The Effelsberg 6 cm Survey of the Galactic plane

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Дата изменения: Wed Mar 18 12:25:10 2015
Дата индексирования: Sun Apr 10 02:00:10 2016
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Поисковые слова: п п п п п п п п п п р п р п р п р п р п р п р п р п р п р п

The Effelsberg 6 cm Survey of the Galactic plane [ CATS home ] [ Back to CATS list ] [ ftp ]

1978A&AS...36...23Altenhoff

Survey of the Galactic plane at 4.785 GHz

W.J. Altenhoff, D. Downes, T.Pauls and J. Schraml

Abstract

A survey of the galactic plane has been made with the Effelsberg 100-m telescope at a frequency of 4.875 GHz with a beamwidth of 2.6'. The data are presented as radio contour maps covering l=357.5 to 60^o, b=+-1^o, together a list of 1186 radio sources. The primary calibration source was NGC7027, which was assumed to have a flux density of 5.9 Jy. The uncertainty in the day-to-day thermal calibration was +-5 to 10%. For a point source, 1 Jy = 1.3+-0.03 K antenna temperature = 2.00 +- 0.05 K main-beam brightness temperature. For contours which extend over several degrees of sky, we estimate that 1 K Ta = 1.1K Tb.

Table 1 is a list of 1186 sources from the survey. Some sources in relatively unconfused fields were reobserved with short scans in l and b , and fitted with gaussians.

The sources parameters in table 1 were derived as follows:
* in Remarks column: positions, half-power widths and intensities from gaussian fits;
** in Remarks column: complex source; position from contour map; positions, half-power width and intensity from gaussian fits;
all other sources: parameters from contour maps.

1,2 Source coordinates in galactic longitude and latitude, accurate to +-0.005^o.
3,4 Source coordinates RA and DEC 1950.
5 Peak flux (Jy) of the source after the background has been subtracted. The units are in Jy for equivalent point sources. For the flux derived from gaussian fits, the uncertainty is ~5 %.
6 Asterisks denote gaussian fits. Designation are given only for well-known sources with widely-used names, particularly from molecular-line studies. In a complex of sources, we give the name only for the strongest peak. With increasingly higher resolution, most of the older source designations have become obsolete, and we suggest that the sources should be mainly referred to by l/b.
7 Approximate source diameter, as observed with 2.6' beam. The value is the geometric mean of the half-power widths in l-b. For sources with a peak intensity of 0.1 Jy, the letter P stands for point source, and "EXT" means that the source is extended, and the exact size is uncertain to ~10%. The diameters of the remaining sources were estimated to the nearest 0.5' from the contour map, and should be regarded with caution.
8 Integrated fluxes were estimated (****only in CATS!****) as
Flux = Peak flux * (diam/2.6')^2.

Diameters measured from contour maps are notoriously unreliable and we expect that synthesis observations with beamwidths of a few arcsec would resolve many of the sources into compact components. We therefore did not de-convolve the apparent diameters, or estimate integrated fluxes for the sources.

Example:
Glll.lll+b.bbb - Bonn (Effelsberg) at 4875 MHz
  l       b      RA1950     DEC1950   P_flux diam'Rem   T_flux
G357.658-0.079 17 37 00.9 -30 56 37    5.18  4.0  **     12.26