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|A radio continuum study of the Magellanic Clouds. VIII. Discrete sources common to radio and infrared surveys of the Magellanic Clouds|
We compare Parkes Telescope radio surveys with the IRAS Infrared (IR)surveys of the Magellanic Clouds (MCs). We find 130 discrete sources incommon towards the Large Magellanic Cloud (LMC) with both radio and IRemission. These 130 sources are mainly H Ii regions (89) and supernovaremnants (21). For 12 of the sources we have no identification and eightare background objects. We find 38 sources in common for the SmallMagellanic Cloud (SMC). Most of these sources are intrinsic (31) to theSMC, five sources are previously known background galaxies and twosources remain ambiguous. A flux density comparison of the radio and IRsources shows very good correlation and we note that the strongestsources at both radio and IR frequencies are H Ii regions. From theradio-IR comparison we propose that some 40 new sources in the LMC and10 in the SMC are H Ii regions or SNRs. All these new sources are alsoidentified in optical surveys.
|A radio continuum study of the Magellanic Clouds. VII. Discrete radio sources in the Magellanic Clouds|
We present a study of discrete radio sources in the Magellanic Clouds(MCs) using the latest large-scale radio surveys made with the Parkesradio telescope between 1.4 and 8.55 GHz. These surveys achieved highersensitivity then previous surveys done with the Parkes telescope and sothe number of discrete radio sources detected towards the MCs hasincreased by factor of five. Also, we have obtained improved positions,flux densities and radio spectral indices for all of these sources. Atotal of 483 sources towards the Large Magellanic Cloud (LMC) and 224towards the Small Magellanic Cloud (SMC) have been detected at at leastone radio frequency. Most of the MC's sources have been classified inone of three groups: SNRs, H Ii regions or background sources accordingto classification criteria established here. In total, 209 discreteradio sources in the LMC and the 37 sources in the SMC are classifiedhere to be either H Ii regions or SNRs. We investigate their luminosityfunctions as well as the statistics of background sources behind theMCs. Also, we examine the distribution of SNRs and H Ii regions in theMCs. Tables 5 and 6 are only available electronically at the CDS via ftp184.108.40.206 or via http://cdsweb.u-strasbg.fr/Abstract.html
|Extinction of H II regions in the Large Magellanic Cloud|
The extinction properties of H II regions in the Large Magellanic Cloudare investigated using radio continuum data obtained from the MolongloObservatory Synthesis Telescope, digitized and calibrated H-alpha data,and published Balmer decrement measurements. The resultingextinction-color excess diagram suggests that (1) most H II regions inthe Magellanic Clouds have similar extinction properties to the Galacticones, (2) all imaginable gas/dust configurations are possible, and (3)the extinction of some highly reddened H II region cores originatesexternally in cocoon shells. The puzzle of different extinction-colorexcess ratios of Galactic and extragalactic H II regions is explained asbeing due to the different populations of observed samples rather thanany intrinsic differences. The extinction of the observed Galactic H IIregions produced by foreground dust overwhelms the internal extinction,while the situation in the observed extragalactic H II regions is justthe opposite.
|A radio continuum study of the Magellanic Clouds. IV. Catalogues of radio sources in the Large Magellanic Cloud at 1.40, 2.45, 4.75, 4.85 and 8.55 GHz.|
From observations with the Parkes radio telescope, we present cataloguesof radio sources in the Large Magellanic Cloud at four frequencies:1.40, 2.45, 4.75 and 8.55GHz, and an additional catalogue from a sourceanalysis of the Parkes-MIT-NRAO survey at 4.85GHz. A total of 469sources have been detected at least one of these frequencies, 132 ofwhich are reported here for the first time as radio sources.
|Results of the ESO / SEST Key Programme on Co/ in the Magellanic Clouds - Part One - a Survey of Co/ in the Large Magellanic Cloud and the Small Magellanic Cloud|
As the first part of the ESO-Swedish SEST Key Programme on CO in theMagellanic Clouds, we have observed ^12^CO J = 1-0 towards 92 positionsin the LMC and 42 positions in the SMC. In the SMC we searched foremission from H II regions, dark clouds and IRAS infrared sources. Thegenerally negative detection rate of non-IRAS sources in the SMC led toan LMC source selection based on the IRAS results. In both galaxies, COwas detected towards the majority of sources observed. We also observed^13^C0 J = 1-0 towards the brighter ^12^CO sources in the LMC (37) andSMC (9). Compared to the strength of CO lines observed in the Milky WayGalaxy with identical linear resolutions, velocity-integrated COemission is weaker by at least a factor of three in the LMC sources andan order of magnitude in the SMC sources. The mean velocity-integratedisotopic intensity ratio I_12_/I_13_ is 12.5 in the LMC and about 15 inthe SMC. Individual ratios range from 8.5 to 20. These isotopicintensity ratios are two to three times higher than those found inGalactic molecular clouds.
|Dust in emission nebulae of the LMC derived from photometric reddening of stars|
VBLUW photometric observations of stars in emission nebulae of the LMCare reported. The luminosities and extinctions of the stars are derived.Agreement is found between the average photometric extinctions of thenebulae and the extinctions derived from the Balmer line decrementmeasured by Caplan and Deharveng (1985 and 1986). The photometricextinctions are shown in the CO map of the LMC (Cohen et al., 1988).
|The nebular complexes of the large and small Magellanic Clouds|
Long exposures of the complexes of ionized hydrogen in both the LMC andSMC have been taken with the 48-in. SRC Schmidt camera through a H-alpha+ forbidden NII interference filter of 100-A bandwidth. These plates andidentifying charts are presented in a form in which little informationis lost. A catalog of many individual emission regions in both thesegalaxies is also compiled. The relationships between the nebulositiesand OB associations as well as between 21-cm neutral hydrogen emissionand continuum radio emission are discussed, and a number ofsupernova-remnant candidates are listed for further study.
|Catalogues of Hα-EMISSION Stars and Nebulae in the Magellanic Clouds.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1956ApJS....2..315H&db_key=AST
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