scholarly journals The Cool Atomic Gas in the Large Magellanic Cloud

1999 ◽  
Vol 190 ◽  
pp. 112-113
Author(s):  
M. Marx-Zimmer ◽  
F. Zimmer ◽  
U. Herbstmeier ◽  
J. M. Dickey ◽  
L. Staveley-Smith
Keyword(s):  
Interstellar Medium ◽  
Absorption Line ◽  
Milky Way ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Raw Material ◽  
Line Survey ◽  
Cool Gas ◽  
Compact Array ◽  
Atomic Phase

Studying the cool atomic phase of the interstellar medium is of special significance as cool atomic clouds can become the raw material for star formation and so determine the evolution of the whole galaxy. The cool atomic interstellar medium of the Large Magellanic Cloud (LMC) seems to be quite different from that in the Milky Way. In three 21 cm absorption line surveys using the Australia Telescope Compact Array (ATCA) the physical properties of the cool atomic hydrogen in the LMC and the halo of the Magellanic Clouds have been studied. Here we present the results of the third HI absorption line survey. A detailed investigation of the cool HI has been done toward the supergiant shell LMC4, the surroundings of 30 Doradus and in the direction of the eastern steep HI boundary. The data have been compared with survey 2 (Dickey et al. 1994) to probe the cool gas fraction for these different regions of the LMC and to study the differences of the cool atomic phase of the LMC and that of the Milky Way.

scholarly journals The interstellar medium of the Magellanic Clouds from absorption lines

1991 ◽  
Vol 148 ◽  
pp. 401-406 ◽  
Author(s):  
Klaas S. De Boer
Keyword(s):  
Interstellar Medium ◽  
Absorption Line ◽  
Milky Way ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Absorption Lines ◽  
Small Magellanic Cloud ◽  
General Aspects

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.

scholarly journals The Absorption Line Systems of the Supershell LMC2 in the Large Magellanic Cloud

1999 ◽  
Vol 190 ◽  
pp. 154-155
Author(s):  
Adeline Caulet
Keyword(s):  
Optical Absorption ◽  
Interstellar Medium ◽  
Gas Phase ◽  
Absorption Line ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Absorption Lines

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.

scholarly journals Star-formation masers in the Magellanic Clouds: A multibeam survey with new detections and maser abundance estimates

2008 ◽  
Vol 4 (S256) ◽  
pp. 227-232
Author(s):  
J. A. Green ◽  
J. L. Caswell ◽  
G. A. Fuller ◽  
A. Avison ◽  
S. L. Breen ◽  
...  
Keyword(s):  
Excited State ◽  
Star Formation ◽  
Milky Way ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Star Forming ◽  
Abundance Estimates ◽  
Complete Survey ◽  
Compact Array

AbstractThe results of the first complete survey for 6668-MHz CH3OH and 6035-MHz excited-state OH masers in the Small and Large Magellanic Clouds are presented. A new 6668-MHz CH3OH maser in the Large Magellanic Cloud has been detected towards the star-forming region N 160a, together with a new 6035-MHz excited-state OH maser detected towards N 157a. We also re-observed the previously known 6668-MHz CH3OH masers and the single known 6035-MHz OH maser. Neither maser transition was detected above ~0.13 Jy in the Small Magellanic Cloud. All observations were initially made using the CH3OH Multibeam (MMB) survey receiver on the 64-m Parkes radio telescope as part of the overall MMB project. Accurate positions were measured with the Australia Telescope Compact Array (ATCA). In a comparison of the star formation maser populations in the Magellanic Clouds and our Galaxy, the LMC maser populations are demonstrated to be smaller than their Milky Way counterparts. CH3OH masers are under-abundant by a factor of ~50, whilst OH and H2O masers are a factor of ~10 less abundant than our Galaxy.

scholarly journals An HI Mosaic of the Large Magellanic Cloud

1997 ◽  
Vol 14 (1) ◽  
pp. 119-121 ◽  
Author(s):  
Sungeun Kim ◽  
K. C. Freeman ◽  
L. Staveley-Smith ◽  
R. J. Sault ◽  
M. J. Kesteven ◽  
...  
Keyword(s):  
Brightness Temperature ◽  
Neutral Hydrogen ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Compact Array

AbstractThe parameters of a new Australia Telescope Compact Array (ATCA) mosaic of the Large Magellanic Cloud (LMC) in the 21-cm line of neutral hydrogen are described. A preliminary peak-brightness-temperature image of the whole of the LMC, and a detailed image of the region around the supergiant shells LMC 4 and 5 is shown.

scholarly journals The HI Supergiant Shells in the Large Magellanic Cloud

1997 ◽  
Vol 166 ◽  
pp. 521-524
Author(s):  
S. Kim ◽  
L. Staveley-Smith ◽  
R.J. Sault ◽  
M.J. Kesteven ◽  
D. McConnell ◽  
...  
Keyword(s):  
Differential Rotation ◽  
Spiral Structure ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Aperture Synthesis ◽  
Wide Field ◽  
Combined Action ◽  
Compact Array

AbstractWe present the result of an HI aperture synthesis mosaic of the Large Magellanic cloud (LMC), made recently with the Australia Telescope Compact Array (ATCA). The resolution of the mosaiced images is l′.0 (15 pc, using a distance to the LMC of 50 kpc). In contrast to its appearance at other wavelengths, the LMC is remarkably symmetrical in HI on the largest scales, with the bulk of the HI residing in a disk of diameter 8.°4 (7.3 kpc). Outer spiral structure is clearly seen, though the features appear to be due to differential rotation, therefore transient in nature. On small to medium scales, the combined action of numerous shells and supershells dominate the structures and motions of the HI gas in the LMC. A good correlation is seen between supershells previously identified in Hα (e.g. Meaburn 1980) and HI structures. We compare the results with a new wide-field Hα image.

scholarly journals The UM/CTIO Magellanic Cloud Emission-line Survey

1999 ◽  
Vol 190 ◽  
pp. 28-31 ◽  
Author(s):  
R. Chris Smith ◽  
Keyword(s):  
Interstellar Medium ◽  
Emission Line ◽  
Supernova Remnants ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
H Ii Regions ◽  
Deep Imaging ◽  
Small Scales ◽  
Nearby Galaxies ◽  
Line Survey

The Magellanic Clouds are unique in providing sites to study the interstellar medium (ISM) and its components at all scales. To promote the pursuit of such studies, we have begun the Magellanic Cloud Emission-line Survey (MCELS), a deep imaging survey of both of these nearby galaxies in the emission of Hα, [S II], and [O III]. The emission-line images will be used in detailed optical and multiwavelength studies of H II regions, supernova remnants, planetary nebulae, superbubbles, and supergiant shells. Together with parallel surveys at other wavelengths, this survey will provide the foundation upon which to build a deeper understanding of the ISM in the Clouds and other galaxies, from small scales (~1 pc) all the way up to global scales. We present a sample of recent and current work using the MCELS dataset.

scholarly journals “2-D Frutti” Spectra of B Supergiants in the Milky Way and the LMC

1988 ◽  
Vol 132 ◽  
pp. 559-562
Author(s):  
Edward L. Fitzpatrick
Keyword(s):  
Milky Way ◽  
Photon Counting ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Image Tube ◽  
Blue Region ◽  
Pattern Noise ◽  
Fixed Pattern Noise ◽  
The Individual ◽  
Type Detector

Digital spectra of 7 B-type supergiants in the Milky Way and 15 B-type supergiants in the Large Magellanic Cloud (LMC) were obtained in December 1986 using the “2-D Frutti” detector (2-DF) and the Carnegie Image Tube Spectrograph on the 1-m telescope at the Cerro Tololo Inter-American Observatory. The 2-DF is a photon counting, 2-dimensional Shechtman-type detector, now available on both the 1-m and 4-m telescopes at CTIO. The detector/spectrograph configuration used for the December observing run yielded spectra covering the classical blue region, 3800-5000 Å, with a resolution of approximately 3 Å. The typical observing procedure was to obtain spectra for each star at several locations along the slit. The individual spectra were then averaged (to reduce the detector fixed pattern noise) resulting in S/N ratios of 50-60 in the 4300 Å region.

scholarly journals The 100 strongest radio point sources in the field of the Large Magellanic Cloud at 1.4 GHz

2009 ◽  
pp. 65-70 ◽  
Author(s):  
J.L. Payne ◽  
L.A. Tauber ◽  
M.D. Filipovic ◽  
E.J. Crawford ◽  
Horta de
Keyword(s):  
Spectral Index ◽  
Planetary Nebulae ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Point Sources ◽  
H Ii Regions ◽  
Short Spacing ◽  
Mosaic Image ◽  
Initial List ◽  
Compact Array

We present the 100 strongest 1.4 GHz point sources from a new mosaic image in the direction of the Large Magellanic Cloud (LMC). The observations making up the mosaic were made using Australia Telescope Compact Array (ATCA) over a ten year period and were combined with Parkes single dish data at 1.4 GHz to complete the image for short spacing. An initial list of co-identifications within 1000 at 0.843, 4.8 and 8.6 GHz consisted of 2682 sources. Elimination of extended objects and artifact noise allowed the creation of a refined list containing 1988 point sources. Most of these are presumed to be background objects seen through the LMC; a small portion may represent compact H ii regions, young SNRs and radio planetary nebulae. For the 1988 point sources we find a preliminary average spectral index (?) of -0.53 and present a 1.4 GHz image showing source location in the direction of the LMC.

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