scholarly journals 6 cm Observations of Nonthermal Radio Sources Near the Galactic Plane

1969 ◽  
Vol 22 (5) ◽  
pp. 613 ◽  
Author(s):  
DK Milne
Keyword(s):  
Supernova Remnants ◽  
Galactic Plane ◽  
Brightness Distribution ◽  
Radio Sources ◽  
Nonthermal Radio

Brightness distributions and flux densities at 5000 MHz are presented for 17 nonthermal sources (possible supernova remnants) together with their spectra derived from these and other observations. For most sources a comparison has been made between the brightness distribution at 5000 MHz and that obtained with comparable resolution at 408 MHz with the Molonglo 1 mile Cross.

scholarly journals Extended Polarized Emission Structures in the Galactic Plane at 11 cm Wavelength

1990 ◽  
Vol 140 ◽  
pp. 63-64
Author(s):  
N. Junkes ◽  
E. Fürst ◽  
W. Reich
Keyword(s):  
Supernova Remnants ◽  
Spiral Structure ◽  
Galactic Plane ◽  
Radio Sources ◽  
Galactic Magnetic Field ◽  
Background Component ◽  
Polarized Emission ◽  
The Galaxy ◽  
Galactic Longitude ◽  
Thermal Background

Data from the Effelsberg Galactic plane survey at 11 cm wavelength have been used to produce a survey of polarized intensity in the first Galactic quadrant. Besides polarized sources (Supernova remnants and extragalactic objects) extended polarized emission features are visible, which are not connected to distinct radio sources. To decide whether these features reflect characteristics of the local field or the distant spiral structure of the Galaxy we performed an integration of polarized intensities as a function of Galactic longitude. An anticorrelation with the thermal background component suggests a distance of more than 6 kpc for some components of the polarized emission. This enables us to derive an upper limit for the uniform component of the Galactic magnetic field.

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 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 Survey of OH Masers at 1665 and 1667 MHz. I. Galactic Longitudes 326° to 40°

1980 ◽  
Vol 33 (3) ◽  
pp. 639 ◽  
Author(s):  
JL Caswell ◽  
RF Haynes ◽  
WM Goss
Keyword(s):  
Supernova Remnants ◽  
Luminosity Function ◽  
Galactic Plane ◽  
Line Emission ◽  
Zeeman Splitting ◽  
State Transitions ◽  
Line Profiles ◽  
Polarization Data ◽  
Hii Region ◽  
Nonthermal Radio

The galactic plane between longitudes 3260 and 3400 has been searched for OH emiSSIOn and bsorption on the 1665 and 1667 MHz transitions. Forty main-line emission sources were detected (27 new ones, 13 previously known), and these constitute a sample complete to a weIl-defined lower intensity limit in this region of sky. Line profiles of all sources are shown and the statistics on variability and on the intensity ratios of the ground state transitions are summarized. The completeness of the sample encouraged us to make a first attempt to construct a luminosity function and to estimate the total number of such masers in our Galaxy. A study of the velocity structures showed these to be extremely varied, but none exceed a total range of 25 km s -1; combined velocity and polarization data are compatible with a Zeeman splitting origin for the circular polarization, and with this interpretation several sources yield an estimate for the line-of-sight magnetic field strength of a few mG. Preliminary investigations of the associations with other celestial objects indicate that many of the masers are loosely associated with HII region complexes, but in at least eight instances no HII regions have yet been detected; of these eight masers, two may be associated with supernova remnants and one with an unidentified nonthermal radio source.

VLA observations of compact radio sources in the galactic plane - A search for Crab-like supernova remnants

1984 ◽  
Vol 89 ◽  
pp. 819 ◽  
Author(s):  
D. J. Helfand ◽  
D. Chance ◽  
R. H. Becker ◽  
R. L. White
Keyword(s):  
Supernova Remnants ◽  
Galactic Plane ◽  
Radio Sources

scholarly journals The Ratan Galactic Plane Survey

1998 ◽  
Vol 179 ◽  
pp. 103-105
Author(s):  
S.A. Trushkin
Keyword(s):  
Spectral Data ◽  
Supernova Remnants ◽  
Milky Way ◽  
Galactic Plane ◽  
Radio Continuum ◽  
Radio Sources ◽  
Optical Identification ◽  
Source Distance ◽  
The Galaxy

Now in radio continuum surveys more than 10,000 radio sources have discovered in the Milky Way plane but the Galactic origin only of a small part of them has been determined. The problem comes from the absence of estimates of source distance and the optical identification even for bright radio sources, and the most of sources have not spectral data at 2-3 frequencies. As followed some hundreds of sources have not classified as thermal or non-thermal. Now we don't know the full number of supernova remnants (SNRs) in the Galaxy. The simple estimates show that a sample of Galactic SNRs is not full as for weak and extended (> 15′) as for bright and compact (< 3′) SNRs (Trushkin 1993).

The Galactic Plane Radio Source G321.48 + 1.02: is it Extragalactic?

1992 ◽  
Vol 10 (1) ◽  
pp. 21-23
Author(s):  
J. L. Caswell ◽  
R. T. Stewart
Keyword(s):  
Radio Source ◽  
Supernova Remnants ◽  
Galactic Plane ◽  
Radio Sources ◽  
Galactic Latitude ◽  
Thermal Radio

Abstractstrong non-thermal radio sources at low galactic latitude may be young galactic supernova remnants or else distant extragalactic objects located in the direction of the galactic plane merely by chance. Here, we have imaged G321.48 + 1.02 with the Australia Telescope in order to distinguish between these alternatives for this source.

scholarly journals Study of the Galactic radio sources in the SCORPIO survey resolved by ATCA at 2.1 GHz

2019 ◽  
Author(s):  
A Ingallinera ◽  
G Umana ◽  
C Trigilio ◽  
R Norris ◽  
T M O Franzen ◽  
...  
Keyword(s):  
Supernova Remnants ◽  
Galactic Plane ◽  
Radio Sources ◽  
H Ii Regions ◽  
Extended Radio ◽  
Galactic Source ◽  
Extended Sources ◽  
Early Operations ◽  
First Time ◽  
Source Extraction

Abstract We present a catalogue of a large sample of extended radio sources in the SCORPIO field, observed and resolved by the Australia Telescope Compact Array. SCORPIO, a pathfinder project for addressing the early operations of the Australia SKA Pathfinder, is a survey of ∼5 square degrees between 1.4 and 3.1 GHz, centered at l = 343.5○, b = 0.75○ and with an angular resolution of about 10 arcsec. It is aimed at understanding the scientific and technical challenges to be faced by future Galactic surveys. With a mean sensitivity around $100\ \mu \mathrm{Jy\ beam}^{-1}$ and the possibility to recover angular scales at least up to 4 arcmin, we extracted 99 extended sources, 35 of them detected for the first time. Among the 64 known sources 55 had at least a tentative classification in literature. Studying the radio morphology and comparing the radio emission with infrared we propose as candidates 6 new H ii regions, 2 new planetary nebulae, 2 new luminous blue variable or Wolf–Rayet stars and 3 new supernova remnants. This study provides an overview of the potentiality of future radio surveys in terms of Galactic source extraction and characterization and a discussion on the difficulty to reduce and analyze interferometric data on the Galactic plane.

scholarly journals A Sino-German λ6 cm polarisation survey of the Galactic plane

2019 ◽  
Vol 623 ◽  
pp. A105 ◽  
Author(s):  
X. Y. Gao ◽  
P. Reich ◽  
L. G. Hou ◽  
W. Reich ◽  
J. L. Han
Keyword(s):  
Survey Data ◽  
Supernova Remnants ◽  
Large Scale ◽  
Angular Resolution ◽  
Galactic Plane ◽  
Thermal Emission ◽  
Small Diameter ◽  
Radio Continuum ◽  
High Angular Resolution ◽  
Radio Sources

Context. Large-scale radio continuum surveys provide data to get insights into the physical properties of radio sources. H II regions are prominent radio sources produced by thermal emission of ionised gas around young massive stars. Aims. We identify and analyse H II regions in the Sino-German λ6 cm polarisation survey of the Galactic plane. Methods. Objects with flat radio continuum spectra together with infrared and/or Hα emission were identified as H II regions. For H II regions with small apparent sizes, we cross-matched the λ6 cm small-diameter source catalogue with the radio H II region catalogue compiled by Paladini and the infrared H II region catalogue based on the WISE data. Effelsberg λ21 cm and λ11 cm continuum survey data were used to determine source spectra. High angular resolution data from the Canadian Galactic Plane Survey and the NRAO VLA Sky Survey were used to solve the confusion when low angular resolution observations were not sufficient. Extended H II regions were identified by eye by overlaying the Paladini and the WISE H II regions onto the λ6 cm survey images for coincidences. The TT-plot method was employed for spectral index verification. Results. A total of 401 H II regions were identified and their flux densities were determined with the Sino-German λ6 cm survey data. In the surveyed area, 76 pairs of sources are found to be duplicated in the Paladini H II region catalogue, mainly due to the non-distinction of previous observations with different angular resolutions and 78 objects in their catalogue are misclassified as H II regions, being actually planetary nebulae, supernova remnants, or extragalactic sources that have steep spectra. More than 30 H II regions and H II region candidates from our λ6 cm survey data, especially extended ones, do not have counterparts in the WISE H II region catalogue, of which 9 are identified for the first time. Our results imply that some more Galactic H II regions still await to be discovered and the combination of multi-domain observations is important for H II region identification. Based on the newly derived radio continuum spectra and the evidence of infrared emission, the previously identified SNRs G11.1−1.0, G20.4+0.1 and G16.4−0.5 are believed to be H II regions.

scholarly journals The MOST Galactic Plane Survey

1997 ◽  
Vol 14 (1) ◽  
pp. 73-76 ◽  
Author(s):  
A. J. Green
Keyword(s):  
Supernova Remnants ◽  
Galactic Plane ◽  
Field Of View ◽  
Radio Sources ◽  
The Galaxy

AbstractThe Molonglo Observatory Synthesis Telescope (MOST) has been upgraded to increase the diameter of the field of view from 70′ to 2·7°. A survey of the Galactic Plane is proposed to completely cover the region 240° ≤ l ≤ 365°, ∣ b ∣ ≤ 10° with a (1σ) sensitivity of 1–2 mJy. The results will provide a major resource for the investigation of supernova remnants, HII regions and transient radio sources. They will also be correlated with the galaxy search from the HI multibeam survey to be conducted at the Parkes telescope.

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