The upGREAT 1.9 THz multi-pixel high resolution spectrometer for the SOFIA Observatory

Risacher, C.; Güsten, R.; Stutzki, J.; Hübers, Heinz‐Wilhelm; Bell, Andreas; Buchbender, C.; Büchel, D.; Csengeri, T.; Graf, U. U.; Heyminck, S.; Higgins, R.; Honingh, C. E.; Jacobs, K.; Klein, Bernd; Okada, Yoko; Parikka, A.; Pütz, P.; Reyes, Nicolás; Ricken, Oliver; Riquelme, D.; Simon, R.; Wiesemeyer, H.

doi:10.1051/0004-6361/201629045

Cited by 101 publications

(82 citation statements)

References 18 publications

(21 reference statements)

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“…The upGREAT was in the Low Frequency Array/High Frequency Array (LFA/HFA) configuration with both arrays operating in parallel. The 14 beam LFA array (Risacher et al 2016) was tuned to [C ii], while the 7 beam HFA array was tuned to the 3 P 1 -3 P 2 63 µm [O i] line. The spectrometer backends are the last generation of fast Fourier transform spectrometers (FFTS; Klein et al (2012)).…”

Section: Sofiamentioning

confidence: 99%

Opening the Treasure Chest in Carina

Mookerjea

Sandell

Güsten

et al. 2019

A&A

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We have mapped the G287.84-0.82 cometary globule (with the Treasure Chest cluster embedded in it) in the South Pillars region of Carina (i) in [C ii], 63 µm [O i] , and CO(11-10) using the heterodyne receiver array upGREAT on SOFIA and (ii) in J=2-1 transitions of CO, 13 CO, C 18 O and J=3-2 transitions of H 2 CO using the APEX telescope in Chile. We use these data to probe the morphology, kinematics, and physical conditions of the molecular gas and the photon dominated regions (PDRs) in G287.84-0.82. The velocity-resolved observations of [C ii] and [O i] suggest that the overall structure of the pillar (with red-shifted photo evaporating tails) is consistent with the effect of FUV radiation and winds from η Car and O stars in Trumpler 16. The gas in the head of the pillar is strongly influenced by the embedded cluster, whose brightest member is an O9.5 V star, CPD -59 • 2661. The emission of the [C ii] and [O i] lines peak at a position close to the embedded star, while all the other tracers peak at another position lying to the north-east consistent with gas being compressed by the expanding PDR created by the embedded cluster. The molecular gas inside the globule is probed with the J=2-1 transitions of CO and isotopologues as well as H 2 CO, and analyzed using a non-LTE model (escape-probability approach), while we use PDR models to derive the physical conditions of the PDR. We identify at least two PDR gas components; the diffuse part (∼10 4 cm −3 ) is traced by [C ii], while the dense (n ∼2-8 10 5 cm −3 ) part is traced by [C ii], [O i], CO(11-10). Using the the F=2-1 transition of [ 13 C ii] detected at 50 positions in the region, we derive optical depths (0.9-5), excitation temperatures of [C ii] (80-255 K), and N(C + ) of 0.3-1×10 19 cm −2 . The total mass of the globule is ∼ 1,000 M ⊙ , about half of which is traced by [C ii]. The dense PDR gas has a thermal pressure of 10 7 -10 8 K cm −3 , which is similar to the values observed in other regions.

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Section: Sofiamentioning

confidence: 99%

Opening the Treasure Chest in Carina

Mookerjea

Sandell

Güsten

et al. 2019

A&A

Self Cite

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“…The LFA receiver main commissioning results (derived characteristics such as beam efficiencies, beam sizes, observing modes summary, frequency and intensity calibrations) will be described in [41].…”

Section: Commissioning Flights Resultsmentioning

confidence: 99%

First Supra-THz Heterodyne Array Receivers for Astronomy With the SOFIA Observatory

Risacher

Güsten

Stützki³

et al. 2016

IEEE Trans. THz Sci. Technol.

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Abstract-We present the upGREAT THz heterodyne arrays for far-infrared astronomy. The Low Frequency Array (LFA) is designed to cover the 1.9-2.5 THz range using 2x7-pixel waveguide-based HEB mixer arrays in a dual polarization configuration. The High Frequency Array (HFA) will perform observations of the [OI] line at ~4.745 THz using a 7-pixel waveguide-based HEB mixer array. This paper describes the common design for both arrays, cooled to 4.5 K using closedcycle pulse tube technology. We then show the laboratory and telescope characterization of the first array with its 14 pixels (LFA), which culminated in the successful commissioning in May 2015 aboard the SOFIA airborne observatory observing the [CII] fine structure transition at 1.905 THz. This is the first successful demonstration of astronomical observations with a heterodyne focal plane array above 1 THz and is also the first time highpower closed-cycle coolers for temperatures below 4.5 K are operated on an airborne platform.

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“…Additionally before°ight, an electromagnetic interference test is conducted to verify that the aircraft will not interfere with the SI and vice versa. Commissioning then begins and is a combination of veri¯cation of SI performance on-sky as well as general operational capabilities (Adams et al, 2012;Colditz, 2017;Risacher et al, 2016;Smith et al, 2014).…”

Section: Integration Commissioning and Acceptancementioning

confidence: 99%

A Review of Science Ground Operations for the Stratospheric Observatory for Infrared Astronomy (SOFIA)

Ali

Alvarez

Cheng

et al. 2018

J. Astron. Instrum.

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The NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) is a 2.5 m telescope in a modi¯ed Boeing 747SP aircraft that is°own at high altitude to do unique astronomy in the infrared. SOFIA is a singular integration of aircraft operations, telescope design, and science instrumentation that delivers observational opportunities outside the capability of any other facility. The science ground operations are the transition and integration point of the science, aircraft, and telescope. We present the ground operations themselves and the tools used to prepare for mission success. Speci¯cally, we will discuss operations from science instrument delivery to aircraft operation and mission readiness. We will also provide a discussion of instrument life cycle including maintenance and repair, both before and after acceptance by the observatory as well as retirement. Included in that will be a description of the facilities and their development, an overview of the SOFIA telescope assembly simulator, our deployment capabilities, as well as an outlook to the future of novel science instrument support for SOFIA.

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The upGREAT 1.9 THz multi-pixel high resolution spectrometer for the SOFIA Observatory

Cited by 101 publications

References 18 publications

Opening the Treasure Chest in Carina

Opening the Treasure Chest in Carina

First Supra-THz Heterodyne Array Receivers for Astronomy With the SOFIA Observatory

A Review of Science Ground Operations for the Stratospheric Observatory for Infrared Astronomy (SOFIA)

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