We start from our six absolutely calibrated continuous stellar spectra from 1.2 to 35 ?m for K0, K1.5, K3, K5, and M0 giants. These were constructed as far as possible from actual observed spectral fragments taken from the ground, the Kuiper Airborne Observatory, and the IRAS Low Resolution Spectrometer, and all have a common calibration pedigree. From these we spawn 422 calibrated spectral templates for stars with spectral types in the ranges G9.5?K3.5 III and K4.5?M0.5 III. We normalize each template by photometry for the individual stars using published and/or newly secured near- and mid-infrared photometry obtained through fully characterized, absolutely calibrated, combinations of filter passband, detector radiance response, and mean terrestrial atmospheric transmission. These templates continue our ongoing effort to provide an all-sky network of absolutely calibrated, spectrally continuous, stellar standards for general infrared usage, all with a common, traceable calibration heritage. The wavelength coverage is ideal for calibration of many existing and proposed ground-based, airborne, and satellite sensors, particularly low- to moderate-resolution spectrometers. We analyze the statistics of probable uncertainties, in the normalization of these templates to actual photometry, that quantify the confidence with which we can assert that these templates truly represent the individual stars. Each calibrated template provides an angular diameter for that star. These radiometric angular diameters compare very favorably with those directly observed across the range from 1.6 to 21 mas.

Spectral Irradiance Calibration in the Infrared. X. A Self-Consistent Radiometric All-Sky Network of Absolutely Calibrated Stellar Spectra

The Midcourse Space Experiment (MSX) surveyed the entire Galactic plane within |b| ≤ 5° in four mid-infrared spectral bands between 6 and 25 μm at a spatial resolution of ~183. The survey was redundant within |b| ≤ 45 with four-fold coverage over two-thirds of the area. These survey data were combined to create 1680 15 × 15 images that cover the region with 6'' pixel spacing in each of the spectral bands. The images preserve the inherent resolution of the data but have up to twice the sensitivity of a single scan. The individual survey observations had to be extensively conditioned to achieve the co-add advantage. The noise equivalent radiance (NER) at 8.3 μm, the most sensitive MSX mid-infrared spectral band, varies from ~1.3 MJy sr-1 in the inner Galaxy to 3 times that at the latitude limits in the outer Galaxy; the sensitivities of the other MSX mid-infrared bands are 10–25 times less. Additionally, 36 lower resolution 10° × 10° images were generated in each band that span the full latitude and longitude range of the survey. These panoramic images have a resolution of ~12 with 36'' pixel spacing and a six-fold improvement in NER, making them an ideal product for comparison with radio surveys of the Galactic plane. An ancillary set of images has been created from other MSX astronomy experiments that lie within 10° of the Galactic plane. These images either extend the latitude coverage of the survey or provide deeper probes of Galactic structure either by themselves or when added to the survey images.

http://iopscience.iop.org/article/10.1086/320404/pdf

Midcourse Space Experiment Survey of the Galactic Plane

Recent observations by the Midcourse Space Experiment (MSX) have revealed the presence of compact objects seen in absorption against bright mid-infrared emission from the Galactic plane. Examination of MSX and IRAS images of these objects reveal that they are dark from 7 to 100 μm. We find ~2000 clouds in a 1° × 180° scan along the Galactic equator. The data suggest these objects are dense (n > 105 cm−3), cold (T<20 K) cores, without accompanying envelopes.

http://iopscience.iop.org/article/10.1086/311198/pdf

A Population of Cold Cores in the Galactic Plane

The SPIRIT III infrared telescope on the Midcourse Space Experiment (MSX) satellite has provided an unprecedented view of the mid-infrared emission (8-25 μm) of the Galactic plane. An initial analysis of images from MSX Galactic plane survey data reveals dark clouds seen in silhouette against the bright emission from the Galactic plane (Egan et al.). These clouds have mid-infrared extinctions in excess of 2 mag at 8 μm. We probed the physical properties of 10 of these MSX dark clouds using millimeter-wave molecular rotational lines as an indicator of dense molecular gas. All 10 clouds were detected in millimeter spectral lines of H2CO, which confirms the presence of dense gas. The distances to these clouds range from 1 to 8 kiloparsecs and their diameters from 0.4 to 15.0 pc. Excitation analysis of the observed lines indicates that the clouds are cold (T 105 cm-3]. Some of the clouds have nearby H II regions, H2O masers, and other tracers of star formation at comparable spectral line velocities; however, only one cloud contains embedded centimeter or infrared sources. The lack of mid- to far-infrared emission associated with these clouds suggests that they are not currently forming high-mass stars. If star formation is present in these clouds, it is clearly protostellar class 0 or earlier.

The Physical Properties of the Midcourse Space Experiment Galactic Infrared-dark Clouds

We explore the Magellanic Stream (MS) using a Gaussian decomposition of the H I velocity proles in the Leiden-Argentine-Bonn (LAB) all-sky H I survey. This decomposition exposes the MS to be composed of two laments distinct both spatially (as rst pointed out by Putman et al.) and in velocity. Using the velocity coherence of the laments, one can be traced back to its origin in what we identify as the SouthEast H I Overdensity (SEHO) of the Large Magellanic Cloud (LMC), which includes 30 Doradus. Parts of the Leading Arm (LA) can also be traced back to the SEHO in velocity and position. Therefore, at least one-half of the trailing Stream and most of the LA originates in the LMC, contrary to previous assertions that both the MS and the LA originate in the Small Magellanic Cloud (SMC) and/or in the Magellanic Bridge. The two MS laments show strong periodic, undulating spatial and velocity patterns that we speculate are an imprint of the LMC rotation curve. If true, then the drift rate of the Stream gas away from the Magellanic Clouds is 49 km s 1 and the age of the MS is 1.74 Gyr. The Staveley-Smith et al. high-resolution H I data of the LMC show gas outows from supergiant shells in the SEHO that seem to be creating the LA and LMC lament of the MS. Blowout of LMC gas is an eect not previously accounted for but one that probably plays an important role in creating the MS and LA. Subject headings: Galaxies: interactions { Galaxies: kinematics and dynamics { Galaxies: Local Group { Galaxy: halo { Intergalactic Medium { Magellanic Clouds { Radio Lines: general

http://iopscience.iop.org/article/10.1086/587042/pdf

The Origin of the Magellanic Stream and its Leading Arm

John D. Mill* Environmental Research Institute of Michigan, Arlington, Virginia 22209 Robert R. O'Neil* and Stephan Price* U.S. Air Force Phillips Laboratory, HanscomAFB, Massachusetts 01731 Gerald J. Romick and O. Manuel Uy Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland 20723 E. M. Gaposchkin** Massachusetts Institute of Technology, Lexington, Massachusetts 02173 Glenn C. Light The Aerospace Corporation, Los Angeles, California 90009-2970 W. Walding Moore Jr.** U.S. Army Space and Strategic Defense Command, Huntsville, Alabama 35807-3801 Thomas L. Murdock General Research Corporation, Danvers, Massachusetts 01923 and A. T. Stair Jr. Visidyne, Burlington, Massachusetts 01803

Midcourse Space Experiment: Introduction to the Spacecraft, Instruments, and Scientific Objectives

Infrared Investigations of Aurora and Airglow

The planned mid-course space experiment (MSX) observations will include two experiments for remote detection of atmospheric trace constituents above 10 km altitude, based on measurements of limb spectral radiance by the cryogenic IR interferometer and the ultraviolet and visible spectrographic imagers. The timing of the measurements is particularly advantageous since they will likely be the only regular limb observations of trace constituents during the operational lifetime of the MSX satellite. The SPIRIT III interferometer has a maximum spectral resolution of 1 cm-1 in six spectrally isolated channels whose vertical fields of view are between 4 and 13 km in line-of-sight tangent altitude. The six channels will provide spectra over wavelengths in the 2.6-28 micrometers range for tangent heights up to 180 km. The capabilities of the interferometer for the planned remote-sensing experiments, based on predicted instrument noise and saturation levels, are described in this paper.

Mid-course Space Experiment (MSX): capabilities of the LWIR interferometer for remote sensing of trace constituents in the stratosphere and mesosphere

[1] Spatial Infrared Imaging Telescope (SPIRIT) III radiometer on the Midcourse Space Experiment (MSX) satellite measured highly structured infrared, IR, emission from polar mesospheric cloud (PMC) ice particles at northern latitudes above 51 degrees on 22 July 1996 in the 11.1 to 13.2 and 18.2 to 25.1 μm radiometer channels, bands C and E, respectively. Measurements of the PMC thermal emissions included the observation of an extended cloud at 84.8°N and 325.6°E at 0313:25 UT, a local solar time of approximately 0056. In this Earth limb observation, the radiance due to the PMC has been isolated from other sources-atmospheric emission, nonrejected off axis radiation from the terrestrial surface and zodiacal radiance-and inverted to determine the volume emission rates of the ice particles at a spatial resolution of 0.3 km in the altitude range from 83.4 to 86.4 km. The band C PMC volume emission rate profile has a maximum value at 84.0 ± 0.3 km and decreases to one half the peak value at 85.0 and 83.5 km. Temperatures in the range from 143 ± 7 to 130 ± 8 K and ice volume densities from 1.5 to 0.5 × 10−13 cm3 per cm3 were determined from the LWIR volume emission rates at altitudes from 83.4 to 86.4 km. The PMC ice densities are equivalent to an enriched gas phase water mixing ratio of 8 to 16 parts per million by volume, ppmv, and a vertical column mass density of 3.3 × 10−8 gms cm−2 in this observation.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2007JA012858

A. T. Stair

Papers

Midcourse Space Experiment: Introduction to the Spacecraft, Instruments, and Scientific Objectives

Infrared Investigations of Aurora and Airglow

Mid-course Space Experiment (MSX): capabilities of the LWIR interferometer for remote sensing of trace constituents in the stratosphere and mesosphere

Polar mesospheric clouds: Infrared measurements from the Midcourse Space Experiment