scholarly journals A Low Resolution Hydrogen-line Survey of the Magellanic System. II. Interpretation of Results

1963 ◽  
Vol 16 (4) ◽  
pp. 570 ◽  
Author(s):  
JV Hindman ◽  
FJ Kerr ◽  
RX McGee

A low resolution (202) survey of the neutral hydrogen in the Magellanic Clouds has produced two important additions to our knowledge of the system. (1) A bridge of gas between the Small and Large Cloud has been mapped. (2) The Small Cloud profiles show double peaks over a wide area, suggesting the possibility of two substantially separate masses of gas.

1963 ◽  
Vol 16 (4) ◽  
pp. 552 ◽  
Author(s):  
JV Hindman ◽  
RX McGee ◽  
AWL Carter ◽  
ECJ Holmes ◽  
M Beard

A survey of neutral hydrogen in the Clouds of Magellan has been made using a digital recording system in conjunction with a multichannel receiver and a 21 ft aerial. The system has been developed for use with the 210 ft radio telescope of the Australian National Radio Astronomy Observatory at Parkes, N.S.W.


1995 ◽  
Vol 166 ◽  
pp. 273-282
Author(s):  
B.E. Westerlund

It is essential for our understanding of the evolution of the Magellanic System, comprising the Large and the Small Magellanic Cloud, the Intercloud or Bridge region and the Magellanic Stream, to know its motions in the past. The Clouds have a common envelope of neutral hydrogen; this indicates that they have been bound to each others for a long time. The Magellanic System moves in the gravitational potential of our Galaxy; it is exposed to ram pressure through its movement in the galactic halo. Both effects ought to be noticeable in their present structure and kinematics. It is generally assumed, but not definitely proven, that the Clouds have been bound to our Galaxy for at least the last 7 Gyr. Most models assume that the Clouds lead the Magellanic Stream. The interaction between the Clouds has influenced their structure and kinematics severely. The effects should be possible to trace in the motions of their stellar and gaseous components as pronounced disturbances. Recent astrometric contributions in this field show a great promise for the future if still higher accuracy can be achieved.


1966 ◽  
Vol 19 (3) ◽  
pp. 343 ◽  

The 21 cm hydrogen-line data from a survey of the Large Magellanic Oloud with a 14',5 aerial beam have been simplified into distributions of intensities and radial velocities at profile peaks. Fifty-two large HI complexes of mean diameter 575 pc, density I hydrogen atom per cm3, and mass 4 X 106M o have been delineated. The study of the correlation between optically visible Population I components, such as HII regions and supergiant OB stars, and the neutral hydrogen has been greatly extended.


1964 ◽  
Vol 17 (4) ◽  
pp. 515 ◽  
Author(s):  
RX McGee

A recent survey of the neutral hydrogen in the Large Magellanic Cloud with a 14'�5 beam and the 48�channel H�line receiver has afforded an opportunity to compare the radial velocities of a number of optical objects with the radial velocities of the hydrogen gas in their directions.


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).


2018 ◽  
Vol 14 (S344) ◽  
pp. 86-89
Author(s):  
Anna M. Jacyszyn-Dobrzeniecka ◽  

AbstractWe present a three-dimensional structure of the Magellanic System using over 9 000 Classical Cepheids and almost 23 000 RR Lyrae stars from the OGLE Collection of Variable Stars. Given the vast coverage of the OGLE-IV data and very high completeness of the sample, we were able to study the Magellanic System in great details.We very carefully studied the distribution of both types of pulsators in the Magellanic Bridge area. We show that there is no evident physical connection between the Clouds in RR Lyrae stars distribution. We only see the two extended structures overlapping. There are few classical Cepheids in the Magellanic Bridge area that seem to form a genuine connection between the Clouds. Their on-sky locations match very well young stars and neutral hydrogen density contours. We also present three-dimensional distribution of classical pulsators in both Magellanic Clouds.


1999 ◽  
Vol 190 ◽  
pp. 45-50 ◽  
Author(s):  
John M. Dickey ◽  
Monika Marx-Zimmer ◽  
Christian Düsterberg ◽  
Ulrich Mebold ◽  
Snezana Stanimirović ◽  
...  

Surveys of λ21-cm absorption in the Magellanic System show that the cool phase of the HI is less abundant in the SMC than in the Milky Way, and may be so also in the LMC. The typical cool cloud temperature is colder than in the Milky Way, 30 to 40 K rather than 60 to 75 K. The lower abundance of cool phase HI can be traced to the lower heavy element abundances in the Magellanic environment. The cooler cloud temperatures are somewhat mysterious.


1999 ◽  
Vol 190 ◽  
pp. 95-96
Author(s):  
D. H. Morgan ◽  
Q. A. Parker ◽  
S. Phillipps

A new Hα survey of the Magellanic Clouds which is being carried out on fine-grained Tech-Pan emulsion with the UK 1.2m Schmidt Telescope will have the best combination of depth and resolution of any that cover such a wide area in and around the Magellanic Clouds. Preliminary results show that the films will provide identifications of new emission-line stars and nebulae.


1999 ◽  
Vol 190 ◽  
pp. 28-31 ◽  
Author(s):  
R. Chris Smith ◽  

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.


1983 ◽  
Vol 100 ◽  
pp. 305-306
Author(s):  
Norbert Thonnard

Do elliptical and SO galaxies in which type I supernovae (SNI) were detected contain more gas than those without SNI detections? Thirteen E and SO galaxies in the Virgo and Pegasus I clusters, seven with SNI detections and six without, were mapped well beyond the optical image at the 21-cm neutral hydrogen line. No HI was detected. In Virgo, the upper limit to MMI/LB is between 0.0005 and 0.0024.


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