scholarly journals Some Observations of Shell-type Galactic Radio Sources

1967 ◽  
Vol 20 (3) ◽  
pp. 297 ◽  
Author(s):  
ER Hill
Keyword(s):  
Radio Emission ◽  
Spherical Symmetry ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Milky Way ◽  
Radio Sources ◽  
Radio Observations ◽  
Shell Type ◽  
Rosette Nebula ◽  
Galactic Radio

Radio evidence for two new supernova remnants in the Southern Milky Way is presented. Some new observations of the known supernova remnant, source 1439-62, and of the Rosette nebula, a shell source but not a supernova remnant, are also presented. The problem of finding model shells to fit the radio observations is considered and it is shown that the radio emission from 1439-62 is unlikely to originate in a shell with spherical symmetry.

scholarly journals Radio Emission from Novae and Supernovae

1956 ◽  
Vol 9 (1) ◽  
pp. 84 ◽  
Author(s):  
BY Mills ◽  
AG Little ◽  
KV Sheridan
Keyword(s):  
Radio Emission ◽  
Supernova Remnants ◽  
Milky Way ◽  
Radio Sources ◽  
Constant Ratio ◽  
Radio Observations ◽  
Maximum Emission ◽  
Galactic Radio Emission ◽  
Galactic Radio

Attempts have been made to observe the radio emission at 3?5 m from two supernovae and ten novae. Kepler's star was the only reasonably certain identification. A comparison with radio observations of other supernova remnants suggests a constant ratio between the present radio emission and the maximum emission of light. It is concluded that for common novae, which are not detectable as radio sources, this ratio must be smaller than for supernovae. The galactic radio emission near the plane of the Milky Way could be largely the integrated emission of supernova remnants but common novae could not contribute appreciably.

scholarly journals 8·8 GHz Radio Observations of 12 Suggested Supernova Remnants

1973 ◽  
Vol 26 (3) ◽  
pp. 379 ◽  
Author(s):  
JR Dickel ◽  
DK Milne ◽  
AR Kerr ◽  
JG Ables
Keyword(s):  
Flux Density ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Galactic Plane ◽  
Small Diameter ◽  
Radio Sources ◽  
Radio Observations ◽  
Frequency Measurements ◽  
Thermal Spectrum

Brightness distributions and flux densities at 8�8 GHz are presented for 12 small-diameter radio sources near the galactic plane. Each of these sources has been classified at one time or another as a supernova remnant. For one source, G295� 2 - 0�6, the flux density at 8�8 GHz confirms the thermal spectrum suggested by lower frequency measurements and indicates that it is not a supernova remnant. Another source, G309� 6+ 1�7, is thought to be extragalactic.

scholarly journals Radio Emission from the Supernova Remnant Vela-X

1968 ◽  
Vol 21 (2) ◽  
pp. 201 ◽  
Author(s):  
DK Milne
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Radio Emission ◽  
Spectral Index ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Magnetic Field Direction ◽  
Radio Observations ◽  
Optical Identification ◽  
Polarization Measurements

Radio observations are presented of the fairly large galactic complex Vela-X, Y, and Z. These sources are believed to be the remnant of a supernova having an optical identification with the filamentary nebula Stromlo 16. The brightness distributions, obtained at four frequencies, indicate an open annular structure reminiscent of other supernova remnants. The variation of spectral index over the region is investigated and shows that the radiation is substantially nontherm81, the integrated fluxes yielding a spectral index of -0,3. A high resolution distribution of magnetic field direction is deduced from polarization measurements made at three frequencies; a circumferential magnetic field is a possible interpretation of the field orientations.

scholarly journals Radio Emission from 16 Possible Supernova Remnants

1969 ◽  
Vol 22 (2) ◽  
pp. 211 ◽  
Author(s):  
DK Milne ◽  
ER Hill
Keyword(s):  
Radio Emission ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Radio Sources

Sixteen radio sources, thought to be supernova remnants, have been observed at several frequencies between 408 and 2700 MHz. These data, together with previously published observations, have been used to derive spectra for these sources. The validity of the supernova remnant classification of certain of these sources is questioned.

scholarly journals The Evolution of Supernova Remnants as Radio Sources

1983 ◽  
Vol 101 ◽  
pp. 187-192
Author(s):  
R. Cowsik ◽  
S. Sarkar
Keyword(s):  
Radio Emission ◽  
Interstellar Medium ◽  
Supernova Remnants ◽  
Structural Evolution ◽  
Radio Sources ◽  
Relativistic Electrons ◽  
Shell Type

The acceleration of relativistic electrons by hydromagnetic turbulence in shell-type supernova remnants (SNRs) is examined within the framework of previous studies of their structural evolution through interaction with the interstellar medium. The predicted evolution of the synchrotron radio emission by the electrons is in agreement with a wide variety of observations.

scholarly journals Some new observations relating to galactic radio sources and background structure

1964 ◽  
Vol 20 ◽  
pp. 107-114 ◽  
Author(s):  
E. R. Hill
Keyword(s):  
Radio Emission ◽  
Radio Telescope ◽  
Milky Way ◽  
Angular Resolution ◽  
Spectral Information ◽  
Radio Sources ◽  
Background Structure ◽  
The Galaxy ◽  
Galactic Radio

A survey of the distribution of radio emission at wavelengths of 75 and 20 cm along an extensive section of the Southern Milky Way has recently been carried out by M. Komesaroff and myself using the 210-foot radio telescope at Parkes. The area surveyed ranges from lII = 280 to 355° and extends on the average to 6 degrees either side of the plane. The beamwidths of the aerial at 75 and 20 cm are 50 and 14 min arc respectively. Observations at the shorter wavelength offer a picture of this section of the Galaxy at considerably higher angular resolution than hitherto available, while the 75-cm observations are expected to make a useful contribution to our spectral information.

Supernova Remnant Searches at Molonglo

1984 ◽  
Vol 5 (4) ◽  
pp. 537-540 ◽  
Author(s):  
A. J. Turtle ◽  
B. Y. Mills
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
Magellanic Clouds ◽  
Radio Observations ◽  
X Ray

A catalogue of 38 supernova remnants (SNRs) identified in the Large and Small Magellanic Clouds from X-ray, optical and radio observations has recently been presented by Mills et al. (1984). One important consideration is the completeness of this catalogue and of the Galactic catalogues with which it is compared. These are currently being investigated.

Observations of Shell-Type Galactic Radio Sources

1967 ◽  
Vol 1 (1) ◽  
pp. 21-21 ◽  
Author(s):  
E. R. Hill
Keyword(s):  
Radio Telescope ◽  
Shell Structure ◽  
Radio Spectrum ◽  
Radio Sources ◽  
Thermal Radio ◽  
Shell Type ◽  
Galactic Radio

Survey type observations have been made with the Parkes radio-telescope of 4 galactic radio sources having either a non-thermal radio spectrum, or exhibiting shell structure in their emitting regions. Observations were made at a wavelength of 11 cm using the Parkes radiotelescope where the beamwidth is about 7.5 min.arc.

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