Forecast measurement of the 21 cm global spectrum from Lunar orbit with the Vari-Zeroth-Order Polynomial (VZOP) method
arXiv:2406.17000 · doi:10.1017/pasa.2025.17
Abstract
The cosmic 21 cm signal serves as a crucial probe for studying the evolutionary history of the Universe. However, detecting the 21 cm signal poses significant challenges due to its extremely faint nature. To mitigate the interference from the Earth's radio frequency interference (RFI), the ground and the ionospheric effects, the Discovering the Sky at the Longest Wavelength (DSL) project will deploy a constellation of satellites in Lunar orbit, with its high-frequency daughter satellite tasked with detecting the global 21 cm signal from cosmic dawn and reionization era (CD/EoR). We intend to employ the Vari-Zeroth-Order Polynomial (VZOP) for foreground fitting and subtracting. We have studied the effect of thermal noise, thermal radiation from the Moon, the Lunar reflection, anisotropic frequency-dependent beam, inaccurate antenna beam pattern, and RFI contamination. We discovered that the RFI contamination can significantly affect the fitting process and thus prevent us from detecting the signal. Therefore, experimenting on the far side of the moon is crucial. We also discovered that using VZOP together with DSL, after 1080 orbits around the Moon, which takes about 103 days, we can successfully detect the CD/EoR 21 cm signal.
20 pages, 19 figures, 2 tables, Accepted for publication in PASA
References in corpus (27)
- Testing for calibration systematics in the EDGES low-band data using Bayesian model selection
- BIGHORNS - Broadband Instrument for Global HydrOgen ReioNisation Signal
- The REACH radiometer for detecting the 21-cm hydrogen signal from redshift 7.5 to 28
- Foreground Model and Antenna Calibration Errors in the Measurement of the Sky-Averaged λ21 cm Signal at z~20
- The subtlety of Ly-a photons: changing the expected range of the 21-cm signal
- A General Bayesian Framework for Foreground Modelling and Chromaticity Correction for Global 21cm Experiments
- A Space-Based Observational Strategy for Characterizing the First Stars and Galaxies Using the Redshifted 21-cm Global Spectrum
- Discovering the Sky at the Longest wavelengths with a lunar orbit array
- SARAS 3 CD/EoR Radiometer: Design and Performance of the Receiver
- GLOBALEMU: A novel and robust approach for emulating the sky-averaged 21-cm signal from the cosmic dawn and epoch of reionisation
- Quantifying Ionospheric Effects on Global 21-cm Observations
- A 21-cm power spectrum at 48 MHz, using the Owens Valley Long Wavelength Array
- Informing antenna design for sky-averaged 21-cm experiments using a simulated Bayesian data analysis pipeline
- Antenna beam characterisation for the global 21cm experiment LEDA and its impact on signal model parameter reconstruction
- Lunar Orbit Measurement of Cosmic Dawn 21 cm Global Spectrum
- An Ultra-long Wavelength Sky Model with Absorption Effect
- Bayesian noise wave calibration for 21-cm global experiments
- A Bayesian Calibration Framework for EDGES
- The 21-cm forest as a simultaneous probe of dark matter and cosmic heating history
- Extracting the Global 21-cm signal from Cosmic Dawn and Epoch of Reionization in the presence of Foreground and Ionosphere
- Analytic approximations of scattering effects on beam chromaticity in 21-cm global experiments
- Calibration Error in 21-centimeter Global Spectrum Experiments
- Lunar Far-Side Radio Arrays: A Preliminary Site Survey
- Direct Parameter Inference from Global EoR Signal with Bayesian Statistics
- A Bayesian Method to Mitigate the Effects of Unmodelled Time-Varying Systematics for 21-cm Cosmology Experiments
- Measuring the global 21-cm signal with the MWA-II: improved characterisation of lunar-reflected radio frequency interference
- Detecting Cosmic 21 cm Global Signal Using an Improved Polynomial Fitting Algorithm