L-BASS: a project to produce an absolutely calibrated 1.4 GHz sky map, I -- Scientific rationale and system overview
arXiv:2505.08465 · doi:10.1093/rasti/rzaf017
Abstract
L-BASS is an instrument designed to produce an absolutely calibrated map of the sky at a wavelength of 21 cm (L-band) with a radiometric accuracy of less than or equal to 0.1 K and with an angular resolution of 23 degrees. The prime motivations are to improve the temperature calibration of higher resolution maps and to investigate the steep spectrum radio background proposed by the ARCADE 2 team. The instrument consists of a pair of conical horn antennas which can scan independently in elevation; each antenna produces a circularly polarized output. The difference in signals from the antennas is measured with a continuous-comparison receiver connected to a digital spectrometer sampling the signal from 1400 MHz to 1425 MHz within the protected radio astronomy band. We describe the astrophysical motivation for the project, the design requirements and how these will be attained.
References in corpus (29)
- Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results
- Planck 2018 results. I. Overview and the cosmological legacy of Planck
- HI4PI: A full-sky HI survey based on EBHIS and GASS
- 4-Year COBE DMR Cosmic Microwave Background Observations: Maps and Basic Results
- An absorption profile centred at 78 megahertz in the sky-averaged spectrum
- The Microwave Anisotropy Probe (MAP) Mission
- Calibrator Design for the COBE Far Infrared Absolute Spectrophotometer (FIRAS)
- Planck 2018 results. VII. Isotropy and Statistics of the CMB
- ARCADE 2 Measurement of the Extra-Galactic Sky Temperature at 3-90 GHz
- Enhanced global signal of neutral hydrogen due to excess radiation at cosmic dawn
- Signature of Excess Radio Background in the 21-cm Global Signal and Power Spectrum
- The Radio Background Below 100 MHz
- Design, Implementation and Testing of the MAP Radiometers
- Planck pre-launch status: the Planck-LFI programme
- Planck 2015 results. V. LFI calibration
- 1/f noise and other systematic effects in the Planck-LFI radiometers
- A New 1.4GHz Radio Continuum Map of the Sky South of Declination +25 deg
- The C-Band All-Sky Survey (C-BASS): Design and capabilities
- TRIS I: Absolute Measurements of the Sky Brightness Temperature at 0.6, 0.82 and 2.5 GHz
- Contribution to the Diffuse Radio Background from Extragalactic Radio Sources
- TRIS II: search for CMB spectral distortions at 0.60, 0.82 and 2.5 GHz
- The Radio Synchrotron Background: Conference Summary and Report
- Estimating solar flux density at low radio frequencies using a sky brightness model
- MIGHTEE: Deep 1.4 GHz Source Counts and the Sky Temperature Contribution of Star Forming Galaxies and Active Galactic Nuclei
- The Deep Diffuse Extragalactic Radio Sky at 1.75 GHz
- The role of soft photon injection and heating in 21 cm cosmology
- The Second Radio Synchrotron Background Workshop: Conference Summary and Report
- The Global Magneto-Ionic Medium Survey: A Faraday Depth Survey of the Northern Sky Covering 1280-1750 MHz
- TRIS III: the diffuse galactic radio emission at