2004/03/31 by J. W. Fowler, Joseph W. Fowler, W. B. Doriese +18 · 1 citation
Physics and Astronomy · #Cosmology and Gravitation Theories #Radio Astronomy Observations and Technology #Superconducting and THz Device Technology #astro-ph
paper · pdf · doi:10.1086/426393
published as Astrophys. J. Suppl. 156 (2005) 1-11 · 12 pages, 4 figures. v2: Final ApJS version; rewritten analysis section made more clear
openalex publication_date 2004/12/17 · arxiv created 2005/01/27 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We report on the design, first observing season, and analysis of data from a new prototype millimeter-wave interferometer, MINT. MINT consists of four 145 GHz SIS mixers operating in double-sideband mode in a compact heterogeneous configuration. The signal band is subdivided by a monolithic channelizer, after which the correlations between antennas are performed digitally. The typical receiver sensitivity in a 2 GHz band is 1.4 mK s 1/2 . The primary beams are 0 45 and 0 30 FWHM, with fringe spacing as small as 0 1. MINT observed the cosmic microwave background (CMB) from Cerro Toco, in the Chilean Altiplano. The site quality at 145 GHz is good, with median nighttime atmospheric temperature of 9 K at zenith (exclusive of the CMB). Repeated observations of Mars, Jupiter, and a telescope-mounted calibration source establish the phase and magnitude stability of the system. MINT is the first interferometer dedicated to CMB studies to operate above 50 GHz. The same type of system can be used to probe the Sunyaev-Zel'dovich effect in galaxy clusters near the SZ null at 217 GHz. We give the essential features of MINT and present an analysis of sideband-separated, digitally sampled data recorded by the array. Based on 215 hours of data taken in late 2001, we set an upper limit on the CMB anisotropy in a band of width Δℓ = 700 around ℓ = 1540 of δ T < 105 μK (95% confidence). Increased sensitivity can be achieved with more integration time, greater bandwidth, and more elements.