scholarly journals Supernova Remnants as Radio Sources

1968 ◽  
Vol 21 (5) ◽  
pp. 739 ◽  
Author(s):  
MJL Kesteven
Keyword(s):  
Spectral Index ◽  
Radio Telescope ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Radio Sources ◽  
Evolutionary Path ◽  
Contour Maps ◽  
Galactic Sources ◽  
Cross Type

The results of a survey with the 1 mile Molonglo cross-type radio telescope of nonthermal galactic sources are discussed in terms of supernova remnant theories. The contour maps obtained indicate that most sources are consistent with a portion of a shell of emission. The results suggest that a remnant's spectral index is independent of its age. A supernova remnant evolutionary path is also derived, and compared with the path predicted by the various theories.

scholarly journals Discovery of a new supernova remnant G21.8−3.0

2020 ◽  
Vol 493 (2) ◽  
pp. 2188-2194 ◽  
Author(s):  
X Y Gao ◽  
P Reich ◽  
W Reich ◽  
L G Hou ◽  
J L Han
Keyword(s):  
Spectral Index ◽  
Radio Telescope ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Galactic Plane ◽  
Infrared Emission ◽  
Radio Continuum ◽  
Source Spectrum ◽  
Polarized Emission ◽  
Eastern Half

ABSTRACT Sensitive radio continuum surveys of the Galactic plane are ideal for discovering new supernova remnants (SNRs). From the Sino-German λ6-cm polarization survey of the Galactic plane, an extended shell-like structure has been found at ℓ = 21${^{\circ}_{.}}$8, b = −3${^{\circ}_{.}}$0, which has a size of about 1°. New observations were made with the Effelsberg 100-m radio telescope at λ11 cm to estimate the source spectrum, together with Urumqi λ6-cm and Effelsberg λ21-cm data. The spectral index of G21.8−3.0 was found to be α = −0.72 ± 0.16. Polarized emission was mostly detected in the eastern half of G21.8−3.0 at both λ6 and λ11 cm. These properties, together with the Hα filament along its northern periphery and the lack of infrared emission, indicate that the emission is non-thermal, as is usual in shell-type SNRs.

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.

Jets associated with supernova remnants and other galactic nonthermal sources

1986 ◽  
Vol 64 (4) ◽  
pp. 482-483
Author(s):  
R. H. Becker
Keyword(s):  
Black Holes ◽  
Neutron Star ◽  
Supernova Remnants ◽  
Binary Systems ◽  
Radio Sources ◽  
Nonthermal Radio ◽  
Galactic Sources ◽  
Relativistic Particles

Accreting neutron star or black holes in binary systems can, under appropriate circumstances, eject jets of particles into their environment. This is most readily observed in SS433, Sco X-1, and Cyg X-3. We infer the presence of the injection of relativistic particles in a number of other galactic sources where actual jets have not been observed. In some cases the energy imparted results in nonthermal radio sources comparable in size to supernova remnants.

scholarly journals A Catalogue of Radio Sources Between Declinations ?50° and ?80°

1961 ◽  
Vol 14 (4) ◽  
pp. 497 ◽  
Author(s):  
BY Mills ◽  
OB Slee ◽  
ER Hill
Keyword(s):  
Statistical Analysis ◽  
Radio Telescope ◽  
Small Area ◽  
Radio Sources ◽  
Low Weight ◽  
Cross Type

A catalogue has been prepared of the radio sources observed between declinations -50� and -80�, using the Sydney cross-type radio telescope at a wavelength of 3�5 m; a total of 219 sources is listed. This supplements the earlier catalogues for the declination ranges +10� to -20� and -20� to -50�. In addition to the positions and intensities of the sources, angular sizes of 42 of the strongest sources are given. As before, identifications with bright optical objects have been sought, and a number of possible identifications with emission nebulae and bright galaxies are listed. Because of the small area of sky covered by the present catalogue, the numbers of sources are small (compared with those in our earlier catalogues) so that the statistical analysis of their distribution has comparatively low weight.

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 The Radio Morphology and Possible Nature of 3C 58

1983 ◽  
Vol 101 ◽  
pp. 341-342
Author(s):  
Ma Er ◽  
Richard G. Strom
Keyword(s):  
Spectral Index ◽  
Radio Telescope ◽  
Intensity Distribution ◽  
Supernova Remnant ◽  
Published Data ◽  
Rotation Measure

Observations have been made of the supernova remnant 3C 58 with the Westerbork Synthesis Radio Telescope at 6 and 49 cm. These measurements provide us with greater resolution and sensitivity than that attained with previously published data. The 49 cm map has been used for comparison with an existing 21 cm one (Wilson and Weiler, 1976) to obtain information on the spectral index, rotation measure and depolarization. The 6 cm map is valuable both for its greater resolution, and for comparing with an observation made with the same instrument eight years previously. The total intensity distribution is shown in Figure 1.

scholarly journals Radio Maps of the Regions RCW 57 and W 49

1989 ◽  
Vol 120 ◽  
pp. 131-131
Author(s):  
N.S. Sabalisck ◽  
Z. Abrahan ◽  
C.E. Tateyama
Keyword(s):  
Spectral Index ◽  
Supernova Remnant ◽  
Angular Resolution ◽  
Radio Sources ◽  
Thermal Radio ◽  
5 Ghz

We present maps of the regions RCW57 and W59 in the frequency of 22 GHz with 4.’6 angular resolution. The thermal radio sources RCW57 II are well resolved in the map. RCW57 I presents, at this frequency a diameter twice as large as that reported at 5 GHz, obtained with similar resolution, but coincides with the size of the source at the wavelenght of 1 mm. In the map of the RCW57 region we detected also the supernova remnant G291.0-0.1, of plerionic type. We find a break in the spectrum of this source between 8 and 22 GHz, with the spectral index changing from −0.29 to −0.77. This behaviour is also found in other remnats of the same type.

scholarly journals Multifrequency observations of one of the largest supernova remnants in the local group of galaxies, LMC - SNR J0450-709

2009 ◽  
pp. 55-60 ◽  
Author(s):  
K.O. Cajko ◽  
E.J. Crawford ◽  
M.D. Filipovic
Keyword(s):  
Spectral Index ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Local Group ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
High Polarization ◽  
Typical Morphology ◽  
Peak Value ◽  
Compact Array

We present the results of new Australia Telescope Compact Array (ATCA) observations of one of the largest supernova remnants, SNR J0450-709, in the Local Group of galaxies. We found that this Large Magellanic Cloud (LMC) object exhibits a typical morphology of an old supernova remnant (SNR) with diameter D=102x75?1 pc and radio spectral index ?=-0.43?0.06. Regions of high polarization were detected with peak value of ~40%.

scholarly journals Gain Measurements of Large Aerials Used in Interferometer and Cross?Type Radio Telescopes

1958 ◽  
Vol 11 (1) ◽  
pp. 70 ◽  
Author(s):  
AG Little
Keyword(s):  
Radio Telescope ◽  
Radio Sources ◽  
Radio Telescopes ◽  
Discrete Radio Sources ◽  
Cross Type

A method has been developed for measuring the gain of large interferometer and cross-type radio telescope aerials. Use is made of the strong discrete radio sources, whose intensity need not be known, to allow comparison of the gains of the aerials with that of a standard.

Sign in / Sign up

Export Citation Format

Share Document