The Magellanic Stream: the Turbulent Wake of the Magellanic Clouds in the Halo of the Galaxy

1977 ◽  
Vol 3 (2) ◽  
pp. 133-136 ◽  
Author(s):  
D. S. Mathewson ◽  
M. P. Schwarz ◽  
J. D. Murray
Keyword(s):  
Southern Hemisphere ◽  
Radio Telescope ◽  
Turbulent Wake ◽  
Magellanic Clouds ◽  
Total Length ◽  
The Galaxy ◽  
The One ◽  
Magellanic Stream ◽  
First Time ◽  
Made In

New observations of the Magellanic Stream were made in December 1976 with the 64-m radio telescope at the Parkes Observatory of CSIRO. The ridges of H I emission of the Stream were traced from near its tip at ℓ = 90°, b = -40° to the Magellanic Clouds. This was the first time that the total length of the Stream was observed with the one system (only possible from the southern hemisphere) and with high spatial (15’ of arc) and velocity (4 km s-1) resolution. The results of this survey are presented in Figures 1 and 2 and the main features are listed below.

scholarly journals Review of N-Body Models of Tidal Interactions

1999 ◽  
Vol 190 ◽  
pp. 480-486
Author(s):  
L. T. Gardiner
Keyword(s):  
Star Formation ◽  
Triple System ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Magellanic Clouds ◽  
Considerable Progress ◽  
Tidal Interactions ◽  
The Galaxy ◽  
Magellanic Stream ◽  
Made In

Considerable progress has been made in the current decade with the help of N-body simulations towards a deeper understanding of the nature of the dynamical relationship between the Large and Small Magellanic Clouds and the Galaxy. The origin of such features as the Magellanic Stream, the inter-Cloud Bridge, the Wing and large extension in depth of the SMC has come to be interpreted in the context of the tidal interactions among the members of the LMC-SMC-Galaxy triple system. The inclusion of gas-dynamical effects and star formation in the latest models has added further refinements to this picture and confirmed the enhancement of the star formation rate in the SMC as a result of the recent LMC-SMC encounter.

The Magellanic stream - The turbulent wake of the Magellanic clouds in the halo of the Galaxy

1977 ◽  
Vol 217 ◽  
pp. L5 ◽  
Author(s):  
D. S. Mathewson ◽  
M. P. Schwarz ◽  
J. D. Murray
Keyword(s):  
Turbulent Wake ◽  
Magellanic Clouds ◽  
The Galaxy ◽  
Magellanic Stream

scholarly journals Geographical vocabulary of the Shilan dialect of the Erzya-Mordovian language

2020 ◽  
Vol 12 (4) ◽  
pp. 358-367
Author(s):  
Nikolai V. Belenov
Keyword(s):  
Original Composition ◽  
Research Methods ◽  
Field Studies ◽  
The Other ◽  
Volga Region ◽  
The One ◽  
Xix Century ◽  
First Time ◽  
Source Materials ◽  
Made In

Introduction. The article presents the results of research of the geographical vocabulary of the Shilan dialect, one of the Erzya-Mordovian dialects of the Samara region, common among Erzya population of Shilan village in Krasnoyarsk region. The dialect belongs to rare Mordovian dialects of the Samara Volga region that were formed in the region since the middle of the XIX century, and therefore its research is of extra interest. Materials and Methods. The research methods are determined by the purpose and objectives of the study. The analysis of the geographical vocabulary of the Shilan dialect is carried out with the involvement of relevant items made in other Mordovian dialects of Samara region, adjacent territories of neighboring regions, as well as other territories of settlement of the Mordovians. Data on geographical vocabulary of the dialect introduced into research for the first time. The main source materials for the article is based on field studies in Silane village during the field seasons in 2017 and 2020, as well as in other Erzya-Mordovian and Moksha-Mordovian villages of Samara region and adjacent territories in 2015 – 2020. Results and Discussion. The study showed that the geographical vocabulary of the Shilan dialect of the Erzya-Mordovian language is significantly different from the corresponding lexical clusters in other dialects of the Mordovian region, which can be explained by natural geographical conditions surrounding Shilan village and the original composition of this lexical cluster of Erzya immigrants who founded this village. Conclusion. The analysis of the geographical vocabulary of the Shilan dialect allowed, on the one hand, to identify specific features of this cluster that distinguish it from the corresponding materials of other Mordovian dialects of the region, and, on the other hand, to identify common isoglosses between it and a number of the Erzya-Mordovian dialects of the Samara Volga region.

scholarly journals Cepheids in the Nearby Galaxy IC 1613

2000 ◽  
Vol 176 ◽  
pp. 157-160
Author(s):  
E. Antonello ◽  
L. Mantegazza ◽  
D. Fugazza ◽  
M. Bossi ◽  
S. Covino
Keyword(s):  
Magellanic Clouds ◽  
Light Curves ◽  
Nearby Galaxy ◽  
Short Discussion ◽  
The Galaxy ◽  
First Results ◽  
First Time

AbstractA summary of the first results of a search for Cepheids in IC 1613 is reported along with a short discussion of the adopted technique, a comparison of the characteristics of Cepheid light curves in the Galaxy, Magellanic Clouds and IC 1613, and a possible application for a P–L relation derivation. First overtone Cepheids have been identified for the first time in a galaxy farther than the Magellanic Clouds.

scholarly journals The Magellanic System: the puzzle of the leading gas stream

2019 ◽  
Vol 488 (1) ◽  
pp. 918-938 ◽  
Author(s):  
Thor Tepper-García ◽  
Joss Bland-Hawthorn ◽  
Marcel S Pawlowski ◽  
Tobias K Fritz
Keyword(s):  
Hydrodynamic Interaction ◽  
The Galaxy ◽  
Galactic Model ◽  
Coronal Density ◽  
Coronal Rotation ◽  
Cool Gas ◽  
Hot Corona ◽  
Magellanic Stream ◽  
First Time ◽  
Gas Bearing

ABSTRACT The Magellanic Clouds (MCs) are the most massive gas-bearing systems falling into the Galaxy at the present epoch. They show clear signs of interaction, manifested in particular by the Magellanic Stream, a spectacular gaseous wake that trails from the MCs extending more than 150° across the sky. Ahead of the MCs is the ‘Leading Arm’ usually interpreted as the tidal counterpart of the Magellanic Stream, an assumption we now call into question. We revisit the formation of these gaseous structures in a first-infall scenario, including for the first time a Galactic model with a weakly magnetized, spinning hot corona. In agreement with previous studies, we recover the location and the extension of the Stream on the sky. In contrast, we find that the formation of the Leading Arm – that is otherwise present in models without a corona – is inhibited by the hydrodynamic interaction with the hot component. These results hold with or without coronal rotation or a weak, ambient magnetic field. Since the existence of the hot corona is well established, we are led to two possible interpretations: (i) the Leading Arm survives because the coronal density beyond 20 kpc is a factor ≳10 lower than required by conventional spheroidal coronal X-ray models, in line with recent claims of rapid coronal rotation; or (ii) the ‘Leading Arm’ is cool gas trailing from a frontrunner, a satellite moving ahead of the MCs, consistent with its higher metallicity compared to the trailing stream. Both scenarios raise issues that we discuss.

scholarly journals How to Model the Chemical Evolution of Galaxies

1993 ◽  
Vol 155 ◽  
pp. 557-566
Author(s):  
Joachim Köppen
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Time Scale ◽  
Life Time ◽  
Magellanic Clouds ◽  
Formation Time ◽  
List Type ◽  
The Galaxy ◽  
H Ii Region ◽  
Magellanic Stream

For a first interpretation of the comparison of observational data, the crude “Simple Model” of chemical evolution is quite useful. Since it has well been described in the literature (e.g. Pagel and Patchett 1975, Tinsley 1980), let us here just review the assumptions and whether they are satisfied: 1.The galaxy is a closed system, with no exchange of matter with its surroundings: For the solar neighbourhood this probably is not true (the infamous Gdwarf-“problem”, Pagel 1989b). For the Magellanic Clouds this is most certainly wrong, because of the presence of the Inter-Cloud Region and the Magellanic Stream, and evidence for interaction with each other and the Galaxy as well (cf. e.g. Westerlund 1990).2.It initially consists entirely of gas (without loss of generality of primordial composition): This is good approximation also for models with gas infall, as long as the infall occurs with a time scale shorter than the star formation time scale.3.The metal production of the average stellar generation (the yield y) is constant with time: Initially, it is reasonable to make this assumption. For tables of the oxygen yield see Koppen and Arimoto (1991).4.The metal rich gas ejected by the stars is completely mixed with the ambient gas. To neglect the finite stellar life times (“instantaneous recycling approximation”) is appropriate for elements synthesized in stars whose life time is much shorter than the star formation time scale, such as oxygen, neon, sulphur, and argon.5.The gas is well mixed at all times: We don't know. The dispersion of H II region abundances may give an indication. In the Magellanic Clouds Dufour (1984) finds quite a low value (±0.08 dex for oyxgen).

scholarly journals Michigan 160: a precursor to the LMC?

1991 ◽  
Vol 148 ◽  
pp. 376-377
Author(s):  
L. Staveley-Smith
Keyword(s):  
Star Formation ◽  
Dynamical Evolution ◽  
Stellar Populations ◽  
Detailed Comparison ◽  
Elliptical Galaxies ◽  
Magellanic Clouds ◽  
Formation Processes ◽  
Stellar Formation ◽  
The Galaxy ◽  
Magellanic Stream

The tidal interaction between the Magellanic Clouds and the Galaxy is an important factor in influencing the physical and dynamical evolution of the Clouds (e.g. the Magellanic Stream) as well as the genesis and evolution of their respective stellar populations. However, how important is the influence of the Galaxy? This is a key question since we know that relatively isolated, magellanic-type galaxies do exist (e.g. NGC 3109 and NGC 4449) and have been just as efficient at star-formation as the LMC. It is possible in fact that the star formation in the clouds is primarily stochastic in nature and is relatively insensitive to the global forces which seem to have shaped stellar formation processes in massive spiral and elliptical galaxies. Unsupported by a massive bulge or halo component, cold gas disks are inherently susceptible to radial and bar-like instabilities (Efstathiou et al. 1982) which are very efficient at creating the dynamical pressures required for rapid star-formation. With this in mind, a detailed comparison of 'field' magellanic-type galaxies with the LMC and SMC is of some importance.

Preliminary Results Obtained with an Aperture Synthesis Telescope at 30 MHz

1972 ◽  
Vol 2 (2) ◽  
pp. 115-117 ◽  
Author(s):  
E. A. Finlay ◽  
B. B. Jones
Keyword(s):  
High Resolution ◽  
Southern Hemisphere ◽  
Radio Telescope ◽  
Hii Regions ◽  
Preliminary Results ◽  
Sky Survey ◽  
The Galaxy ◽  
Background Temperature ◽  
Two Temperatures ◽  
Galactic Background

A 30 MHz radio telescope has recently been completed at Fleurs, N.S.W. There has been a need for a high resolution sky survey to be carried out in the Southern Hemisphere at a frequency intermediate between 19.7 MHz (Shain et al.) and 85.7 MHz (Mills et al). One particular reason lies in the fact that some HII regions which are seen in absorption against the galactic background at 19.7 MHz and in emission at 85.7 MHz may match the background temperature at 30 MHz. If the temperature of such a region has been found by other means, the 30 MHz temperature of the portion of the Galaxy beyond it is determined irrespective of conditions nearer the observer, since the two temperatures must be equal.

scholarly journals The Magellanic System's Interactive Formations

2000 ◽  
Vol 17 (1) ◽  
pp. 1-5 ◽  
Author(s):  
M. E. Putman
Keyword(s):  
Velocity Distribution ◽  
High Velocity ◽  
Magellanic Clouds ◽  
Limiting Factors ◽  
Full Extent ◽  
Sky Survey ◽  
The Galaxy ◽  
Magellanic Stream ◽  
Shed Light

AbstractThe interaction between the Galaxy and the Magellanic Clouds has resulted in several high-velocity complexes which are connected to the Clouds. The complexes are known as the Magellanic Bridge, an HI connection between the Large and Small Magellanic Clouds, the Magellanic Stream, a 10° × 100° HI filament which trails the Clouds, and the Leading Arm, a diffuse HI filament which leads the Clouds. The mechanism responsible for these features formation remains under some debate, with the lack of detailed HI observations being one of the limiting factors in resolving the issue. Here I present several large mosaics of HI Parkes All-Sky Survey (HIPASS) data which show the full extent of the three Magellanic complexes at almost twice the resolution of previous observations. These interactive features are connected, but unique in their spatial and velocity distribution. The differences may shed light on their origin and present environment. Dense clumps of HI along the sightline to the Sculptor Group, which may or may not be associated with the Magellanic complexes, are also discussed.

scholarly journals The disruption of the Magellanic Stream

2008 ◽  
Vol 4 (S256) ◽  
pp. 122-128
Author(s):  
J. Bland-Hawthorn
Keyword(s):  
Magellanic Clouds ◽  
Ionized Gas ◽  
Present Evidence ◽  
Constant Rate ◽  
Diffuse Ionized Gas ◽  
The Galaxy ◽  
Hα Emission ◽  
Gas Accretion ◽  
Halo Gas ◽  
Magellanic Stream

AbstractWe present evidence that the accretion of warm gas onto the Galaxy today is at least as important as cold gas accretion. For more than a decade, the source of the bright Hα emission (up to 750 mR†) along the Magellanic Stream has remained a mystery. We present a hydrodynamical model that explains the known properties of the Hα emission and provides new insights on the lifetime of the Stream clouds. The upstream clouds are gradually disrupted due to their interaction with the hot halo gas. The clouds that follow plough into gas ablated from the upstream clouds, leading to shock ionisation at the leading edges of the downstream clouds. Since the following clouds also experience ablation, and weaker Hα (100–200 mR) is quite extensive, a disruptive cascade must be operating along much of the Stream. In order to light up much of the Stream as observed, it must have a small angle of attack (≈ 20°) to the halo, and this may already find support in new H i observations. Another prediction is that the Balmer ratio (Hα/Hβ) will be substantially enhanced due to the slow shock; this will soon be tested by upcoming WHAM observations in Chile. We find that the clouds are evolving on timescales of 100–200 Myr, such that the Stream must be replenished by the Magellanic Clouds at a fairly constant rate (≳ 0.1 M⊙ yr−1). The ablated material falls onto the Galaxy as a warm drizzle; diffuse ionized gas at 104 K is an important constituent of galactic accretion. The observed Hα emission provides a new constraint on the rate of disruption of the Stream and, consequently, the infall rate of metal-poor gas onto the Galaxy. When the ionized component of the infalling gas is accounted for, the rate of gas accretion is ≳ 0.4 M⊙ yr−1, roughly twice the rate deduced from H i observations alone.

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