Novae in the Magellanic Clouds

1979 ◽  
Vol 46 ◽  
pp. 96-101
Author(s):  
J.A. Graham

During the past several years, a systematic search for novae in the Magellanic Clouds has been carried out at Cerro Tololo Inter-American Observatory. The Curtis Schmidt telescope, on loan to CTIO from the University of Michigan is used to obtain plates every two weeks during the observing season. An objective prism is used on the telescope. This provides additional low-dispersion spectroscopic information when a nova is discovered. The plates cover an area of 5°x5°. One plate is sufficient to cover the Small Magellanic Cloud and four are taken of the Large Magellanic Cloud with an overlap so that the central bar is included on each plate. The methods used in the search have been described by Graham and Araya (1971). In the CTIO survey, 8 novae have been discovered in the Large Cloud but none in the Small Cloud. The survey was not carried out in 1974 or 1976. During 1974, one nova was discovered in the Small Cloud by MacConnell and Sanduleak (1974).

1991 ◽  
Vol 148 ◽  
pp. 15-23 ◽  
Author(s):  
B. E. Westerlund

A vast amount of observational data concerning the structure and kinematics of the Magellanic Clouds is now available. Many basic quantities (e.g. distances and geometry) are, however, not yet sufficiently well determined. Interactions between the Small Magellanic Cloud (SMC), the Large Magellanic Cloud (LMC) and our Galaxy have dominated the evolution of the Clouds, causing bursts of star formation which, together with stochastic self-propagating star formation, produced the observed structures. In the youngest generation in the LMC it is seen as an intricate pattern imitating a fragmented spiral structure. In the SMC much of the fragmentation is along the line of sight complicating the reconstruction of its history. The violent events in the past are also recognizable in complex velocity patterns which make the analysis of the kinematics of the Clouds difficult.


2014 ◽  
Vol 9 (S307) ◽  
pp. 414-419
Author(s):  
Dominik J. Bomans ◽  
Alexander Becker ◽  
Kerstin Weis

AbstractSurveys of the resolved stellar content of entire galaxies are the natural tool to study fast evolutionary phases of massive stars. Therefore we launched the Magellanic Clouds Massive Stars and Feedback Survey (MCSF) and periodically imaged for 3 years the entire Small and Large Magellanic Cloud in u, B, V, R, I and Hα, [Oiii], [Sii] using the twin telescope RoBoTT at the University Observatory of the Ruhr-University Bochum at Cerro Armazones, Chile. Observations with short exposure times are included to ensure brightest stars not to be saturated, yielding a full coverage in luminosity. With this unique dataset we can study the massive stellar populations up to MB ∼ −10 mag and their feedback. Upon completion a high quality photometric and spatially complete catalog of the Magellanic Clouds will be established which is be comparable (or even beyond) the quality of HST based photometry of nearby galaxies.


1995 ◽  
Vol 163 ◽  
pp. 406-410 ◽  
Author(s):  
P. Bartzakos ◽  
A.F.J. Moffat ◽  
V. S. Niemela

The Magellanic Clouds provide an ideal laboratory to study the properties of Wolf-Rayet stars. In particular, the 25 WC/WO stars that they contain are nearly all of the same sub-class (21 WC4, one WC5, one WC6 and one WO in the Large Magellanic Cloud; one WO in the Small Magellanic Cloud). This, along with their formation in the same isolated environment, suggests that the wind structure is similar in each star. Thus, a study of other characteristics, such as the effects of binary separation and period on binary wind collisions, can be undertaken with little concern for differing winds. Some 30 high-quality CCD spectra for each of the 25 stars were obtained during three observing missions in the past decade. Although the analysis is not yet complete, the sample clearly contains four large-amplitude WR+O binaries with periods ranging from two to seventeen days and possibly other long-period systems. This paper deals with the wind interaction of the star B22.


2011 ◽  
Vol 7 (S283) ◽  
pp. 227-234
Author(s):  
Warren A. Reid

AbstractThe Magellanic Clouds are close enough to the Milky Way to provide an excellent environment in which to study extragalactic PNe. Most of these PNe are bright enough to be spectroscopically observed and spatially resolved. With the latest high resolution detectors on today's large telescopes it is even possible to directly observe a large number of central stars. Magellanic Cloud (MC) PNe provide several astrophysical benefits including low overall extinction and a good sample size covering a large range of dynamic evolutionary timescales while the known distances provide a direct estimation of luminosity and physical dimensions. Multi-wavelength surveys are revealing intriguing differences between MC and Galactic PNe.Over the past 5 years there has been a substantial increase in the number of PNe discovered in the Large Magellanic Cloud (LMC) in particular. Deep surveys have allowed the faint end of the luminosity function to be investigated, finally providing a strong clue to its overall shape. In so doing, the surveys are approaching completeness, estimated at ~80% in the LMC (~120 deg2) and ~65% in the Small Magellanic Cloud (SMC) (~20 deg2).The number of galaxies comprising the Local Group (LG) and its outskirts has been growing steadily over the past 5 years and now numbers 48. Most of the 7 newly discovered galaxies are dwarf spheroidal (dSph) in structure and range from 7.6 to 755 kpc from the Milky Way. Nonetheless, there are no published searches for PNe in any of these galaxies to date. Apart from the LMC and Milky Way, the number of PN discoveries has been very modest and only one additional LG galaxy has been surveyed for PNe over the past 5 years. This paper provides the number of Local Group PNe currently known and estimates each galaxy's total PN population.


1991 ◽  
Vol 148 ◽  
pp. 415-420 ◽  
Author(s):  
R. S. Booth ◽  
Th. De Graauw

In this short review we describe recent new observations of millimetre transitions of molecules in selected regions of the Magellanic Clouds. The observations were made using the Swedish-ESO Submillimetre Telescope, SEST, (Booth et al. 1989), the relatively high resolution of which facilitates, for the first time, observations of individual giant molecular clouds in the Magellanic Clouds. We have mapped the distribution of the emission from the two lowest rotational transitions of 12CO and 13CO and hence have derived excitation conditions for the molecule. In addition, we have observed several well-known interstellar molecules in the same regions, thus doubling the number of known molecules in the Large Magellanic Cloud (LMC). The fact that all the observations have been made under controlled conditions with the same telescope enables a reasonable intercomparison of the molecular column densities. In particular, we are able to observe the relative abundances among the different isotopically substituted species of CO.


2018 ◽  
Vol 36 (3) ◽  
pp. 396-404
Author(s):  
G. Petrov ◽  
J. Davis ◽  
W. Schumaker ◽  
M. Vargas ◽  
V. Chvykov ◽  
...  

AbstractThe development of laser wakefield accelerators (LWFA) over the past several years has led to an interest in very compact sources of X-ray radiation – such as “table-top” free electron lasers. However, the use of conventional undulators using permanent magnets also implies system sizes which are large. In this work, we assess the possibilities for the use of novel mini-undulators in conjunction with a LWFA so that the dimensions of the undulator become comparable with the acceleration distances for LWFA experiments (i.e., centimeters). The use of a prototype undulator using laser machining of permanent magnets for this application is described and the emission characteristics and limitations of such a system are determined. Preliminary electron propagation and X-ray emission measurements are taken with a LWFA electron beam at the University of Michigan.


1998 ◽  
Vol 15 (1) ◽  
pp. 128-131 ◽  
Author(s):  
Miroslav D. Filipović ◽  
Paul A. Jones ◽  
Graeme L. White ◽  
Raymond F. Haynes

AbstractWe present a comparison between the latest Parkes radio surveys (Filipović et al. 1995, 1996, 1997) and Hα surveys of the Magellanic Clouds (Kennicutt & Hodge 1986). We have found 180 discrete sources in common for the Large Magellanic Cloud (LMC) and 40 in the field of the Small Magellanic Cloud (SMC). Most of these sources (95%) are HII regions and supernova remnants (SNRs). A comparison of the radio and Hα flux densities shows a very good correlation and we note that many of the Magellanic Clouds SNRs are embedded in HII regions.


1991 ◽  
Vol 148 ◽  
pp. 401-406 ◽  
Author(s):  
Klaas S. De Boer

General aspects of ISM studies using absorption line studies are given and available data are reviewed. Topics are: galactic foreground gas, individual fields in the Magellanic Clouds (MCs) and MC coronae. Overall investigations are discussed. It is demonstrated that the metals in the gas of the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) are a factor of 3 and 10, respectively, in abundance below solar levels. The depletion pattern in the LMC is similar to that of the Milky Way.


1999 ◽  
Vol 190 ◽  
pp. 377-378
Author(s):  
A. Moneti ◽  
R. J. Laureijs ◽  
J.M. van der Hulst ◽  
F. Israel ◽  
P.P. van der Werf

With the detection of strong PAH features and H2 emission in selected knots of the N159, N11A, and 30 Dor regions in the LMC, we present the first results of a study that is part of a coordinated Guaranteed Time ISO programme to investigate star formation in the Magellanic Clouds. The PAH features have different ratios than the ones in Galactic reflection nebulae.


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