First Galactic Plane survey at 8.35 and 14.35 GHz
                                       
                                  [INLINE]
                                      
                                  [INLINE]
                                      
Galactic center region at 8.35 GHz (top) and 14.35 GHz (bottom)

      Glen Langston, Anthoney Minter, Larry D'Addario, Keri Eberhardt,
                     Katrina Koski, and Julianne Zuber
                                      
   We present the first images of the galactic plane ( |b| < 5 degree, l
   = -15 degree to 255 degree) at 8.35 and 14.35 GHz. These observations
   used the NRAO/NASA Green Bank Earth Station to survey the sky
   simultaneously at these frequencies. These are the first results from
   the Galactic Plane (GP) survey observations, a program to monitor the
   sky at 8.35 and 14.35 GHz. The GP survey series is intended to detect
   short lived radio sources. We present four independent observations of
   the galactic plane, combined to provide a set of reference images of
   the galactic plane. We compare the relative brightness of Cassiopeia A
   and Cygnus A and find the rate of decrease of Cassiopeia A is slower
   than previously reported. The first survey, GPA, covers 0.82 sr (6.5
   \%) of the sky. A source list is presented for all sources brighter
   than 0.9 Jy at 8.35 GHz and also for all sources brighter than 2.5 Jy
   at 14.35 GHz. The FITS format images, residual images, source lists
   and archive data are available (8,500,000 Bytes each).
     * Cygnus Region; 8.35 GHz 
     * Cygnus Region; 14.35 GHz .
     * -15 to 75 longitude; 8.35 GHz 
     * -15 to 75 longitude; 14.35 GHz 
     * 75 to 165 longitude; 8.35 GHz 
     * 75 to 165 longitude; 14.35 GHz 
     * 165 to 255 longitude; 8.35 GHz 
     * 165 to 255 longitude; 14.35 GHz 
       
                                Submitted Paper
                                       
   A postscript version of a description of the GPA survey is available.
   The LaTeX is also available. The 10 figures from the paper are
   presented below. A large (26,000,000 byte) color postscript version of
   the figures is also available
   
                                  [LINK] 
                                      
Optics geometry for Green Bank Earth Station. The main antenna surface, M1, is
left, the sub-reflector, M2, is below the prime focus. The frequency selective
surface (FSS), M3, is above the 8.35 GHz horn. and the ellipsoidal mirror, M4,
is above the 14.35 GHz horn. Both the 8.35 and 14.35 GHz horns view the same
region of the sky simultaneously.

                                  [LINK] 
                                      
Schematic diagram showing the organization of data sampling for the 4 Sessions
comprising the GPA survey. Samples are taken 9 times a second, every 2.4\arcm.
Sections are labeled by the center galactic longitude (degrees).

                               [LINK] [LINK] 
                                      
Cygnus Loop Region of galactic plane, showing calibration sources Cygnus A
(north west), DR21 and NGC7027 (south east). The 8.35 GHz image is left and
14.35 image right. The flux density range shown is -1.5 (dark blue) to 5 (red)
Jy. Sources brighter than 5 Jy are shown in white and noise features more
negative than -1.5 Jy are shown in black. The de-convolved source size is shown
with ovals, scaled by a factor of two for clarity. Upper limits on the source
size are shown as circles. Due to source confusion along the galactic plane,
source labels are located at $b = 4\degee$ for sources with $b > 0$ and labels
are located at $b = -4\degree for sources with $b < 0$. FITS format images are
available for further study at 8.35 GHz and 14.35 GHz . (Zoom in on the color
8.35 GHz and 14.35 GHz images.)

                                  [INLINE]
                                      
                                  [INLINE]
                                      
Figure 4: Image of Galactic Plane at 8.35 and 14.35 GHz. The figure shows
Galactic Longitude from 345\degree to 30\degree and $ | b | < 5\degree$. The
flux density scale is -.5 to 5 Jy. Sources with flux density greater than 5 Jy
are shown in red, while regions of little emission are shown in blue. The 8.35
GHz image is above of the 14.35 GHz image.

                                  [INLINE]
                                      
                                  [INLINE]
                                      
Figure 5: Image of Galactic Plane at 8.35 and 14.35 GHz. The figure shows
Galactic Longitude from 30\degree to 75\degree and $ | b | < 5\degree$.

                                  [INLINE]
                                      
                                  [INLINE]
                                      
Figure 6: Image of Galactic Plane at 8.35 and 14.35 GHz. The figure shows
Galactic Longitude from 75\degree to 120\degree and $ | b | < 5\degree$.

                                  [INLINE]
                                      
                                  [INLINE]
                                      
Figure 7: Image of Galactic Plane at 8.35 and 14.35 GHz. The figure shows
Galactic Longitude from 120\degree to 165\degree and $ | b | < 5\degree$.

                                  [INLINE]
                                      
                                  [INLINE]
                                      
Figure 8: {Image of Galactic Plane at 8.35 and 14.35 GHz. The figure shows
Galactic Longitude from 165\degree to 210\degree and $ | b | < 5\degree$.

                                  [INLINE]
                                      
                                  [INLINE]
                                      
Figure 9: Image of Galactic Plane at 8.35 and 14.35 GHz. The figure shows
Galactic Longitude from 210\degree to 255\degree and $ | b | < 5\degree$.

                                  [LINK] 
                                      
Figure 10: Spectral index distribution ($S(nu) = k nu^{alpha}) of GPA sources
for sources detected at both 8.35 and 14.35 GHz.

Source Lists

   A TeX format ASCII source list is available for both 8.35 and 14.35
   GHz The columns of these tables are separated by the & symbol. The
   columns are 1) source name, 2) Right Ascension (J2000), 3) Declination
   (J2000), 4) peak flux density at 8.35 GHz (Jy) 5) Total flux density
   (Jy), 6) de-convolved source FWHM size of major axis or limiting size
   (arc min) 7) if present, size of minor axis of source (arc min), 8)
   source position angle (degrees). 9) Right Ascension (J2000), 10)
   Declination (J2000), 11) peak flux density at 14.35 GHz (Jy) 12) Total
   flux density (Jy), 13) de-convolved source FWHM size of major axis or
   limiting size (arc min) 14) if present, size of minor axis of source
   (arc min), 15) source position angle (degrees). 16) Spectral index/ID
   
                                  [LINK] 
                                      
Multi-wavelength Milky Way site at GSFC provides a good overview

NRAO

   The National Radio Astronomy Observatory (NRAO) is a facillity of the
   National Science Foundation operated under cooperative agreement with
   the Associated Universities, Inc.
   
  Green Bank
  
   The tracking station is located in the beautiful mountains of West
   Virginia. The Orbiting VLBI tracking station, Green Bank, West
   Virginia is one of four NASA tracking stations dedicated to support of
   the space VLBI missions in Japan and Russia.
   
   
    glangsto@nrao.edu
    
   Last update: 99 May 4