scholarly journals A Sky Survey of Neutral Hydrogen at l 21 cm. II. The Detailed Distribution of Low Velocity Gas

1963 ◽  
Vol 16 (1) ◽  
pp. 136 ◽  
Author(s):  
RX McGee ◽  
JD Murray ◽  
Janice A Milton
Keyword(s):  
Radial Velocity ◽  
Line Profile ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
Hydrogen Line ◽  
Low Velocity ◽  
Sky Survey

The distributions of intensity and radial velocity of neutral hydrogen gas of low radial velocity are presented in the form of detailed diagrams of T max., the temperature at the peak of a hydrogen line profile, and of the radial velocity value at the Tmax .

scholarly journals Neutral Hydrogen Gas in the Taurus?Orion Region Observed with a Multichannel 21 cm Line Receiver

1959 ◽  
Vol 12 (2) ◽  
pp. 127 ◽  
Author(s):  
RX McGee ◽  
JD Murray
Keyword(s):  
Line Profile ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
Hydrogen Line ◽  
Short Time

A multichannel 21 cm hydrogen line receiver has been developed which is capable of producing a complete line profile in the very short time of 2 min.

scholarly journals A Sky Survey of Neutral Hydrogen at l 21 cm. III. Gas at Higher Radial Velocities

1964 ◽  
Vol 17 (1) ◽  
pp. 128 ◽  
Author(s):  
RX McGee ◽  
Janice A Milton
Keyword(s):  
Radial Velocity ◽  
Atomic Hydrogen ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
Radial Velocities ◽  
Channel Spacing ◽  
Sky Survey ◽  
Half Power

Information is presented concerning the distributions of the intensity and radial velocity of atomic hydrogen gas at radial velocities away from zero. The observations were made with an aerial beam of 2?2 between half-power points and a multichannel H-line receiver of channel spacing equivalent to 7 km/s and bandwidth 38 kc/s ( 8 km/s).

Motions of neutral hydrogen at high latitudes

1967 ◽  
Vol 31 ◽  
pp. 265-278 ◽  
Author(s):  
A. Blaauw ◽  
I. Fejes ◽  
C. R. Tolbert ◽  
A. N. M. Hulsbosch ◽  
E. Raimond
Keyword(s):  
Surface Density ◽  
Velocity Dispersion ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
High Latitudes ◽  
Low Velocity

Earlier investigations have shown that there is a preponderance of negative velocities in the hydrogen gas at high latitudes, and that in certain areas very little low-velocity gas occurs. In the region 100° <l< 250°, + 40° <b< + 85°, there appears to be a disturbance, with velocities between - 30 and - 80 km/sec. This ‘streaming’ involves about 3000 (r/100)2solar masses (rin pc). In the same region there is a low surface density at low velocities (|V| < 30 km/sec). About 40% of the gas in the disturbance is in the form of separate concentrations superimposed on a relatively smooth background. The number of these concentrations as a function of velocity remains constant from - 30 to - 60 km/sec but drops rapidly at higher negative velocities. The velocity dispersion in the concentrations varies little about 6·2 km/sec. Concentrations at positive velocities are much less abundant.

scholarly journals Hydrogen Content of Young Stellar Clusters. I. Methods of Observation and Reduction

1973 ◽  
Vol 26 (6) ◽  
pp. 829 ◽  
Author(s):  
HM Tovmassian
Keyword(s):  
Radio Telescope ◽  
Hydrogen Content ◽  
Data Reduction ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
Continuum Emission ◽  
Stellar Clusters ◽  
Hydrogen Line ◽  
Galactic Clusters

Observations of 16 open galactic clusters in their continuum emission and at the neutral hydrogen line have been made with the Parkes 64 m radio telescope in an attempt to determine the total amount of hydrogen gas associated with them. In this, the first of a series of five papers, the observing procedure and the method of data reduction are described.

scholarly journals Contribution to the study of the distribution of neutral hydrogen in the region 230° ≤ lII ≤ 280°

1970 ◽  
Vol 38 ◽  
pp. 157-163
Author(s):  
D. Goniadzki ◽  
A. Jech
Keyword(s):  
Radio Astronomy ◽  
Neutral Hydrogen ◽  
Hydrogen Line ◽  
Sky Survey

A sky survey of the 21 cm hydrogen line has been made with the 100-foot Radiotelescope of the I.A.R.-C.I.W. Radio Astronomy Station in the region 230° ≤ lII ≤ 280°, −15° ≤ bII ≤ −3°.We study the distribution of the local hydrogen and that in the Orion, Intermediate and Perseus arms. We find a new structure that starts at lII = 265°. We also study the concentrations which lie far below the plane; some of them seem to be related to Lindblad's G arm.

HI in the Small Magellanic Cloud Re-examined

1981 ◽  
Vol 4 (2) ◽  
pp. 189-195 ◽  
Author(s):  
R. X. McGee ◽  
Lynette M. Newton
Keyword(s):  
Radial Velocity ◽  
Neutral Hydrogen ◽  
Total Content ◽  
Hii Regions ◽  
Magellanic Cloud ◽  
Hydrogen Gas ◽  
Radial Velocities ◽  
Line Of Sight ◽  
Small Magellanic Cloud

Our re-examination of the neutral hydrogen gas in the Small Magellan Cloud has led to four important results. Firstly, we find that Hindman’s (1967) total content HI map is a satisfactory representation of the gas in the line of sight. Secondly, we find that the HI gas in the SMC exists in four distinct large masses separated from one another in radial velocity by 20 to 30 km s−1. Thirdly, having made this division of the gas we show that there is good correlation between the radial velocities of HII regions, supergiant stars and HI. Finally, we believe that our observations reveal that the SMC is associated with an extremely large trailing halo of HI gas which forms the major component of the inter-cloud bridge region.

scholarly journals 21 cm Hydrogen-line Survey of the Large Magellanic Cloud. I. Stellar, Nebular, and Neutral Hydrogen Radial Velocities

1964 ◽  
Vol 17 (4) ◽  
pp. 515 ◽  
Author(s):  
RX McGee
Keyword(s):  
Neutral Hydrogen ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Hydrogen Gas ◽  
Radial Velocities ◽  
Recent Survey ◽  
Hydrogen Line ◽  
Line Survey

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.

Southern Hemisphere Seti Survey: Five Years of Project Meta II

1997 ◽  
Vol 161 ◽  
pp. 611-621
Author(s):  
Guillermo A. Lemarchand ◽  
Fernando R. Colomb ◽  
E. Eduardo Hurrell ◽  
Juan Carlos Olalde
Keyword(s):  
Southern Hemisphere ◽  
Scattering Theory ◽  
Galactic Plane ◽  
Narrow Band ◽  
Neutral Hydrogen ◽  
Sky Survey ◽  
Inertial Frames ◽  
Interstellar Scattering ◽  
Extraterrestrial Origin ◽  
Spectral Channels

AbstractProject META II, a full sky survey for artificial narrow-band signals, has been conducted from one of the two 30-m radiotelescopes of the Instituto Argentino de Radioastronomía (IAR). The search was performed near the 1420 Mhz line of neutral hydrogen, using a 8.4 million channels Fourier spectrometer of 0.05 Hz resolution and 400 kHz instantaneous bandwidth. The observing frequency was corrected both for motions with respect to three astronomical inertial frames, and for the effect of Earths rotation, which provides a characteristic changing signature for narrow-band signals of extraterrestrial origin. Among the 2 × 1013spectral channels analyzed, 29 extra-statistical narrow-band events were found, exceeding the average threshold of 1.7 × 10−23Wm−2. The strongest signals that survive culling for terrestrial interference lie in or near the galactic plane. A description of the project META II observing scheme and results is made as well as the possible interpretation of the results using the Cordes-Lazio-Sagan model based in interstellar scattering theory.

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