Heterodyne spectroscopy for submillimeter and far-infrared wavelengths from 100 μm to 500 μm

Röser, Hans‐Peter

doi:10.1016/0020-0891(91)90127-2

Cited by 48 publications

(13 citation statements)

References 55 publications

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“…This antenna temperature is similar to that measured by a KAO instrument (Röser et al 1991), which has a source coupling efficiency roughly similar to our receiver.…”

Section: Resultssupporting

confidence: 83%

Ground-based terahertz CO spectroscopy towards Orion

Kawamura

Hunter

Tong

et al. 2002

A&A

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Abstract. Using a superconductive hot-electron bolometer heterodyne receiver on the 10-m Heinrich Hertz Telescope on Mount Graham, Arizona, we have obtained velocity-resolved 1.037 THz CO (J = 9 → 8) spectra toward several positions along the Orion Molecular Cloud (OMC-1) ridge. We confirm the general results of prior observations of high-J CO lines that show that the high temperature, T kin ≥ 130 K, high density molecular gas, n ≥ 10 6 cm −3 , is quite extended, found along a ∼4 region centered on BN/KL. However, our observations have significantly improved angular resolution, and with a beam size of θ FWHP ≈ 9 we are able to spatially and kinematically discriminate the emission originating in the extended quiescent ridge from the very strong and broadened emission originating in the compact molecular outflow. The ridge emission very close to the BN/KL region appears to originate from two distinct clouds along the line of sight with v LSR ≈ +6(1) km s

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“…This antenna temperature is similar to that measured by a KAO instrument (Röser et al 1991), which has a source coupling efficiency roughly similar to our receiver.…”

Section: Resultssupporting

confidence: 83%

Ground-based terahertz CO spectroscopy towards Orion

Kawamura

Hunter

Tong

et al. 2002

A&A

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“…8 transition of 12 C 16 O. This line has previously been observed in OMC-1 from the Kuiper Airborne Observatory ( Röser 1991;Betz & Boreiko 1993) and from the Heinrich Hertz Submillimeter Telescope ( Kawamura et al 2002), but never at more than a few points. Our map contains 35 pointings and covers $25 arcmin 2 at 84 00 resolution.…”

Section: Introductionmentioning

confidence: 82%

“…Because of mismatched baselines in the output of the three independent sections of our autocorrelation spectrometer, it was only possible to use the middle 110 channels (covering À47 to +47 km s À1 ) in our final spectra. Unfortunately, other observations of Orion KL in this transition (Röser 1991;Betz & Boreiko 1993;Kawamura et al 2002) and lower transitions (e.g., Schulz et al 1995;WMKH01) show plateau emission at velocities outside the À30 to +40 km s À1 range. Hence, the baselines subtracted from the (Á ¼ 0 00 , = 0 00 ) and (0 00 , À50 00 ) spectra, where the emission is widest in velocity, are likely to be inaccurate, and the integrated emission obtained from these spectra is significantly diminished.…”

Section: Resultsmentioning

confidence: 99%

A Map of OMC‐1 in COJ= 9→8

Marrone

Battat

Bensch

et al. 2004

ApJ

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The distribution of 12 C 16 O J ¼ 9 ! 8 (1.037 THz) emission has been mapped in OMC-1 at 35 points with 84 00 resolution. This is the first map of this source in this transition and only the second velocity-resolved groundbased observation of a line in the THz frequency band. There is emission present at all points in the map, a region roughly 4 0 ; 6 0 in size, with peak antenna temperature dropping only near the edges. Away from the Orion KL outflow, the velocity structure suggests that most of the emission comes from the OMC-1 photon-dominated region, with a typical line width of 3-6 km s À1 . Large velocity gradient modeling of the emission in J ¼ 9 ! 8 and six lower transitions suggests that the lines originate in regions with temperatures around 120 K and densities of at least 10 3.5 cm À3 near 1 C Ori and at the Orion bar, and from 70 K gas at around 10 4 cm À3 southeast and west of the bar. These observations are among the first made with the 0.8 m Smithsonian Astrophysical Observatory Receiver Lab Telescope, a new instrument designed to observe at frequencies above 1 THz from an extremely high and dry site in northern Chile.

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“…This is over a factor of four better than the best reported GaAs Schottky diode mixers at this frequency. 14 The mixers are designed using a microwave circuit simulation program which we have developed. 9 We calculate the rf coupling efficiency, which is the fraction of the radiation power received by the twin-slot antenna that is absorbed by the tunnel junction.…”

Section: ͓S0003-6951͑96͒00412-1͔mentioning

confidence: 99%

Low-noise 1 THz niobium superconducting tunnel junction mixer with a normal metal tuning circuit

Bin

Gaidis

Žmuidzinas

et al. 1996

Applied Physics Letters

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We describe a 1 THz quasioptical SIS mixer which uses a twin-slot antenna, an antireflection-coated silicon hyperhemispherical lens, Nb/Al-oxide/Nb tunnel junctions, and an aluminum normal-metal tuning circuit in a two-junction configuration. Since the mixer operates substantially above the gap frequency of niobium ͑Ͼ2⌬/hϳ700 GHz͒, a normal metal is used in the tuning circuit in place of niobium to reduce the Ohmic loss. The frequency response of the device was measured using a Fourier transform spectrometer and agrees reasonably well with the theoretical prediction. At 1042 GHz, the uncorrected double-sideband receiver noise temperature is 840 K when the physical temperature of the mixer is 2.5 K. This is the first SIS mixer which outperforms GaAs Schottky diode mixers by a large margin at 1 THz.

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Heterodyne spectroscopy for submillimeter and far-infrared wavelengths from 100 μm to 500 μm

Cited by 48 publications

References 55 publications

Ground-based terahertz CO spectroscopy towards Orion

Ground-based terahertz CO spectroscopy towards Orion

A Map of OMC‐1 in COJ= 9→8

Low-noise 1 THz niobium superconducting tunnel junction mixer with a normal metal tuning circuit

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