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1982A&A...108...227Wink
Results of a radio survey for new compact HII regions
Wink J.W., Altenhoff W.J., Mezger P.G.
Summary
This paper containes an investigation of 91 sources which appear to be
point sources when observed with the angular resolution of the 100-m telescope
at 4.9 GHz, teta_a = 2.6', and which we expected to be HII regions.
The basic search list was prepared from the 4.9 GHz survey of the galactic
plane by Altenhoff et al. (1978). These sources (or subsamples of these
sources, respectively) were observed in the continuum at 5, 15, and 86 GHz
with single dish telescope, and at 2.7 and 8.1 GHz with a three-element
interferometer. Another subsample was searched for its H90alpha and H76alpha
recombination line emission. For varios reasons a number of previosly known
compact HII regions was included in some of the single-dish and interferometer
observations.
Five out the 91 sources of the basic list were found to be non-thermal
sources and another was indentified with a known planetary nebula.
...
I.Single dish continuum observations
To determime the spectral index of a source we made cross scans through
its peak in galactic coordinates, using the 100-m telescope at 4.9 and
14.8 GHz, where the telescope HPBW is 2.6' and 1.0' respectively.
The observing mode was beam switching in the primary focus with beams
alighed in galactic latitude.
GHz HPBW' Telescope Fluxes NGC7027
4.875 2.6 100m 5.50
8.875 1.5 100m 6.15
14.8 1.0 100m 6.05
86 1.3 11m 5.02
Column 1-4 give gal. and equatorial(1950) coordinates derived from
14.8 GHz observations. The positional accuracy is typically: ~5".
Columns 5-8 give the peak flux densities at 4.9, 8.9, 14.8 and 86 GHz,
respectively. The 4.9 GHz observations were already incorporated in
Altenhoff et al.(1978). In the present paper we list 4.9 GHz flux densities
only for sources for sources for which we present new observations.
The errors are typically less than 5 % or 0.05 Jy at 4.9, 8.9, 14.8 GHz
and about 15 % or 0.2 Jy at 86 GHz.
Column 9 gives the deconvolved half power width of the source (HPW)
obtained from 14.8 GHz observations. Column 10 and 11 give,
for extended sources, the intergrated flux densities at 4.9 and 14.8 GHz,
respectively, assuming gaussian source and beam shape.
These were calculated using the ralation integral{B_v D_Omega} =
S_peak(1+ (teta_s/teta_A)^2), with S_peak and teta_s from table 2 and
teta_A from Table 1, respectively.
For those cases where the HPW's derived at 4.9 and 14.8 GHz are not
too different Column 12 gives the spectral index alpha (S~v^+alpha)
derived from the integrated flux densities.
Symbols in the last column have the following meaning:
* source structure indicated
a source size obtained from 4.875 GHz data
Symbols in the last column have the following meaning:
* source structure indicated
a source size obtained from 4.875 GHz data
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name RA 1950 DEC 1950 S_peak (Jy) at GHz TETA S_tot at GHz Sp.
l b hh mm ss dd mm ss 4.875 8.875 14.8 86 '15GHz 4.875 14.8 index Remarks
-------------------------------------------------------------------------------------------------
359.277 -0.264 17 41 43.6 -29 40 14 1.41 0.88 0.52 1.5 1.89 1.69 -0.1
359.281 -0.826 17 43 56.5 -29 57 44 1.28 0.77 0.39 1.75 1.8 1.58 -0.1