scholarly journals A 21 cm Survey of the Southern Milky Way

1959 ◽  
Vol 12 (3) ◽  
pp. 270 ◽  
Author(s):  
PJ Kerr ◽  
JV Hindman ◽  
CS Gum
Keyword(s):  
Milky Way ◽  
Hydrogen Line ◽  
Line Radiation

A study has been made of 21 cm hydrogen-line radiation around the Southern Milky Way, using a beamwidth of 1�.4 and a bandwidth of 40 kc/s (8�5 km/sec).

scholarly journals Hydrogen-line observations on the coma cluster

1959 ◽  
Vol 9 ◽  
pp. 465-465
Author(s):  
C. A. Muller
Keyword(s):  
Coma Cluster ◽  
Hydrogen Line ◽  
Line Radiation ◽  
Antenna Temperature ◽  
Cluster Of Galaxies

In 1956 and 1958 Heeschen [1, 2] reported hydrogen-line radiation at 21 cm from the Coma cluster of galaxies. He found a maximum antenna temperature of 2 °K and gave a profile with a width of about 4 Mc/s. From his details, it seems clear that these results depend mainly on a large number of drift curves on a frequency of 1386.9 Mc/s, since the accuracy of other points of the profile was much lower. Because the intensity is low and near the limit of what can be observed with present-day receivers we decided to repeat some of the observations with the 21-cm equipment at Dwingeloo.

Observations of binary X-ray sources with Ariel 5

1976 ◽  
Vol 350 (1663) ◽  
pp. 441-461
Keyword(s):  
Stellar Wind ◽  
Proportional Counter ◽  
Milky Way ◽  
Light Curves ◽  
Systematic Variation ◽  
Survey Experiment ◽  
Line Radiation ◽  
X Ray ◽  
Secondary Star ◽  
Sky Survey

Ariel 5 observations of the established X-ray binary sources are presented. Most of the new results are from the Leicester Sky Survey Experiment which made extended observations of the Milky Way in November 1974 and again in July-August 1975. The light curves of Cen X-3 and Vel X-l are found to have attenuation features which are attributed to shocks near the secondary star and provide evidence in support of stellar wind-driven accretion in these sources. An extended observation of Cyg X-1 is described in which there is evidence of the 5.6-day period of the associated optical binary. A systematic variation of spectral hardness (temperature) with the intensity of the Cyg X-3 source is found and further spectral observations by the M. S. S. L. proportional counter spectrometer reveal the presence of a strong monochromatic feature near 6.5 keV, probably attributable to line radiation from highly ionized iron.

scholarly journals 2. 21-cm. observations in Sydney

1957 ◽  
Vol 4 ◽  
pp. 14-18 ◽  
Author(s):  
Martha Stahr Carpenter
Keyword(s):  
Milky Way ◽  
Spiral Structure ◽  
Galactic Plane ◽  
Hydrogen Line ◽  
Line Work

The primary project in the current 21-cm. hydrogen-line work in Sydney is a study of the southern Milky Way by F. J. Kerr, J. V. Hindman, and the author. Earlier observations* made at the Radiophysics Laboratory during 1954 yielded a tentative picture of spiral structure in the southern portion of the conventional galactic plane. That picture, slightly modified by more recent results, is shown in Fig. 1.

scholarly journals Energetic flares on RS CVn stars

1989 ◽  
Vol 104 (2) ◽  
pp. 115-118
Author(s):  
J.G. Doyle ◽  
P.B. Byrne ◽  
G.H.J. van den Oord
Keyword(s):  
Transition Region ◽  
Temperature Interval ◽  
Magnetic Energy ◽  
Flare Activity ◽  
Hydrogen Line ◽  
Line Radiation ◽  
Rs Cvn Stars ◽  
Show Evidence ◽  
Radiative Losses ◽  
Flare Model

AbstractUltraviolet spectroscopic observations of the RS CVn star II Peg in February 1983 show evidence for flare activity in greatly enhanced chromospheric and transition region emission lines. The total radiative losses from the chromosphere and transition region (i.e. the temperature interval 4.0 ≤ log Te ≤ 5.4) during the flare is 3.1 1035 erg. Over the whole atmosphere (i.e. the temperature interval 4.0 ≤ log Te ≤ 8.0), we estimate total radiative losses of 2.4 1036 erg, (excluding hydrogen line radiation). At flare peak, the flare radiated 1.5 1032 erg s–1. Adopting a two-ribbon flare model, where the filament is located between the two stars of the system, we can have 2039(l/R⊙) erg of magnetic energy available, where l is the filament length and we have taken a magnetic field strength of 1000G. Therefore, only a small fraction of this magnetic energy need be converted into heating of the flare plasma.

Variation of the amount of hydrogen along the galactic ridge

1967 ◽  
Vol 31 ◽  
pp. 171-172
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Surface Brightness ◽  
Milky Way ◽  
Neutral Hydrogen ◽  
Line Of Sight ◽  
Optical Surface ◽  
Hydrogen Density ◽  
Continuous Radiation ◽  
Galactic Longitude

The integralNHof neutral-hydrogen density along the line of sight is determined from the Kootwijk and Sydney surveys. The run ofNHwith galactic longitude agrees well with that of thermal continuous radiation and that of the optical surface brightness of the Milky Way.

Astronomers spot first fast radio burst in the Milky Way

Nature ◽  
2020 ◽  
Vol 582 (7812) ◽  
pp. 322-323 ◽  
Author(s):  
Alexandra Witze
Keyword(s):  
Radio Burst ◽  
Milky Way ◽  
Fast Radio Burst
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