Propynal, an interstellar molecule with an exceptionally strong C $\equiv$ C infrared band – laboratory infrared data and applications
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Reggie L Hudson↗
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Near-infrared Reflectance of Rocks at High Temperature: Preliminary Results and Implications for Near-infrared Emissivity of Venus’s Surface
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Allan H. Treiman↗
Infrared Aerosol Radiative Forcing at the Surface and the Top of the Atmosphere
We study the clear-sky aerosol radiative forcing at infrared wavelengths using data from the Aerosol Characterization Experiment (ACE-Asia) cruise of the NOAA R/V Ronald H. Brown. Limited number of data points is analyzed mostly from ship and collocated satellite values. An optical model is derived from chemical measurements, lidar profiles, and visible extinction measurements which is used to and estimate the infrared aerosol optical thickness and the single scattering albedo. The IR model results are compared to detailed Fourier Transform Interferometer based infrared aerosol forcing estimates, pyrgeometer based infrared downward fluxes, and against the direct solar forcing observations. This combined approach attests for the self-consistency of the optical model and allows to derive quantities such as the infrared forcing at the top of the atmosphere or the infrared optical thickness. The mean infrared aerosol optical thickness at 10 microns is 0.08 and the single scattering albedo is 0.55. The modeled infrared aerosol forcing reaches 10 W/sq m during the cruise, which is a significant contribution to the total direct aerosol forcing. The surface infrared aerosol radiative forcing is between 10 to 25% of the shortwave aerosol forcing. The infrared aerosol forcing at the top of the atmosphere can go up to 19% of the solar aerosol forcing. We show good agreement between satellite (CERES instrument) retrievals and model results at the top of the atmosphere. Over the Sea of Japan, the average infrared radiative forcing is 4.6 W/sq m in the window region at the surface and it is 1.5 W/sq m at top of the atmosphere. The top of the atmosphere IR forcing efficiency is a strong function of aerosol temperature while the surface IR forcing efficiency varies between 37 and 55 W/sq m (per infrared optical depth unit). and changes between 10 to 18 W/sq m (per infrared optical depth unit).
Markowicz, Krzysztof M.↗
Infrared astronomy - Scientific/military thrusts and instrumentation; Proceedings of the Meeting, Washington, DC, April 21, 22, 1981
A series of papers on infrared astronomy is presented. Among the topics discussed are those concerning programs, such as NASA's planning, the Cosmic Background Explorer and a cryogenic infrared radiance instrument for the Space Shuttle. Articles on infrared astronomy technology include those on an infrared camera for 10-micron astronomy, bulk and integrated acousto-optic spectrometers for molecular astronomy with heterodyne spectrometers, and airborne measurements of infrared atmospheric radiance and sky noise. Several papers on infrared astronomy spectroscopy are included, such as infrared heterodyne spectroscopy and infrared lines from shocked galactic gases. Among the articles on infrared astronomy catalogues and operations are discussions of groundbased infrared measurements using the AMOS/MOTIF facility and the prediction of infrared celestial source counts.
Boggess, N. W.↗
Noninvasive, near infrared spectroscopic-measured muscle pH and PO2 indicate tissue perfusion for cardiac surgical patients undergoing cardiopulmonary bypass
OBJECTIVE: To determine whether near infrared spectroscopic measurement of tissue pH and Po2 has sufficient accuracy to assess variation in tissue perfusion resulting from changes in blood pressure and metabolic demand during cardiopulmonary bypass. DESIGN: Prospective clinical study. SETTING: Academic medical center. SUBJECTS: Eighteen elective cardiac surgical patients. INTERVENTION: Cardiac surgery under cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: A near infrared spectroscopic fiber optic probe was placed over the hypothenar eminence. Reference Po2 and pH sensors were inserted in the abductor digiti minimi (V). Data were collected every 30 secs during surgery and for 6 hrs following cardiopulmonary bypass. Calibration equations developed from one third of the data were used with the remaining data to investigate sensitivity of the near infrared spectroscopic measurement to physiologic changes resulting from cardiopulmonary bypass. Near infrared spectroscopic and reference pH and Po2 measurements were compared for each subject using standard error of prediction. Near infrared spectroscopic pH and Po2 at baseline were compared with values during cardiopulmonary bypass just before rewarming commenced (hypotensive, hypothermic), after rewarming (hypotensive, normothermic) just before discontinuation of cardiopulmonary bypass, and at 6 hrs following cardiopulmonary bypass (normotensive, normothermic) using mixed-model analysis of variance. Near infrared spectroscopic pH and Po2 were well correlated with the invasive measurement of pH (R2 =.84) and Po2 (R 2 =.66) with an average standard error of prediction of 0.022 +/- 0.008 pH units and 6 +/- 3 mm Hg, respectively. The average difference between the invasive and near infrared spectroscopic measurement was near zero for both the pH and Po2 measurements. Near infrared spectroscopic Po2 significantly decreased 50% on initiation of cardiopulmonary bypass and remained depressed throughout the bypass and monitored intensive care period. Near infrared spectroscopic pH decreased significantly during cardiopulmonary bypass, decreased significantly during rewarming, and remained depressed 6 hrs after cardiopulmonary bypass. Diabetic patients responded differently than nondiabetic subjects to cardiopulmonary bypass, with lower muscle pH values (p =.02). CONCLUSIONS: Near infrared spectroscopic-measured muscle pH and Po2 are sensitive to changes in tissue perfusion during cardiopulmonary bypass.
Non-NASA Center↗
Mid-Infrared Reflectance Imaging of Thermal-Barrier Coatings
An apparatus for mid-infrared reflectance imaging has been developed as means of inspecting for subsurface damage in thermal-barrier coatings (TBCs). The apparatus is designed, more specifically, for imaging the progression of buried delamination cracks in plasma-sprayed yttria-stabilized zirconia coatings on turbine-engine components. Progression of TBC delamination occurs by the formation of buried cracks that grow and then link together to produce eventual TBC spallation. The mid-infrared reflectance imaging system described here makes it possible to see delamination progression that is invisible to the unaided eye, and therefore give sufficiently advanced warning before delamination progression adversely affects engine performance and safety. The apparatus (see figure) includes a commercial mid-infrared camera that contains a liquid-nitrogen-cooled focal plane indium antimonide photodetector array, and imaging is restricted by a narrow bandpass centered at wavelength of 4 microns. This narrow wavelength range centered at 4 microns was chosen because (1) it enables avoidance of interfering absorptions by atmospheric OH and CO2 at 3 and 4.25 microns, respectively; and (2) the coating material exhibits maximum transparency in this wavelength range. Delamination contrast is produced in the midinfrared reflectance images because the introduction of cracks into the TBC creates an internal TBC/air-gap interface with a high diffuse reflectivity of 0.81, resulting in substantially higher reflectance of mid-infrared radiation in regions that contain buried delamination cracks. The camera is positioned a short distance (.12 cm) from the specimen. The mid-infrared illumination is generated by a 50-watt silicon carbide source positioned to the side of the mid-infrared camera, and the illumination is collimated and reflected onto the specimen by a 6.35-cm-diameter off-axis paraboloidal mirror. Because the collected images are of a steady-state reflected intensity (in contrast to the transient thermal response observed in infrared thermography), collection times can be lengthened to whatever extent needed to achieve desired signal-to-noise ratios. Each image is digitized, and the resulting data are processed in several steps to obtain a true mid-infrared reflectance image. The raw image includes thermal radiation emitted by the specimen in addition to the desired reflected radiation. The thermal-radiation contribution is eliminated by subtracting the image obtained with the illumination off from the image obtained with the illumination on. A flat-field correction is then made to remove the effects of non-uniformities in the illumination level and pixel-to-pixel variations in sensitivity. This correction is performed by normalizing to an image of a standard object that has a known reflectance at a wavelength of 4 microns. After correction, each pixel value is proportional to the reflectance (at a wavelength of 4-microns) at the corresponding location on the specimen. Mid-infrared reflectance imaging of specimens that were thermally cyc led for different numbers of cycles was performed and demonstrated t hat mid-infrared reflectance imaging was able to monitor the gradual delamination progression that occurs with continued thermal cycling . Reproducible values were obtained for the reflectance associated w ith an attached and fully delaminated TBC, so that intermediate refle ctance values could be interpreted to successfully predict the numbe r of thermal cycles to failure.
Edlridge, Jeffrey I.↗
The Cassini mission: Infrared and microwave spectroscopic measurements
The Cassini Orbiter and Titan Probe model payloads include a number of infrared and microwave instruments. This document describes: (1) the fundamental scientific objectives for Saturn and Titan which can be addressed by infrared and microwave instrumentation, (2) the instrument requirements and the accompanying instruments, and (3) the synergism resulting from the comprehensive coverage of the total infrared and microwave spectrum by the complement of individual instruments. The baseline consists of four instruments on the orbiter and two on the Titan probe. The orbiter infrared instruments are: (1) a microwave spectrometer and radiometer; (2) a far to mid-infrared spectrometer; (3) a pressure modulation gas correlation spectrometer, and (4) a near-infrared grating spectrometer. The two Titan probe infrared instruments are: (1) a near-infrared instrument, and (2) a tunable diode laser infrared absorption spectrometer and nephelometer.
Kunde, V. G.↗
Resonant infrared detector with substantially unit quantum efficiency
A resonant infrared detector includes an infrared-active layer which has first and second parallel faces and which absorbs radiation of a given wavelength. The detector also includes a first tuned reflective layer, disposed opposite the first face of the infrared-active layer, which reflects a specific portion of the radiation incident thereon and allows a specific portion of the incident radiation at the given wavelength to reach the infrared-active layer. A second reflective layer, disposed opposite the second face of the infrared-active layer, reflects back into the infrared-active layer substantially all of the radiation at the given wavelength which passes through the infrared-active layer. The reflective layers have the effect of increasing the quantum efficiency of the infrared detector relative to the quantum efficiency of the infrared-active layer alone.
Farhoomand, Jam↗
Infrared Astronomy with Arrays: The Next Generation; Sunset Village, Los Angeles, CA, Oct. 1993
Conference papers on infrared array techniques and methods for infrared astronomy are presented. Topics covered include the following: infrared telescopes; infrared spectrometers; spaceborne astronomy; astronomical observatories; infrared cameras; imaging techniques; sky surveys; infrared photography; infrared photometry; infrared spectroscopy; equipment specifications; data processing and analysis; control systems; cryogenic equipment; adaptive optics; image resolution; infrared detector materials; and focal plane arrays.
Mclean, Ian S.↗
Wide-Field Infrared Survey Telescope (WFIRST) Interim Report
The New Worlds, New Horizons (NWNH) in Astronomy and Astrophysics 2010 Decadal Survey prioritized the community consensus for ground-based and space-based observatories. Recognizing that many of the community s key questions could be answered with a wide-field infrared survey telescope in space, and that the decade would be one of budget austerity, WFIRST was top ranked in the large space mission category. In addition to the powerful new science that could be accomplished with a wide-field infrared telescope, the WFIRST mission was determined to be both technologically ready and only a small fraction of the cost of previous flagship missions, such as HST or JWST. In response to the top ranking by the community, NASA formed the WFIRST Science Definition Team (SDT) and Project Office. The SDT was charged with fleshing out the NWNH scientific requirements to a greater level of detail. NWNH evaluated the risk and cost of the JDEM-Omega mission design, as submitted by NASA, and stated that it should serve as the basis for the WFIRST mission. The SDT and Project Office were charged with developing a mission optimized for achieving the science goals laid out by the NWNH re-port. The SDT and Project Office opted to use the JDEM-Omega hardware configuration as an initial start-ing point for the hardware implementation. JDEM-Omega and WFIRST both have an infrared imager with a filter wheel, as well as counter-dispersed moderate resolution spectrometers. The primary advantage of space observations is being above the Earth's atmosphere, which absorbs, scatters, warps and emits light. Observing from above the atmosphere enables WFIRST to obtain precision infrared measurements of the shapes of galaxies for weak lensing, infrared light-curves of supernovae and exoplanet microlensing events with low systematic errors, and infrared measurements of the H hydrogen line to be cleanly detected in the 1<z<2 redshift range important for baryon acoustic oscillation (BAO) dark energy measurements. The Infrared Astronomical Satellite (IRAS), the Cosmic Background Explorer (COBE), Herschel, Spitzer, and Wide-field Infrared Sur-vey Explorer (WISE) are all space missions that have produced stunning new scientific advances by going to space to observe in the infrared. This interim report describes progress as of June 2011 on developing a requirements flowdown and an evaluation of scientific performance. An Interim Design Reference Mission (IDRM) configuration is presented that is based on the specifications of NWNH with some refinements to optimize the design in accordance with the new scientific requirements. Analysis of this WFIRST IDRM concept is in progress to ensure the capability of the observatory is compatible with the science requirements. The SDT and Project will continue to refine the mission concept over the coming year as design, analysis and simulation work are completed, resulting in the SDT s WFIRST Design Reference Mission (DRM) by the end of 2012.
Green, J.↗
CubeSat Infrared Atmospheric Sounder (CIRAS) NASA InVEST Technology Demonstration
Infrared sounders measure the upwelling radiation of the Earth in the Midwave Infrared (MWIR) and Longwave Infrared (LWIR) region of the spectrum with global daily coverage from space. The observed radiances are assimilated into weather forecast models and used to retrieve lower tropospheric temperature and water vapor for climate studies. There are several operational sounders today including the Atmospheric Infrared Sounder (AIRS) on Aqua, the Crosstrack Infrared Sounder (CrIS) on Suomi NPP and JPSS, and the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp spacecraft. The CubeSat Infrared Atmospheric Sounder (CIRAS) is a NASA In-flight Validation of Earth Science Technologies (InVEST) program to demonstrate three new instrument technologies in an imaging sounder configuration. The first is a 2D array of High Operating Temperature Barrier Infrared Detector (HOT-BIRD) material, selected for its high uniformity, low cost, low noise and higher operating temperatures than traditional materials. The detectors are hybridized to a commercial ROIC and commercial camera electronics. The second technology is a MWIR Grating Spectrometer (MGS) designed to provide imaging spectroscopy for atmospheric sounding in a CubeSat volume. The MGS employs an immersion grating or grism, has no moving parts, and is based on heritage spectrometers including the OCO-2. The third technology is a Black Silicon infrared blackbody calibration target. The Black Silicon offers very low reflectance over a broad spectral range on a flat surface and is more robust than carbon nanotubes. JPL will also develop the mechanical, electronic and thermal subsystems for the CIRAS payload. The spacecraft will be a commercially available CubeSat. The integrated system will be a complete 6U CubeSat capable of measuring temperature and water vapor profiles with good lower tropospheric sensitivity. The low cost of CIRAS enables multiple units to be flown to improve temporal coverage or measure 3D Atmospheric Motion Vector (AMV) winds. CIRAS will launch in 2019 and is only a technology demonstration. However, what we learn will benefit future instruments that support operational weather forecasting and climate studies.
Pagano, Thomas S.↗
New members of the infrared cluster in the Orion Molecular Cloud
Near-infrared high-resolution scans (3.5 arcsec) of the core of the Orion Molecular Cloud (no. 1) have revealed 26 sources. Eleven of these are identified with faint visible stars. The remainder are thought to be highly reddened stars embedded in the molecular cloud and include at least two of the previously known infrared cluster members. Comparison of the distribution of infrared and visible stars on the plane of the sky and in an infrared color-magnitude diagram shows that the obscured infrared sources form a separate cluster of stars. The newly discovered sources appear to fall into two categories: (1) optically identified stars probably on the front surface of the cloud and associated with the Trapezium cluster; and (2) unidentified infrared stars probably associated with the molecular cloud and the embedded infrared cluster. It is plausible that the newly discovered infrared sources in the OMC-1 region are stars less massive than the previously known members and younger than visible stars of similar mass in Orion Association.
Lonsdale, C. J.↗
Near-infrared observations of IRAS minisurvey galaxies
Near-infrared photometry was obtained for 82 galaxies from the Infrared Astronomy Satellite (IRAS) minisurvey, a sample of infrared selected galaxies. The near-infrared colors of these galaxies are similar to those of normal field spiral galaxies, but cover a larger range in J - H and H - K. There is evidence of a tighter correlation between the near and far infrared emission than exists between far-infrared and the visible emission. These results suggest that hot dust emission contributes to the 2.2 micron luminosity, and extinction by dust affects both the near-infrared colors and the visible luminosities. In addition, there is an indication that the far-infrared emission in many of the minisurvey galaxies is coming from a strong nuclear component.
Carico, D. P.↗
Near-infrared observations of IRAS minisurvey galaxies
Near infrared photometry at J, H, and K was obtained for 82 galaxies from the IRAS minisurvey. The near infrared colors of these galaxies cover a larger range in J-H and H-K than do normal field spiral galaxies, and evidence is presented of a tighter correlation between the near and far infrared emission in far infrared bright galaxies than exists between the far infrared and the visible emission. These results suggest the presence of dust in the far infrared bright galaxies, with hot dust emission contributing to the 2.2 micron emission, and extinction by dust affecting both the near infrared colors and the visible luminosities. In addition, there is some indication that the infrared emission in many of the minisurvey galaxies is coming from a strong nuclear component.
Carico, David P.↗
Near-infrared observations of IRAS minisurvey galaxies
Near-infrared photometry was obtained for 82 galaxies from the Infrared Astronomy Satellite (IRAS) minisurvey, a sample of infrared selected galaxies. The near-infrared colors of these galaxies are similar to those of normal field spiral galaxies, but cover a larger range in J - H and H - K. There is evidence of a tighter correlation between the near and far infrared emission than exists between far-infrared and the visible emission. These results suggest that hot dust emission contributes to the 2.2 micron luminosity, and extinction by dust affects both the near-infrared colors and the visible luminosities. In addition, there is an indication that the far-infrared emission in many of the minisurvey galaxies is coming from a strong nuclear component.
Carico, David P.↗
An infrared survey of Galactic supernova remnants
A survey of Galactic supernova remnants (SNRs) in the infrared has been completed. Flux densities or upper limits on the flux densities have been measured for 157 objects in each of the four broad bands surveyed by the Infrared Astronomical Satellite (IRAS). Nearly one-third of the known SNRs exhibit some evidence of infrared emission. Confusion with other Galactic sources is a serious problem. Contour maps and halftone images are presented for 51 SNRs which are probable infrared sources. Initial analysis indicates that both the infrared spectra or colors and the ratio of infrared to radio brightnesses can discriminate between the youngest SNRs and older SNRs. In general, however, SNRs cannot be distinguished from other Galactic sources solely on the basis of their infrared colors. No apparent relation is found between the infrared surface brightnesses and the diameters of SNRs.
Arendt, Richard G.↗
Evidence against a simple two-component model for the far-infrared emission from galaxies
Two of the first Infrared Astronomy Satellite (IRAS) results were that galaxies have a wide range of values for the ratio of 60 micron to 100 micron flux density (0.2 less than or equal to S sub 60/S sub 100 less than or equal to 1.0) and that this ratio is correlated with L sub fir, L sub b, L sub fir being the total far-infrared luminosity and L sub b being the luminosity at visible wavelengths (de Jong et al. 1984; Soifer et al. 1984). From these results arose the following simple model for the far-infrared emission from galaxies (de Jong et al. 1984), which has remained the standard model ever since. In this model, the far-infrared emission comes from two dust components: warm dust (T approx. equals 50 K) intermingled with, and heated by, young massive OB stars in molecular clouds and HII regions, and colder dust (T approx. equals 20 K) associated with the diffuse atomic hydrogen in the interstellar medium and heated by the general interstellar radiation field. As the number of young stars in a galaxy increases, S sub 60/S sub 100 increases, because there is a greater proportion of warm dust, and so does L sub fir/L sub b, because most of the radiation from the young stars is absorbed by the dust, leading to a swifter increase in far-infrared emission than in visible light. Although this model explains the basic IRAS results, it is inelegant. It uses two free parameters to fit two data (the 60 and 100 micron flux densities)-and there are now several observations that contradict it. Despite these major problems with the two-component model, it is not clear what should be put in its place. When considering possible models for the far-infrared emission from galaxies, the observational evidence for our own galaxy must be considered. Researchers suspect that the study by Boulanger and Perault (1988) of the far-infrared properties of the local interstellar medium may be particularly relevant. They showed that molecular clouds are leaky - that most of the light from OB stars in molecular clouds does not heat the dust in the clouds, but instead leaks out. The consequence of this is that that while most of the far-infrared emission from the solar neighborhood is from dust associated with diffuse HI, this dust is mostly heated by young stars.
Eales, Stephen A.↗
Infrared images of merging galaxies
Infrared imaging of interacting galaxies is especially interesting because their optical appearance is often so chaotic due to extinction by dust and emission from star formation regions, that it is impossible to locate the nuclei or determine the true stellar distribution. However, at near-infrared wavelengths extinction is considerably reduced, and most of the flux from galaxies originates from red giant stars that comprise the dominant stellar component by mass. Thus near infrared images offer the opportunity to study directly components of galactic structure which are otherwise inaccessible. Such images may ultimately provide the framework in which to understand the activity taking place in many of the mergers with high Infrared Astronomy Satellite (IRAS) luminosities. Infrared images have been useful in identifying double structures in the nuclei of interacting galaxies which have not even been hinted at by optical observations. A striking example of this is given by the K images of Arp 220. Graham et al. (1990) have used high resolution imaging to show that it has a double nucleus coincident with the radio sources in the middle of the dust lane. The results suggest that caution should be applied in the identification of optical bright spots as multiple nuclei in the absence of other evidence. They also illustrate the advantages of using infrared imaging to study the underlying structure in merging galaxies. The authors have begun a program to take near infrared images of galaxies which are believed to be mergers of disk galaxies because they have tidal tails and filaments. In many of these the merger is thought to have induced exceptionally luminous infrared emission (cf. Joseph and Wright 1985, Sanders et al. 1988). Although the optical images of the galaxies show spectacular dust lanes and filaments, the K images all have a very smooth distribution of light with an apparently single nucleus.
Wright, G. S.↗