of a wideband antenna and spectrometer for sky noise spectral index measurements
- A General Bayesian Framework for Foreground Modelling and Chromaticity Correction for Global 21cm Experiments
- Emulating the Global 21-cm Signal from Cosmic Dawn and Reionization
- HI Signal from Reionization Epoch
- Astrophysical Constraints from the SARAS3 non-detection of the Cosmic Dawn Sky-Averaged 21-cm Signal
- SARAS 3 CD/EoR Radiometer: Design and Performance of the Receiver
- TRIS I: Absolute Measurements of the Sky Brightness Temperature at 0.6, 0.82 and 2.5 GHz
- Quantifying Ionospheric Effects on Global 21-cm Observations
- Mapper of the IGM spin temperature: instrument overview
- Results from EDGES High-Band: II. Constraints on Parameters of Early Galaxies
- The Radio Synchrotron Background: Conference Summary and Report
- Validation of EDGES Low-Band Antenna Beam Model
- Prospects for precision cosmology with the 21 cm signal from the dark ages
- GMOSS: All-sky model of spectral radio brightness based on physical components and associated radiative processes
- Informing antenna design for sky-averaged 21-cm experiments using a simulated Bayesian data analysis pipeline
- The BINGO Project II: Instrument Description
- Antenna beam characterisation for the global 21cm experiment LEDA and its impact on signal model parameter reconstruction
- The role of soft photon injection and heating in 21 cm cosmology
- 21cmVAE: A Very Accurate Emulator of the 21-cm Global Signal
- The Second Radio Synchrotron Background Workshop: Conference Summary and Report
- Bayesian noise wave calibration for 21-cm global experiments
- A Bayesian Calibration Framework for EDGES
- A Bayesian approach to modelling spectrometer data chromaticity corrected using beam factors -- I. Mathematical formalism
- 21cmSense v2: A modular, open-source 21cm sensitivity calculator
- Simulating the Detection of the Global 21 cm Signal with MIST for Different Models of the Soil and Beam Directivity
- Planck LFI flight model feed horns
- Extracting the Global 21-cm signal from Cosmic Dawn and Epoch of Reionization in the presence of Foreground and Ionosphere
- The 21-cm Signal from the Cosmological Epoch of Recombination
- Analytic approximations of scattering effects on beam chromaticity in 21-cm global experiments
- Calibration Error in 21-centimeter Global Spectrum Experiments
- Receiver design for the REACH global 21-cm signal experiment
- Gain Stabilization for Radio Intensity Mapping using a Continuous-Wave Reference Signal
- L-BASS: a project to produce an absolutely calibrated 1.4 GHz sky map, I -- Scientific rationale and system overview
- The Bayesian Global Sky Model (B-GSM): Validation of a Data Driven Bayesian Simultaneous Component Separation and Calibration Algorithm for EoR Foreground Modelling
- Bayesian recalibration of flux scale factors in diffuse radio maps using low-resolution absolute radiometers
Cited by in corpus (4)
- Estimating Soil Electrical Parameters in the Canadian High Arctic from Impedance Measurements of the MIST Antenna Above the Surface
- ECHO21: a tool for modelling global 21-cm signal from dark ages to reionization
- Capturing System Drift with Time Series Calibration for Global 21-cm Cosmology Experiments
- Mitigating gain calibration errors from EoR observations with SKA1-Low AA*