|Radio Continuum Structure of the Orion Nebula|
We have imaged the large-scale radio continuum structure in the Orionregion with the Very Large Array at 330 MHz. Arcminute-resolutionmorphology of the extended emission in the H II regions M42 and M43 (NGC1976 and NGC 1982) and in the NGC 1973-75-77 nebulosity to the north arepresented. A low surface brightness thermal radio halo is detected inthe H II region M42: comparison with an optical photograph indicatesthat the radio emission distinguishes optical emission structures fromreflection nebulosities. In NGC 1977 we have discovered a compact,steep-spectrum radio source coincident with a bright optical rim.
|Exploring southern nebulae.|
|M is for Messier.|
|Deep-sky photography - TMax or Technical Pan?|
Baked Technical Pan 2415 film was compared with the new T-grainemulsions TMax 100, TMax 400 and TMax 3200 (untreated) in order toevaluate the effectiveness of the new materials for long exposuredeep-sky photography.
|The large system of molecular clouds in Orion and Monoceros|
Emission is noted over about one-eighth of an 850-sq deg region centeredon Orion and Monoceros that has been surveyed in the J = 1 to 0 line ofCO; most of the emission arises from giant molecular clouds associatedwith Orion A and B, and Mon R2. A much smaller area was surveyed forC-13O emission. A comparison of cloud masses obtained by threeindependent methods indicates that CO luminosity is as accurate ameasure of cloud mass as other indicators. The possible relationshipsamong clouds in the survey are discussed, including the conjecture thatthe overall Orion complex of clouds is a much larger system thanpreviously considered, incorporating most of the clouds in the presentsurvey.
|Studies of bright diffuse galactic nebulae with special regard to their spatial distribution.|