Neutral hydrogen absorption in the quasar 3C 268.4 - Possible evidence for galactic halo clouds

1983 ◽  
Vol 269 ◽  
pp. L43 ◽  
Author(s):  
A. D. Haschick ◽  
P. C. Crane ◽  
W. A. Baan
Keyword(s):  
Hydrogen Absorption ◽  
Galactic Halo ◽  
Neutral Hydrogen

A search for neutral hydrogen absorption in the double quasar 0957 + 561

Nature ◽  
1980 ◽  
Vol 283 (5743) ◽  
pp. 175-176
Author(s):  
C. L. Bennett ◽  
C. R. Lawrence ◽  
B. F. Burke
Keyword(s):  
Hydrogen Absorption ◽  
Neutral Hydrogen

scholarly journals The Kinematics of the Magellanic Clouds

1995 ◽  
Vol 166 ◽  
pp. 273-282
Author(s):  
B.E. Westerlund
Keyword(s):  
Galactic Halo ◽  
Neutral Hydrogen ◽  
Magellanic Clouds ◽  
Great Promise ◽  
Common Envelope ◽  
The Past ◽  
Ram Pressure ◽  
Long Time ◽  
Magellanic Stream ◽  
Magellanic System

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.

scholarly journals A MERLIN neutral hydrogen absorption study of the luminous infrared merger NGC 6240

2001 ◽  
Vol 325 (1) ◽  
pp. 151-158 ◽  
Author(s):  
R. J. Beswick ◽  
A. Pedlar ◽  
C. G. Mundell ◽  
J. F. Gallimore
Keyword(s):  
Hydrogen Absorption ◽  
Neutral Hydrogen ◽  
Absorption Study

Neutral hydrogen absorption of H II regions

1978 ◽  
Vol 83 ◽  
pp. 1412 ◽  
Author(s):  
P. Silverglate ◽  
Y. Terzian
Keyword(s):  
Hydrogen Absorption ◽  
Neutral Hydrogen ◽  
H Ii Regions

Neutral hydrogen absorption within the radio galaxy 3C 178

1978 ◽  
Vol 225 ◽  
pp. 343
Author(s):  
A. D. Haschick ◽  
W. A. Baan ◽  
B. F. Burke
Keyword(s):  
Hydrogen Absorption ◽  
Radio Galaxy ◽  
Neutral Hydrogen

Neutral hydrogen absorption in the radio galaxy 3C 293

1981 ◽  
Vol 243 ◽  
pp. L143 ◽  
Author(s):  
W. A. Baan ◽  
A. D. Haschick
Keyword(s):  
Hydrogen Absorption ◽  
Radio Galaxy ◽  
Neutral Hydrogen

scholarly journals Probing Radio Intensity at High-Z from Marion: 2017 Instrument

2019 ◽  
Vol 08 (02) ◽  
pp. 1950004 ◽  
Author(s):  
L. Philip ◽  
Z. Abdurashidova ◽  
H. C. Chiang ◽  
N. Ghazi ◽  
A. Gumba ◽  
...  
Keyword(s):  
Preliminary Data ◽  
Hydrogen Absorption ◽  
Neutral Hydrogen ◽  
Absorption Feature ◽  
Marion Island ◽  
Dual Polarization ◽  
First Stars ◽  
Initial Design ◽  
Sky Brightness ◽  
Radio Intensity

We introduce Probing Radio Intensity at high-Z from Marion (PRIZM), a new experiment designed to measure the globally averaged sky brightness, including the expected redshifted 21[Formula: see text]cm neutral hydrogen absorption feature arising from the formation of the first stars. PRIZM consists of two dual-polarization antennas operating at central frequencies of 70 and 100[Formula: see text]MHz, and the experiment is located on Marion Island in the sub-Antarctic. We describe the initial design and configuration of the PRIZM instrument that was installed in 2017, and we present preliminary data that demonstrate that Marion Island offers an exceptionally clean observing environment, with essentially no visible contamination within the FM band.

scholarly journals The Magellanic Stream as a probe of the galactic halo

1979 ◽  
Vol 84 ◽  
pp. 574-574
Author(s):  
R. J. Cohen ◽  
R. D. Davies ◽  
I. F. Mirabel
Keyword(s):  
Galactic Halo ◽  
Neutral Hydrogen ◽  
The Sun ◽  
Typical Size ◽  
Stellar Component ◽  
Large Velocity ◽  
The Galaxy ◽  
Magellanic Stream

Recent observations of the Magellanic Stream can be used to set limits on a possible hot halo surrounding the Galaxy. The observations are described in detail elsewhere (Mirabel, Cohen & Davies, submitted to Mon. Not. R. astr. Soc.). Briefly, the neutral hydrogen in the northern end of the Magellanic Stream is concentrated in narrow filaments which contain small elongated clouds of typical size 0°.4 × 0°.6. These clouds have a large velocity halfpower width (25 km s−1 and are gravitationally unstable, unless there is a massive low luminosity stellar component. If we consider only the observed gas the expansion age of a typical cloud is 6 × 105 D years, where D is the distance in kpc from the Sun, and this falls at least a factor of ten short of the age of the Stream predicted by current models. This strongly suggests that some containment mechanism is operating.

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