Engineering topics
Publications and source records attributed to Werner, M. W..
We interpret the faint optical counterpart to the mid-infrared southern extension as being due to partial obscuration by the intervening disk of the host galaxy.
We have obtained array camera images of the Orion BN/KL infrared complex at nine wavelengths between 4.8 and 20 mue.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
We report ISO Long Wavelength Spectrometer (LWS) observations fo the Sbc(s) pec galaxy NGC 5713. We have obtained strong detections of the fine-structure forbidden transitions [C(sub ii)] 158(micro)m, [O(sub i)]63(micro)m, and [O(sub iii)] 88(micro)m, and significant upper limits for[N(sub ii)]122(micro)m, [O(sub iii)] 52(micro)m, and [N(sub iii)] 57(micro)m. We also detect the galaxy's dust continuum emission between 43 and 197 microns.
We combine the ISOPHOT 60(micro)m image of Tuffs, et al. (1996) and VLA radio continuum images at 6 and 20cm from the literature to study the 60(micro)m light distribution and its correlation with radio continuum within the disk of nearby spiral galaxy NGC6946, at an effective resolution of + - 52.
We analyze the new mid-infrared maps of NGC 6946 for variations in the color ratio fo the 7-to-15(micro)m emission. Our preliminary findings are that this mid-infrared color is remarkably constant between arms and inter-arm regions, and as a function of radius in the disk, excluding the nuclear region.
The nearby spiral galaxy NGC 6946 was observed with ISO-CAM in the mid-infrared, achieving 7inch resolution and sub-MJy sr(sup -1) sensitivity. Images taken with CAM filters LW2 (7(micro)m) and LW3 (15(micro)m) are analyzed to determine the morphology of this galaxy and understand beter the emission mechanisms.
We present observations of the [S III]19(micro)m, [O III]52 and 88(micro)m, and [N III]57(micro)m lines toward 18 compact and ultracompact (UC) H II regions. These data were combined with data from the literature and high-resolution radio continuum maps to construct detailed statistical equilibrium and ionization equilibrium models of 34 compact H II regions located at galactocentric distances (Dg)0-12kpc. Our models simultaneously fit the observed IR fine-structure lines and high-resolution radio continuum maps.
Hubble Space Telescope (HST) data taken of the IRAS source FSC 10214+4724 suggest that the object has been gravitationally lensed by a galaxy in the foreground and that this lensing may be magnifying the apparent brightness by roughly 100 times.
Observations of a distant object in space with the data being taken by the Hubble Space Telescope (HST) Wide Field Planetary Camera. Scientific examination and hypothesis related to this object which appears to be either an extremely luminous dust embedded quasar, or a representative of a new class of astronomical objects (a primeval galaxy).
Far-infrared fine-structuze lines of compact H II regions can provide reliable abundances throughout the Galactic plane. We present here our most recent results, which once analyzed, will help to constrain models of the abundance gradient in our galaxy.
Maps are presented for 10, 20, and 30 micrometers of the central 60' X 90' (RA X Dec) of the galaxy made at approximately 4' resolution with the MSFC bolometer array. The maps are the first to show the thermal emission from dust particles in both the ionized cavity and the neutral-gas ring with high sensitivity and an angular resolution as good as several arcsec.
The Space Infrared Telescope Facility, to be launched into a near-Earth heliocentric orbit in the year 2001, will open broad new vistas for the study, at infrared wavelengths, of the objects in the Solar System and planetary systems around other stars. This paper focuses on the study of Kuiper-belt comets and circumstellar planetary debris disks.
A new infrared camera (AIR Camera) has been developed at NASA - Ames Research Center for observations from ground-based telescopes. The heart of the camera is a Hughes 58 x 62 pixel Arsenic-doped Silicon detector array that has the spectral sensitivity range to allow observations in both the 10 and 20 micron atmospheric windows.
This paper describes the status of NASA's Space Infrared Telescope Facility (SIRTF) program. SIRTF will be a cryogenically cooled observatory for infrared astronomy from space and is planned for launch early in the next decade. We discuss a newly modified baseline SIRTF mission and review the state of the detector technology which will provide the heart of SIRTF's scientific advances.
We obtained IR (5-23 microns) spectra of five carbon-rich objects in transition from the asymptotic giant branch (AGB) to the planetary nebula stage of evolution. These spectra show a variety of IR emission features due to circumstellar materials. In particular, all sources show the 6.2 and '7.7' micron bands, commonly observed in PNs and ascribed to polycyclic aromatic hydrocarbon molecules (PAHs). Some transition nebulae also show a strong 6-9 micron plateau characteristic for larger PAH clusters (about 400 C-atoms). A new broad feature at about 8.8 microns is present in some sources. This feature is distinctly different from the 8.6-micron PAH feature. This 8.8-micron feature may be present in the spectra of C-rich giants as well, but is not evident in PN spectra. We suggest that large amorphous carbon grains are responsible for the 8.8-micron feature. The transition objects show large spectral variations from source to source. This contrasts with C-rich PNs, which all show very similar IR spectra dominated by PAHs. These spectral variations between transition objects of similar effective temperatures cannot be due to excitation variations but imply compositional variations of the dust. Moreover, this result suggests that circumstellar dust evolves during the transition phase from red giant to PN, perhaps as a result of grain-grain collisions and shattering in the fast winds.