FORCAST: A Mid-Infrared Camera for SOFIA

Herter, T.; Adams, Joseph D.; Gull, G. E.; Schoenwald, Justin; Keller, L. D.; Pirger, Bruce; Henderson, C.; Stacey, G. J.; Nikola, Thomas; Buizer, James M. De; Vacca, William D.; Ennico, Kimberly

doi:10.1142/s2251171718400056

Cited by 32 publications

(28 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…SOFIA is a 2.5 m telescope flown on a Boeing 747-SP aircraft used for infrared and submillimetre astronomy 29 . The FORCAST instrument combines a spectrograph and a mid-infrared camera using a 256 × 256 Si Blocked-Impurity-Band infrared focal plane array 30 . For lunar observations, we used the FORCAST G063 filter with the long-slit (2.4 × 191″) low-resolution mode to provide a spectral coverage of 5 to 8 µm.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Molecular water detected on the sunlit Moon by SOFIA

et al. 2020

View full text Add to dashboard Cite

Widespread hydration was detected on the lunar surface through observations of a characteristic absorption feature at 3 µm by three independent spacecraft 1-3. Whether the hydration is molecular water (H 2 O) or other hydroxyl (OH) compounds is unknown and there are no established methods to distinguish the two using the 3 µm band 4. However, a fundamental vibration of molecular water produces a spectral signature at 6 µm that is not shared by other hydroxyl compounds 5. Here, we present observations of the Moon at 6 µm using the NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA). Observations reveal a 6 µm emission feature at high lunar latitudes due to the presence of molecular water on the lunar surface. On the basis of the strength of the 6 µm band, we estimate abundances of about 100 to 400 µg g −1 H 2 O. We find that the distribution of water over the small latitude range is a result of local geology and is probably not a global phenomenon. Lastly, we suggest that a majority of the water we detect must be stored within glasses or in voids between grains sheltered from the harsh lunar environment, allowing the water to remain on the lunar surface. Using SOFIA and the Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST) instrument, we conducted observations of the lunar surface at 6 µm on 31 August 2018 in a search for molecular water. FORCAST is well suited to look for 6 µm lunar water due to its wavelength coverage from 5 to 8 µm, spectral resolution of R = 200 and high signal-to-noise ratios. The FORCAST entrance slit that defines the portion of the Moon observed is 2.4 × 191 arcsec sampled with 248 pixels. At the lunar centre of disk the slit has a spatial extent of 4.8 × 1.5 km 2 (the spatial resolution near the limb is lower due to foreshortening). During the observations, the Moon was at a phase angle of 57.5°. We observed a region at high southern latitudes near Clavius crater and a low-latitude portion of Mare Serenitatis (Extended Data Fig. 1). Details regarding observations, site selection and data reduction can be found in the Methods. Data from SOFIA reveal a strong 6 µm emission band at Clavius crater and the surrounding terrain (Fig. 1) relative to the control location near the lunar equator, which shows low hydration in some analyses (see Methods). All spectra from the Clavius region exhibit this 6 µm emission feature. The majority of these emission peaks (98%) exceed 2σ significance relative to the background noise, and about 20% exceed 4σ significance (Extended Data Fig. 2). To determine whether the spectral properties of the lunar 6 µm band are consistent with spectra of particulate water-bearing materials, we examined other planetary materials that show a 6 µm

show abstract

Section: Methodsmentioning

confidence: 99%

“…The data are in the form of spectral images that are 248 × 248 pixels, where the x axis is wavelengths covering 5 to 8 µm and the y axis is the spatial position on the Moon along the spectrograph slit. Data were processed using the standard SOFIA corrections 30 . The processing steps are shown in Supplementary Fig.…”

Section: Methodsmentioning

confidence: 99%

Molecular water detected on the sunlit Moon by SOFIA

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The wavelength coverage and capabilities of MISC-T and MISC WFI partly overlap with those of JWST/mid-infrared instrument (MIRI), 18 SOFIA instruments: Faint Object infrared Camera for the SOFIA Telescope, 19 Echeleon-Cross-Echelle Spectrograph, 20 Space Infrared Telescope for Cosmology and Astrophysics (SPICA, a mission under study for ESA/JAXA) instrument studies: SPICA Mid-infrared Instrument (SMI, current), 21 Mid-infrared Camera and Spectrometer, 22 SPICA Coronagraph Instrument (SCI), 23 Tokyo Atacama Observatory (TAO) Multi-field Imager for gazing at the UnKnown Universe (MIMIZUKU), 24,25 Spitzer/IRS, 26 and Thirty Meter Telescope Mid-Infrared Camera High-disperser & IFU (MICHI), 27 and NEOSM. 9 Particularly, the long-wavelength HgCdTe detectors, which are employed in MISC-T-S and T-M, have been developed for the NEOSM (See details for Ref.…”

Section: Misc Heritage and Maturitymentioning

confidence: 99%

Mid-infrared spectrometer and camera for the Origins Space Telescope

Sakon

Roellig

Ennico-Smith

et al. 2021

J. Astron. Telesc. Instrum. Syst.

View full text Add to dashboard Cite

The mid-infrared spectrometer and camera transit spectrometer (MISC-T) is one of the three baseline instruments for Origins Space Telescope (Origins) and provides the capability to assess the habitability of nearby exoplanets and search for signs of life. MISC-T employs a densified pupil optical design, and HgCdTe and Si:As detector arrays. This optical design allows the instrument to be relatively insensitive to minor line-of-sight pointing drifts and telescope aberrations, and the detectors do not require a sub-Kelvin refrigerator. MISC-T has three science spectral channels that share the same field-of-view by means of beam splitters, and all channels are operated simultaneously to cover the full spectral range from 2.8 to 20 μm at once with exquisite stability and precision (<5 ppm between 2.8 to 11 μm, <20 ppm between 11 and 20 μm). A Lyot-coronagraph-based tip-tilt sensor located in the instrument fore-optics uses the light reflected by a field stop, which corresponds to 0.3% of the light from the target, to send fine pointing information to the field steering mirror in the Origins telescope. An additional MISC Wide Field Imager (WFI) is studied as an upscope option for the Origins. MISC-WFI offers a wide field imaging (3 0 × 3 0) and low-resolution spectroscopic capability with filters and gratingprisms (grisms) covering 5 to 28 μm. The imaging capability of the MISC-WFI will be used for general science objectives. The low-resolution spectroscopic capability in MISC-WFI with a resolving power R (¼ λ∕Δλ) of a few hundreds will be used to measure the mid-infrared dust features and ionic lines at z up to ∼1 in the Origins mission's Rise of Metals and Black Hole

show abstract

“…Observations of the galactic center presented by Iserlohe et al 13 showed how the ability of FIFI-LS to quickly map large areas in multiple fine diagnostic lines was used to characterize photodissociation regions (PDR). Line emission maps of four lines: [CII], [OI] 63 and 145 μm, and CO J ¼ 14 to 13 as well as the FIR flux derived using FIFI-LS, FORCAST, 14 and PACS continuum data were used to infer the density and FUV-field using PDR models. 15 The analysis by Iserlohe et al shows that the [OI] line fluxes at ∼63 μm have to be affected by self-absorption, whereas there is significant contribution to the [CII] line flux not originating from the probed PDR.…”

Section: Science With Fifi-lsmentioning

confidence: 99%

Upgrading the Field-Imaging Far-Infrared Line Spectrometer for the Stratospheric Observatory for Infrared Astronomy with kinetic inductance detectors: enabling large sample (extragalactic) surveys

Colditz

Looney

Bigiel

et al. 2021

J. Astron. Telesc. Instrum. Syst.

View full text Add to dashboard Cite

We present the initial design, performance improvements, and science opportunities for an upgrade to the Field-Imaging Far-Infrared Line Spectrometer (FIFI-LS). FIFI-LS efficiently measures fine structure cooling lines, delivering critical constraints of the interstellar medium and star-forming environments. The Stratospheric Observatory for Infrared Astronomy (SOFIA) provides the only far-infrared (FIR) observational capability in the world, making FIFI-LS a workhorse for FIR lines, combining optimal spectral resolution and a wide velocity range. Its continuous coverage of 51 to 203 μm makes FIFI-LS a versatile tool to investigate a multitude of diagnostic lines within our galaxy and in extragalactic environments. The sensitivity and field of view (FOV) of FIFI-LS are limited by its 90s-era photoconductor arrays. These limits can be overcome by upgrading the instrument using the latest developments in kinetic inductance detectors (KIDs). KIDs provide sensitivity gains in excess of 1.4 and allow larger arrays, enabling an increase in pixel count by an order of magnitude. This increase allows a wider FOV and instantaneous velocity coverage. The upgrade provides gains in point source observation speed by a factor >2 and in mapping speed by a factor >3.5, enabled by the improved sensitivity and pixel count. This upgrade has been proposed to NASA in response to the 2018 SOFIA Next Generation Instrumentation call. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

show abstract

FORCAST: A Mid-Infrared Camera for SOFIA

Cited by 32 publications

References 31 publications

Molecular water detected on the sunlit Moon by SOFIA

Molecular water detected on the sunlit Moon by SOFIA

Mid-infrared spectrometer and camera for the Origins Space Telescope

Upgrading the Field-Imaging Far-Infrared Line Spectrometer for the Stratospheric Observatory for Infrared Astronomy with kinetic inductance detectors: enabling large sample (extragalactic) surveys

Contact Info

Product

Resources

About