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A Uniform Database of 2.2-16.5 μm Spectra from the ISOCAM CVF Spectrometer
We present all ISOCAM circular variable filter (CVF) spectra that covermore than one-third of the 2.2-16.5 μm spectral range of theinstrument. The 364 spectra have been classified according to theclassification system of Kraemer et al., as modified by Hodge et al. toaccount for the shorter wavelength range. Prior to classification, thespectra were processed and recalibrated to create a uniform database.Aperture photometry was performed at each wavelength centered on thebrightest position in each image field and the various spectral segmentsmerged into a single spectrum. The aperture was the same for all scalesizes of the images. Since this procedure differs fundamentally fromthat used in the initial ISOCAM calibration, a recalibration of thespectral response of the instrument was required for the aperturephotometry. The recalibrated spectra and the software used to createthem are available to the community on-line via the ISO Data Archive.Several new groups were added to the KSPW system to describe spectrawith no counterparts in either the SWS or PHT-S databases: CA, E/SA,UE/SA, and SSA. The zodiacal dust cloud provides the most commonbackground continuum to the spectral features, visible in almost 40% ofthe processed sources. The most characteristic and ubiquitous spectralfeatures observed in the CVF spectral atlas are those of theunidentified infrared bands (UIR), which are typically attributed toultraviolet-excited fluorescence of large molecules containing aromatichydrocarbons. The UIR features commonly occur superimposed on thezodiacal background (18%) but can also appear in conjunction with otherspectral features, such as fine-structure emission lines or silicateabsorption. In at least 13 of the galaxies observed, the pattern of UIRemission features has been noticeably shifted to longer wavelengths.Based on observations with the Infrared Space Observatory, a EuropeanSpace Agency (ESA) project with instruments funded by ESA Member States(especially the Principal Investigator countries: France, Germany, theNetherlands, and the United Kingdom) and with the participation of theInstitute of Space and Astronautical Science (ISAS) and the NationalAeronautics and Space Administration (NASA).
| HII regions in M33. II - Radio continuum survey
A new WSRT survey of M33 in the continuum at 1.4 GHz is presented. Withan angular resolution of 25 x 49 arcsec HPBW and a rms noise of 0.2 mJyper beam area (at the field center), 112 radio sources with H-alphanebulosities have been identified. From a comparison of this survey dataand 5 GHz observations obtained with the VLA and WSRT, the spectralindices of 17 sources have been determined. Only three of these sourceshave nonthermal spectra. A compact source is discovered 1 arcmin southof the nucleus of M33. This source has a flat radio spectrum and noH-alpha counterpart. This source is either a heavily obscured compactHII region or, more likely, a source similar to the Crab Nebula.
| Evidence for Composition Gradients across the Disks of Spiral Galaxies
Abstract image available at:http://adsabs.harvard.edu/abs/1971ApJ...168..327S
| The Spectra of the Emission Nebulosities in Messier 33.
Abstract image available at:http://adsabs.harvard.edu/abs/1942ApJ....95...52A
| The Rotation of the Spiral Nebula Messier 33.
Abstract image available at:http://adsabs.harvard.edu/abs/1942ApJ....95....5M
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