At NRAO, some coworkers and I undertook supervised research into a class of diffuse, low-surface brightness objects uncovered in 1997's NRAO VLA Sky Survey (NVSS), a survey to map the entire sky in at 1.4 GHz north of -40 degrees declination. The survey turned up several hundred faint objects with extended structure, most of which have not been previously observed with the VLA. Typically, these objects resemble jets and cores from active galaxies, and many correspond to elliptical galaxies. However, most display unusual configurations featuring bright knots and oddly twisting jets. The amount of dwell time during the NVSS survey on each object was minimal, and the survey revealed extremely little detail. My group had VLA time in December to take longer exposures of a few of these objects at several frequencies using polarimetry. (Though I haven't reduced the polarimetry data fro my object yet.)

• GIF contour plot of J0700+22 from the NVSS survey, winter 1996-7.

• L-band (1.4 GHz/21cm):
  L-band (1.4 GHz/21cm):
  VLA D-configuration, observed 22 Dec 1997
  Synthesized beamwidth = 44.0"
  Peak flux density of Core = 59.5 mJy
  Peak flux density of NW component = 73.2 mJy
  Peak flux density of SW component = 46.7 mJy
  Noise level: 1.1 mJy/beam
• L-band contour plot

• C-band (4.9 GHz/6cm):
  High noise level due to snow and ice in the VLA dishes and subsequent high system temperatures.
  VLA D-configuration, observed 22 Dec 1997
  Synthesized beamwidth = 14.0"
  Peak flux density of Core = 20.4mJy
  Peak flux density of NW component = 6.5 mJy
  Peak flux density of SW component = 3.0 mJy
  Noise level: 0.163 mJy/beam (approx. 3x normal)
• C-band contour plot

  Core exhibits relatively flat spectrum (in comparison to outer-lying components); only factor of three between 6cm & 21cm peak flux dens.

• X-band (8.4GHz/3.6cm):
  18 antennas in VLA D-configuration, observed 12 Feb 1998
  (Synthesized beamwidth = ~8.4")
  Peak flux density of Core = 14.4mJy
  Peak flux density of NW component = 0.29 mJy
  Peak flux density of SW component = 0.51 mJy
  Noise level: 0.12 mJy/beam
• X-band contour plot

• U-band (15 GHz/2 cm):
  18 antennas in VLA D-configuration, observed 12 Feb 1998
  Peak flux density of Core = 6.7mJy
  Noise level: 0.10 mJy/beam

• Digitized Sky Survey (DSS) Optical Image of the Elliptical Galaxy:
• DSS Optical + L-band Contour overlay
  The elliptical galaxy at ra=7h0m37.6s dec=+22d29'41.58" is the host and corresponds to the radio core.
• Polarimetry results (L-band)

Links to results/images from colleagues A. Hale, B. Ketzeback, C. Lewis, T. Perrault, R. Saxton, J.Wurnig:
• N10479+19525 images by Andy Hale (VLA D-config., L-band (1.4 GHz))

Back to main page Last modified 16 Feb 1998, 14:23 MST