scholarly journals The galactic wake model of the Magellanic Stream

1979 ◽  
Vol 84 ◽  
pp. 575-576
Author(s):  
Joel N. Bregman
Keyword(s):  
Galactic Plane ◽  
Magellanic Clouds ◽  
Radial Velocities ◽  
Tidal Model ◽  
Interaction Models ◽  
Self Consistent ◽  
Wake Model ◽  
Pass Through ◽  
Consistent Treatment ◽  
Magellanic Stream

Tidal interaction models for the origin of the Magellanic Stream have been fairly successful in reproducing the radial velocities of the Stream (Lin and Lynden-Bell 1977, Davies and Wright 1977). However, no investigator has yet attained a self consistent treatment in which (1) the LMC and SMC are bound for at least 5×109 yr, (2) the passing Magellanic Clouds warp the galactic plane, and (3) the Stream velocities are reproduced (Fujimoto and Sofue 1977). Also, Mathewson, Schwarz, and Murray (1977) argue that their 21 cm observations are evidence against the tidal model. To avoid these problems, they suggest that the Magellanic Clouds pass through a hot coronal gas and produce vortices in their wake which radiatively cool to form the HI clouds comprising the Stream.

A Drag Dominated Model of the Magellanic Stream

1985 ◽  
Vol 6 (2) ◽  
pp. 195-198 ◽  
Author(s):  
Gerhardt R. Meurer ◽  
G. V. Bicknell ◽  
R. A. Gingold
Keyword(s):  
Magellanic Clouds ◽  
Radial Velocities ◽  
Tidal Model ◽  
Drag Forces ◽  
Wide Range ◽  
Magellanic Stream ◽  
Gaseous Halo ◽  
Gas Drag ◽  
Magellanic System

AbstractWe present here the best of a series of models of the Magellanic stream. The dominant force in these models is gas drag. Gaseous cloudlets are torn from the bridge between the Large and Small Magellanic Clouds as the Magellanic system passes through a hot gaseous halo about our galaxy. The cloudlets are then stretched apart from each other by tidal and drag forces to form the Magellanic stream. Our best model closely reproduces the position of the stream on the sky and the run of radial velocities along the Magellanic stream. The agreement is almost as good as the best purely tidal model. In our best model the Magellanic system is only loosely bound to our galaxy and is on the first encounter with it. This overcomes some of the problems with purely tidal models. Our series of models indicate that there is a wide range of parameters that will produce a reasonable stream under the forces of gas drag and gravity.

HI Profiles in the Bridge Region of the Megallanic Clouds

1986 ◽  
Vol 6 (4) ◽  
pp. 471-500 ◽  
Author(s):  
R. X. McGee ◽  
Lynette M. Newton
Keyword(s):  
Radial Velocity ◽  
High Sensitivity ◽  
Magellanic Clouds ◽  
Radial Velocities ◽  
Main Body ◽  
Gaussian Analysis ◽  
Magellanic Stream ◽  
Three Components

AbstractTwo hundred and seventeen HI profiles at positions approximately 1 ° apart in the bridge region between the Small and Large Magellanic Clouds have been observed with a 15’ arc beam. Diagrams of all the profiles, lists of column densities and average radial velocities are given, together with details of the extensive Gaussian analysis needed to account for the components.It is shown that the bridge region is most complex. (a) Two radial velocity groups, +214 and +238 km s-1, represent the actual HI bridge between the two galaxies, (b) Three other components, at mean radial velocities of +155, +177 and +195 km s-1 are seen to be integral parts of the SMC, stretching east to R. A. ~ 04h. (c) A further three components in groups at mean radial velocities +253, +272 and +293 km s-1 appear to be extensions of HI from the main body of the LMC.Nine sets of five closely spaced observations in the lower Magellanic Stream and in the bridge region at high sensitivity supply further information about the region.

scholarly journals The Magellanic Stream

1974 ◽  
Vol 60 ◽  
pp. 617-624
Author(s):  
D. S. Mathewson ◽  
M. N. Cleary ◽  
J. D. Murray
Keyword(s):  
Galactic Plane ◽  
Gravitational Interaction ◽  
Great Circle ◽  
Magellanic Clouds ◽  
The Other ◽  
Small Magellanic Cloud ◽  
Velocity Range ◽  
Sky Survey ◽  
The Galaxy ◽  
Magellanic Stream

A southern sky survey of Hiin the velocity range − 340 km s−1 to + 380 km s−1 has shown that a long filament of H iextends from the Small Magellanic Cloud (SMC) region down to the South Galactic Pole and connects with the long Hifilament discovered recently by Wannier and Wrixon (1972) and van Kuilenberg (1972). There is also some evidence that this continues on the other side of the Magellanic Clouds and crosses the galactic plane at l = 306°. This filament, which follows very closely a great circle over its entire 180° arc across the sky, is given the name ‘The Magellanic Stream’. It may have been produced by gravitational interaction between the SMC and the Galaxy during a close passage (20 kpc) of the SMC some 5 × 108 yr ago, although it is impossible to account for the observed radial velocities along the Stream unless some force other than gravity is invoked to act on the Stream as well.

scholarly journals The interacting Magellanic System

1991 ◽  
Vol 148 ◽  
pp. 447-452 ◽  
Author(s):  
S. R. Wayte
Keyword(s):  
Magellanic Clouds ◽  
Entire Length ◽  
Tidal Model ◽  
The Past ◽  
Multi Phase ◽  
Magellanic Stream ◽  
Insight Into ◽  
Magellanic System ◽  
Anomalous Velocity

The Magellanic System is viewed focusing on the global interactions in the System. These give insight into its history and structure. The past orbits of the Magellanic Clouds (MCs) are examined. A tidal encounter between the Large and Small Magellanic Clouds (LMC, SMC) has almost certainly occurred within the last 109 yrs. This hypothesis is supported by the observed structure of the Magellanic System, and so is accepted. The Magellanic Stream is an indirect result of the tidal encounter which is crucial to understanding the Magellanic System. It is a complex interacting gas feature, bifurcated along its entire length with many anomalous velocity H I clouds alongside. The possible models for the Magellanic Stream are examined and here I propose that its origin is due to the collision of a multi-phase halo with the vast region of gas between the LMC and the SMC. In this respect the polar subsystem around our Galaxy is seen to be particularly important. The popular tidal model for the origin of the Magellanic Stream fails to satisfy key observational features, and is thus rejected.

scholarly journals The Magellanic Stream

1974 ◽  
Vol 58 ◽  
pp. 367-374 ◽  
Author(s):  
D. S. Mathewson ◽  
M. N. Cleary ◽  
J. D. Murray
Keyword(s):  
Galactic Plane ◽  
Gravitational Interaction ◽  
Great Circle ◽  
Magellanic Clouds ◽  
The Other ◽  
Small Magellanic Cloud ◽  
Velocity Range ◽  
Sky Survey ◽  
The Galaxy ◽  
Magellanic Stream

A southern sky survey of H I in the velocity range — 340 km s−1 to +380 km s−1 has shown that a long filament of H I extends from the Small Magellanic Cloud (SMC) region down to the South Galactic Pole and connects with the long H I filament discovered recently by Wannier and Wrixon (1972) and van Kuilenburg (1972). There is also some evidence that the feature continues on the other side of the Magellanic Clouds and crosses the galactic plane at l = 306°. The whole filament, which follows very closely a great circle over its entire 180° length, is given the name ‘The Magellanic Stream’. It may have been produced by gravitational interaction between the SMC and the Galaxy during a close passage (20 kpc) of the SMC some 5 × 108 yr ago although it is impossible to account for the observed radial velocities along the Stream unless some force other than gravity is invoked to act on the Stream as well.

scholarly journals Models for the dynamical evolution of the Magellanic System

2008 ◽  
Vol 4 (S256) ◽  
pp. 105-116
Author(s):  
Kenji Bekki
Keyword(s):  
Galactic Halo ◽  
Dynamical Evolution ◽  
Magellanic Clouds ◽  
Young Stars ◽  
Proper Motions ◽  
Self Consistent ◽  
The Galaxy ◽  
Formation And Evolution ◽  
Magellanic Stream ◽  
Magellanic System

AbstractI discuss the following five selected topics on formation and evolution of the LMC and the SMC based on fully self-consistent chemodynamical simulations of the Magellanic Clouds (MCs): (1) formation of bifurcated gaseous structures and young stars in the Magellanic bridge (MB), (2) formation of the Magellanic stream (MS) due to the tidal interaction between the LMC, the SMC, and the Galaxy within the last 2 Gyrs, (3) origin of the observed kinematical differences between H i gas and stars in the SMC, (4) formation of stellar structures dependent on their ages and metallicities in the LMC, and (5) a new common halo model explaining both the latest HST ACS observations on the proper motions of the LMC and the SMC and the presence of the MS in the Galactic halo. I focus exclusively on the latest developments in numerical simulations on formation and evolution of the Magellanic system.

scholarly journals The Magellanic Stream and its Related Problems

1984 ◽  
Vol 108 ◽  
pp. 115-123 ◽  
Author(s):  
M. Fujimoto ◽  
T. Murai
Keyword(s):  
Radial Velocity ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Optical Observations ◽  
Dark Halo ◽  
Small Magellanic Cloud ◽  
Characteristic Structure ◽  
Tidal Model ◽  
Space Orientation ◽  
Magellanic Stream

A brief survey is made of recent 21-cm and optical observations of the Magellanic Stream(MS). The space orientation of the Magellanic Clouds is touched upon in relation to modelling the MS. After summarizing a variety of models for the MS, we show that if our Galaxy is massive with a huge dark halo, a tidal model is most suitable for reproducing its characteristic structure and high-negative radial velocity. Past orbits of the Large and the Small Magellanic Cloud (LMC and SMC) are determined uniquely for the last 2×109 yr, if we postulate that the LMC and SMC are bound together for 1010 yr: Highly-noncircular motion of the SMC around the LMC could give a clue to understand some peculiar features associated with the Magellanic Clouds.

scholarly journals The circumstellar environment of the B[e] star GG Car: an interferometric modeling

2014 ◽  
Vol 9 (S307) ◽  
pp. 291-292
Author(s):  
A. Domiciano de Souza ◽  
M. Borges Fernandes ◽  
A. C. Carciofi ◽  
O. Chesneau
Keyword(s):  
Binary System ◽  
Primary Component ◽  
Compact Ring ◽  
Hot Stars ◽  
Self Consistent ◽  
Grain Formation ◽  
Formation And Evolution ◽  
Circumstellar Environments ◽  
Consistent Treatment ◽  
Circumstellar Environment

AbstractThe research of stars with the B[e] phenomenon is still in its infancy, with several unanswered questions. Physically realistic models that treat the formation and evolution of their complex circumstellar environments are rare. The code HDUST (developed by A. C. Carciofi and J. Bjorkman) is one of the few existing codes that provides a self-consistent treatment of the radiative transfer in a gaseous and dusty circumstellar environment seen around B[e] supergiant stars. In this work we used the HDUST code to study the circumstellar medium of the binary system GG Car, where the primary component is probably an evolved B[e] supergiant. This system also presents a disk (probably circumbinary), which is responsible for the molecular and dusty signatures seen in GG Car spectra. We obtained VLTI/MIDI data on GG~Car at eight baselines, which allowed to spatially resolve the gaseous and dusty circumstellar environment. From the interferometric visibilities and SED modeling with HDUST, we confirm the presence of a compact ring, where the hot dust lies. We also show that large grains can reproduce the lack of structure in the SED and visibilities across the silicate band. We conclude the dust condensation site is much closer to the star than previously thought. This result provides stringent constraints on future theories of grain formation and growth around hot stars.

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