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Register a new userA sharper view of the outer Galaxy at 1420 and 408 MHz from the Canadian Galactic Plane Survey II: The catalogue of extended radio sources
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A new catalogue of extended radio sources has been prepared based on arcminute-resolution 1420 MHz images from the Canadian Galactic Plane Survey (CGPS). The new catalogue provides both 1420 MHz and 408 MHz flux density measurements on sources found near the Galactic plane in the second quadrant of our Galaxy. In addition cross-identifications are made with other major radio catalogues and information is provided to facilitate the recovery of CGPS image data associated with each catalogued source. Numerous new radio sources are identified and the catalogue provides a comprehensive summary of both newly discovered and previously known HII regions and supernova remnants in the outer Galaxy. The catalogue should be of use both for synoptic studies of Galactic structure and for placing higher resolution observations, at radio and other wavelengths, in context.
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Arcminute-resolution radio continuum images at 408 and 1420 MHz from the Canadian Galactic Plane Survey (CGPS) have been used to reexamine radio sources listed in the Kallas and Reich (1980) catalogue. This catalogue is of particular interest to Galactic studies as it lists both extended and compact radio sources found in the second Galactic quadrant. We have determined the nature (extended vs. compact, Galactic vs. extragalactic) of all of these bright radio sources. A number of large HII regions with no optical counterparts are highlighted along with a sample of large radio galaxies. Many sources previously thought to be extended Galactic objects are shown to be point sources. A sample of point sources with flat or rising spectra between 408 and 1420 MHz has been compiled, and within this sample likely Gigahertz Peaked Spectrum sources have been identified.
Faraday rotation provides a valuable tracer of magnetic fields in the interstellar medium; catalogs of Faraday rotation measures provide key observations for studies of the Galactic magnetic field. We present a new catalog of rotation measures derived from the Canadian Galactic Plane Survey, covering a large region of the Galactic plane spanning 52 deg < l < 192 deg, -3 deg < b < 5 deg, along with northern and southern latitude extensions around l ~ 105 deg. We have derived rotation measures for 2234 sources (4 of which are known pulsars), 75% of which have no previous measurements, over an area of approximately 1300 square degrees. These new rotation measures increase the measurement density for this region of the Galactic plane by a factor of two.
We describe the equipment, observational method and reduction procedure of an absolutely calibrated radio continuum survey of the South Celestial Hemisphere at a frequency of 1420 MHz. These observations cover the area 0h < R.A. < 24h for declinations less than -10 degree. The sensitivity is about 50 mK T_B (full beam brightness) and the angular resolution (HPBW) is 35.4, which matches the existing northern sky survey at the same frequency.
A new sample of very powerful radio galaxies is defined from the Molonglo Reference Catalogue, according to the criteria S (408 MHz) > 5 Jy, -30 < Dec < 10 degrees, |b| > 10 degrees. The sample is selected to have similar properties to the northern 3CR revised sample, and to be visible to a combination of existing northern telescopes such as the Very Large Array radio interferometer and large southern hemisphere telescope facilities. The sample contains 178 sources, of which spectroscopic redshifts are available in the literature for 128. For the remaining 50 sources, new radio imaging, optical imaging and spectroscopic observations are presented to identify the host galaxies and determine their redshifts. With these new observations the total sample is 100% optically identified and redshifts are available for 174 (98%) of the sources. The sample consists of one starburst galaxy, one Seyfert galaxy, 127 radio galaxies and 49 quasars. Basic properties of the sample, such as the distributions of the quasar and radio galaxy populations in redshift and their locations on the radio power versus linear size (P-D) diagram, show no significant differences from the revised 3CR sample. The equatorial location and the high spectroscopic completeness of this sample make it a valuable resource for detailed studies of the nature and environments of these important objects with the new generation of southern hemisphere telescopes.
We present a new 408 MHz survey (B3.1) carried out with the Croce del Nord radiotelescope in Bologna. The survey coordinates limits are $-2^circ 00^prime$ to $+2^circ 15^prime$ in Dec. and 21h to 24h, 00h to 17h in R.A., equivalent to 0.388 sr. The B3.1 is complete to 0.15 Jy but many sources down to 0.1 Jy are included. Our aim was to select a new and complete sample of Ultra Steep Spectrum (USS) radio sources, as they proved to be good candidates to find high-z radiogalaxies and their surrounding protoclusters. The observations and the reduction procedure are described and the observational errors are discussed. A cross-identification with the NVSS survey was performed to obtain the spectral index $alpha_{408}^{1400}$ and radio size of the sources. We found no evidence of a change of the spectral index distribution as radio flux decreases. The B3.1 USS sample contains 185 sources down to 0.1 Jy and it is about one order of magnitude deeper in flux with respect to the 4C USS sample. For 146 B3.1 USS sources no optical counterpart was found on the POSS-I sky survey. A cross-correlation with the FIRST survey gave maps for a subset of 50 USS sources, and their optical ID search was also made on the POSS-II, resulting in 39 empty fields
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