15 research outputs found
SPICA—a large cryogenic infrared space telescope: unveiling the obscured universe
Measurements in the infrared wavelength domain allow us to assess directly
the physical state and energy balance of cool matter in space, thus enabling
the detailed study of the various processes that govern the formation and early
evolution of stars and planetary systems in galaxies over cosmic time. Previous
infrared missions, from IRAS to Herschel, have revealed a great deal about the
obscured Universe, but sensitivity has been limited because up to now it has
not been possible to fly a telescope that is both large and cold.
SPICA is a mission concept aimed at taking the next step in mid- and
far-infrared observational capability by combining a large and cold telescope
with instruments employing state-of-the-art ultra-sensitive detectors. The
mission concept foresees a 2.5-meter diameter telescope cooled to below 8 K.
With cooling provided by mechanical coolers instead of depending on a limited
cryogen supply, the mission lifetime can extend significantly beyond the
required three years.
SPICA offers instrumentation with spectral resolving powers ranging from R
~50 through 11000 in the 17-230 m domain as well as R~28.000 spectroscopy
between 12 and 18 m. Additionally SPICA will provide efficient 30-37
m broad band mapping, and polarimetric imaging in the 100-350 m
range. SPICA will provide unprecedented spectroscopic sensitivity of ~5 x
W/m (5/1hr) - at least two orders of magnitude
improvement over what has been attained to date.
With this exceptional leap in performance, new domains in infrared astronomy
will become accessible, allowing us, for example, to unravel definitively
galaxy evolution and metal production over cosmic time, to study dust formation
and evolution from very early epochs onwards, and to trace the formation
history of planetary systems.Comment: 34 pages, 22 figures, paper accepted for publication in PASA on 2nd
February 2018, part of the PASA SPICA Special Issu
Herschel-Heterodyne Instrument for the Far-Infrared (HIFI)
This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI) to be launched onboard of ESA's Herschel Space Observatory, by 2008. The instrument is designed to be electronically tunable over a wide and continuous frequency range in the Far Infrared, with velocity resolutions better than 0.1 km s^(-1) and a high sensitivity. This will allow detailed investigations of a wide variety of astronomical sources, ranging from solar system objects, star formation regions to nuclei of galaxies. The instrument comprises 5 frequency bands covering 480–1150 GHz with SIS mixers and a sixth dual frequency band, for the 1410–1910 GHz range, with Hot Electron Bolometer Mixers (HEB). The Local Oscillator (LO) subsystem consists of a Ka-band synthesizer followed by 14 chains of frequency multipliers, 2 chains for each frequency band. A pair of Auto-Correlators and a pair of Acousto-Optic spectrometers process the two IF signals from the dual-polarization front-ends to provide instantaneous frequency coverage of 4 GHz, with a set of resolutions (140 kHz to 1 MHz), better than <0.1 km s^(-1). After a successful qualification program, the flight instrument entered the testing phase. We will also report on the first pre-flight test and calibration results together with the expected in-flight performance
The Herschel-Heterodyne Instrument for the Far-Infrared (HIFI)
This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI) to be launched onboard of ESA's Herschel Space Observatory, by 2008. The instrument is designed to be electronically tunable over a wide and continuous frequency range in the Far Infrared, with velocity resolutions better than 0.1 km s-1 and a high sensitivity. This will allow detailed investigations of a wide variety of astronomical sources, ranging from solar system objects, star formation regions to nuclei of galaxies. The instrument comprises 5 frequency bands covering 480 1150 GHz with SIS mixers and a sixth dual frequency band, for the 1410 1910 GHz range, with Hot Electron Bolometer Mixers (HEB). The Local Oscillator (LO) subsystem consists of a Ka-band synthesizer followed by 14 chains of frequency multipliers, 2 chains for each frequency band. A pair of Auto-Correlators and a pair of Acousto-Optic spectrometers process the two IF signals from the dual-polarization front-ends to provide instantaneous frequency coverage of 4 GHz, with a set of resolutions (140 kHz to 1 MHz), better than < 0.1 km s-1. After a successful qualification program, the flight instrument entered the testing phase. We will also report on the first pre-flight test and calibration results together with the expected in-flight performance
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