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Classification and Identification of IRAS Sources with Low-Resolution Spectra
IRAS low-resolution spectra were extracted for 11,224 IRAS sources.These spectra were classified into astrophysical classes, based on thepresence of emission and absorption features and on the shape of thecontinuum. Counterparts of these IRAS sources in existing optical andinfrared catalogs are identified, and their optical spectral types arelisted if they are known. The correlations between thephotospheric/optical and circumstellar/infrared classification arediscussed.
| H_2_O maser emission from irregular variables.
We have performed a search for the 22 GHz water maser line among 72optically identified irregular and semiregular red variables. Newdetections were made of five stars, while only four of nine objectspreviously known as maser sources were redetected. The probability forthe detection of H_2_O maser emission increases with V light amplitude,and with H-K and K-[12] colours just as in regular Mira and semiregularvariables of SRa- and SRb-types. The detection rate of water masers isabout 25% for nearby Lb objects (D<400 pc) in the sample, comparableto that observed in the SRa and SRb stars. No masers were detected inobjects with mass loss rates <=4x10^-8^Msun_/yr. Maserluminosities are 10^41^-10^43^photons/s similar to that of the bluestMiras and typical SRa and SRb stars showing water maser emission. Acomparison of our data on irregular stars with those previously obtainedon SRa and SRb variables suggests that most radio and infraredproperties are indistinguishable among both classes of objects.
| The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars
The Henry Draper Extension Charts (HDEC), published in the form offinding charts, provide spectral classification for some 87000 starsmostly between 10th and 11th magnitude. This data, being highlyvaluable, as yet was practically unusable for modern computer-basedastronomy. An earlier pilot project (Roeser et al. 1991) demonstrated apossibility to convert this into a star catalogue, using measurements ofcartesian coordinates of stars on the charts and positions of theAstrographic Catalogue (AC) for subsequent identification. We presenthere a final HDEC catalogue comprising accurate positions, propermotions, magnitudes and spectral classes for 86933 stars of the HenryDraper Extension Charts.
| Supplement to the Arecibo 1612 MHz survey of color-selected IRAS sources
The completeness of the Arecibo 1612 MHz survey of color-selected IRASsources is extended to (25-12) micrometer greater than -0.7. In addition(1) most IR sources with spectral types normally associated with OH/IRstars and colors outside the coverage of the original survey have beenexamined; (2) most ambiguous observations during the survey have beenreobserved; (3) most single peaked sources have been reexamined, and 17found with second peaks. We report 39 new 1612 MHz detections, of which34 are original. These are also surveyed in the mainlines. Analysis ofthe complete flux-limited survey confirms the existence of a longitudesensitivity effect in the detection of sources, which reduces the totalnumber detected by approximately equals 4%. This analysis sets an upperlimit of 16% on the proportion of a color-selected sample that may beidentified with carbon stars and/or star-formation regions.
| IRAS catalogues and atlases - Atlas of low-resolution spectra
Plots of all 5425 spectra in the IRAS catalogue of low-resolutionspectra are presented. The catalogue contains the average spectra ofmost IRAS poiont sources with 12 micron flux densities above 10 Jy.
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