We report and interpret a new, 100 ks X-ray observation of the supernova remnant N103B obtained by the ASCA Observatory.

Our recently obtained HST WFPC2 images of N63A reveal shocked cloudlets in the SNR interior. The study of N63A helps us understand the structure and evolution of SNRs in a cloudy medium.

We analyze optical, radio and X-ray data from supernova remnants (SNRs) in the Large Magellanic Cloud (LMC) in order to make a systematic study of a full sample at a known distance. By this multiwavelength examination of SNRs from various progenitors and environments, we will build a comprehensive picture of the evolution of SNR structure and energetics.

We have made 12CO(J=1−0) observations of the LMC with NANTEN. We report the results of a comparison between CO clouds and SNRs in the LMC. Among the 35 known SNRs, only 10 are possibly associated with CO clouds. These 10 CO clouds and SNRs deserve follow-up studies for possible interactions. We present overlays of CO clouds on the optical images of some of these SNRs.

We have made 12CO(J=1−0) observations of the LMC with the NANTEN millimeter-wave telescope and identified about 100 distinct giant molecular clouds (GMCs). A detailed comparison of the GMCs with stellar clusters and a UV image is discussed.

We have been conducting a Fabry-Perot kinematic survey of ionized gas in the Magellanic Clouds in the Hα and [O III]λ5007 lines, using a 36-cm telescope at the European Southern Observatory. This poster presents our kinematic study of HII regions located at the northwestern parts of the LMC bar.

The interstellar medium of LMC2, a well studied supershell in the Large Magellanic Cloud, has been probed in UV and optical absorption lines. The data allow to derive the kinematics, abundances and depletions of gas clouds in this supershell. The relative gas-phase abundances of observed elements with respect to sulphur are useful to determine the origins of the supershell absorption-line clouds.

LMC2 was one of the first supergiant shells in the Large Magellanic Cloud (LMC) to be identified, based on the detection of long, curved Hα filaments extending over 900 pc (Goudis & Meaburn 1978). LMC 2 is located to the east of the active star formation region south of 30 Doradus. LMC 2 is a spectacular supergiant shell in the LMC, having the most coherent filamentary structure and the highest X-ray surface brightness. As shown in Fig. 1, the diffuse X-ray emission from LMC 2 is bounded by the Hα filaments in the north and east. A bright X-ray arc is seen in the southwest quadrant, extending from N 158 and N 159.

We present first results of our study of the interplay between the 106 K, 104 K, 102 K gas phases in the supergiant shell LMC 4.

The IRAS Vela shell was first seen as a ring of infrared emission in the IRAS maps of the Gum-Vela region coincident with the Gum Nebula. We have studied the kinematics of the molecular material (12CO) associated with the IRAS point sources and Southern Dark Clouds seen in this region and established the presence of a giant expanding shell of molecular gas. The estimated mass, size and expansion velocity of the shell lead us to conclude that it is the remnant of a GMC, in the process of disintegration through the influence of a central OB association. We conjecture that the IRAS Vela shell is a nearby example of a “super shell” in its early stages of evolution and as such is an ideal opportunity to study these objects now widely seen both in our Galaxy and in new observations of the Magellanic Clouds.

We present two views of the region around SN 1987A: a three-dimensional map of structure revealed by light echoes, and a multicomponent velocity map at 10 km s−1 resolution in [N II], correlating the various superbubble structures found in both, with implications for their age and dynamics, as well as the history of the SN progenitor.

We review all radio-continuum surveys of the Magellanic Clouds (MCs) and also present latest results from our new mosaic surveys.

We have searched for supernova remnants (SNRs) in the irregular galaxies IC 10 and NGC 4449 by means of Fabry-Perot interferometry in Hα and [SII] lines, complemented by radio continuum observations. We find several new SNR candidates in each galaxy in addition to the known ones. Although these galaxies have several common properties, the distributions of SNRs in each galaxy is different. This shows that the star formation mechanisms in these galaxies act in different ways, in favor of the formation of a large nebular HII complex in IC 10, similar to 30 Dor in the Large Magellanic Cloud. We are studying the conditions over which these different star formation histories take place.

Studies over the past decade have shown that the initial mass function (IMF) is the same for massive stars born in the OB associations of the LMC and SMC as in the associations of the Milky Way: the slope of the IMF is essentially Salpeter (Γ ~ −1.3), despite the factor of 4 difference in metallicity between these systems, and despite a factor of several hundred in stellar density between the sparsest and richest OB associations. However, there does appear to be a number of massive stars that are born in relative isolation, and the IMF of this mixed-age, field population is quite different than that of OB associations, with Γ ~ −4 in all three galaxies. The distribution of stars in the HR diagram is in excellent agreement with the Geneva group's evolutionary models for stars with masses with no “main-sequence widening problem” left to be solved. The massive stars born in clusters are formed quite coevally (Δτ < 1–2Myr), which allows us to use the “turn-off masses” to determine what mass objects become Wolf-Rayet stars of various types, and new results are briefly described. For the LMC, WNEs come from a wide range of masses, WCs come only from the highest mass stars, and Ofpe/WN9 “slash” stars come from lower mass OBs. Recent work on the R136a cluster (described in Hunter's review talk) suggest that there is no such thing as an upper mass cutoff to the IMF, at least not one that has been found observationally: for the youngest clusters (2 Myr and younger), the mass of the highest mass star present is simply dependent upon how populous the cluster is; i.e., the IMF is truncated by statistics, not physics.

We discuss the present status of knowledge for massive binary stars in the Magellanic Clouds. New data for known binaries, and radial velocity orbits for new binaries are reported.

More than 250 pointed observations of the Magellanic Clouds were performed with the ROSAT PSPC during its nominal operation phase. From an analysis of the images we obtained a list of about 750 point-like sources in the LMC and more than 500 sources in the SMC region. In combination with the ROSAT all-sky survey this large amount of data offers the unique opportunity to study the detailed physical properties of individual X-ray sources as well as the global statistical properties of different types of X-ray sources of a small galaxy as a whole. We report on the first results obtained from cross-correlations of our PSPC source catalogues with catalogues from other wavelength bands. Proper selection criteria, based on comparisons with known sources, permits the identification of new candidates for various source classes in the Magellanic Clouds such as supersoft sources, X-ray binaries and supernova remnants, and makes it possible to discriminate them from foreground stars and background objects.

The evolution of massive stars is far from being fully understood, as we outline by pointing to a number of open problems related to massive stars in the Magellanic Clouds. We argue that rotation may be a key ingredient in the physics of massive stars. We report on recent results obtained including rotation, and their relevance to these remaining questions.

Recent results from spectroscopic studies of Magellanic Cloud stars are discussed. Emphasis is placed on how to interpret CNO abundances to examine stellar evolution scenarios. Observed CNO abundances are best explained by the new rotating stellar evolution models (see Langer & Heger, these proceedings). In addition, the Rolleston et al. (these proceedings) abundances for B stars in the Magellanic Bridge are discussed.

Detailed abundances are measured in cool supergiants in Magellanic Cloud young populous clusters (NGC 330 in the SMC, NGC 2004, NGC 2100 and NGC 1818 in the LMC) and compared to those recently observed in samples of field supergiants in each Cloud. The analysis of the field supergiants shows no evidence of any abundance dispersion among the stars, compatible with a well mixed gas in these galaxies. However, previous determinations of the metallicity of NGC 330 and NGC 1818 give values well below the respective field values. This difference is investigated using a homogeneous method for the field and cluster samples, and the abundance ratios of various elements are examined.

Recent optical and infrared studies of 30 Doradus have revealed a more complex and diverse star-formation history than previously recognized. Five spatially and/or temporally distinct populations have been identified, including a new generation currently being triggered by the R136 cluster in its surroundings. HST/NICMOS observations of the latter provide insights into the phenomena of triggered massive-star formation, as well as the global structure and evolution of the starburst region.