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Spitzer Survey of the Large Magellanic Cloud: Surveying the Agents of a Galaxy's Evolution (SAGE). I. Overview and Initial Results
We are performing a uniform and unbiased imaging survey of the LargeMagellanic Cloud (LMC; ~7deg×7deg) using theIRAC (3.6, 4.5, 5.8, and 8 μm) and MIPS (24, 70, and 160 μm)instruments on board the Spitzer Space Telescope in the Surveying theAgents of a Galaxy's Evolution (SAGE) survey, these agents being theinterstellar medium (ISM) and stars in the LMC. This paper provides anoverview of the SAGE Legacy project, including observing strategy, dataprocessing, and initial results. Three key science goals determined thecoverage and depth of the survey. The detection of diffuse ISM withcolumn densities >1.2×1021 H cm-2 permits detailed studies of dust processes in the ISM. SAGE'spoint-source sensitivity enables a complete census of newly formed starswith masses >3 Msolar that will determine the current starformation rate in the LMC. SAGE's detection of evolved stars withmass-loss rates >1×10-8 Msolaryr-1 will quantify the rate at which evolved stars injectmass into the ISM of the LMC. The observing strategy includes two epochsin 2005, separated by 3 months, that both mitigate instrumentalartifacts and constrain source variability. The SAGE data arenonproprietary. The data processing includes IRAC and MIPS pipelines anda database for mining the point-source catalogs, which will be releasedto the community in support of Spitzer proposal cycles 4 and 5. Wepresent initial results on the epoch 1 data for a region near N79 andN83. The MIPS 70 and 160 μm images of the diffuse dust emission ofthe N79/N83 region reveal a similar distribution to the gas emissions,especially the H I 21 cm emission. The measured point-source sensitivityfor the epoch 1 data is consistent with expectations for the survey. Thepoint-source counts are highest for the IRAC 3.6 μm band and decreasedramatically toward longer wavelengths, consistent with the fact thatstars dominate the point-source catalogs and the dusty objects detectedat the longer wavelengths are rare in comparison. The SAGE epoch 1point-source catalog has ~4×106 sources, and more areanticipated when the epoch 1 and 2 data are combined. Using Milky Way(MW) templates as a guide, we adopt a simplified point-sourceclassification to identify three candidate groups-stars without dust,dusty evolved stars, and young stellar objects-that offer a startingpoint for this work. We outline a strategy for identifying foreground MWstars, which may comprise as much as 18% of the source list, andbackground galaxies, which may comprise ~12% of the source list.
| A catalog of far-ultraviolet point sources detected with the fast FAUST Telescope on ATLAS-1
We list the photometric measurements of point sources made by the FarUltraviolet Space Telescope (FAUST) when it flew on the ATLAS-1 spaceshuttle mission. The list contains 4698 Galactic and extragalacticobjects detected in 22 wide-field images of the sky. At the locationssurveyed, this catalog reaches a limiting magnitude approximately afactor of 10 fainter than the previous UV all-sky survey, TDl. Thecatalog limit is approximately 1 x 10-14 ergs A sq cm/s,although it is not complete to this level. We list for each object theposition, FUV flux, the error in flux, and where possible anidentification from catalogs of nearby stars and galaxies. Thesecatalogs include the Michigan HD (MHD) and HD, SAO, the HIPPARCOS InputCatalog, the Position and Proper Motion Catalog, the TD1 Catalog, theMcCook and Sion Catalog of white dwarfs, and the RC3 Catalog ofGalaxies. We identify 2239 FAUST sources with objects in the stellarcatalogs and 172 with galaxies in the RC3 catalog. We estimate thenumber of sources with incorrect identifications to be less than 2%.
| Variability of luminous blue variables. I. Intermediate-band photometry
An extensive photometric dataset has been compiled for six Luminous BlueVariables (LBVs). The dataset comprises published and unpublishedmeasurements in the Stroemgren, Geneva and Walraven photometric systems.The measurements within each individual system are presented in auniform manner. Combining observations from these three photometricsystems, a V_J_ light curve has been constructed for each LBV.Examination of the light curves reveals variations on widely differentmagnitude and time scales.
| Longterm Photometry of Variables at ESO - Part Two - the Second Data Catalogue 1986-1990
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993A&AS..102...79S&db_key=AST
| Long-term photometry of variables at ESO. I - The first data catalogue (1982-1986)
This paper presents the catalog of photometric data in the Stromgrensystem obtained during the first four years (October 1982 - September1986) of the Long-Term Photometry of Variables (LTPV) program at ESO.The data are available in computer-readable form.
| Instrumental effects and the Stroemgren photometric system
The extent to which the use of different photometers can affect resultson stellar color indices was investigated by simultaneously observing asample of widely different stars with several uvby photometric systemsavailable at the ESO, La Silla, Chile. In one instance, the ESO 50-cmtelescope and the four-channel photometer at the Danish 50-cm telescopewere used simultaneously. The reductions were performed separately oneach data set, using a linear color transformation procedure. Theresults agree with theoretical investigations which showed thatsubstantial errors can arise from the nonconformity of passbands. It isemphasized that it is necessary to use separate color transformationsfor various stellar types and classes and for different interstellarreddenings.
| Discovery of an S-Doradus Type Outburst of an Of-Star at La-Silla
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Osservazione e dati astrometrici
| Costellazione: | Mensa |
| Ascensione retta: | 05h32m18.58s |
| Declinazione: | -72°49'57.3" |
| Magnitudine apparente: | 8.339 |
| Distanza: | 209.205 parsec |
| Moto proprio RA: | -14.7 |
| Moto proprio Dec: | 14.7 |
| B-T magnitude: | 8.496 |
| V-T magnitude: | 8.352 |
Cataloghi e designazioni:
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