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Australia Telescope Compact Array
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12mm observing sessions - 1999 and 2000
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About twelve observing runs have been done at 22 GHz (observing with centre frequencies
of at 22.256 and 22.384 or 23.104 and 23.232) to attempt to detect these
sources. Five runs consisted of a single baseline, four runs consisted of
three baselines; the other runs produced minimal on no data.
The interim receivers have linearly polarized feeds, whereas the Mopra
receiver has circularly polarized feeds. The Parkes receiver had poor
elliptical polarization because of problems in accomodating it within
the ATCA receiver room.
An attempt has been made to account for atmospheric extinction.
20 & 22 June 1999
Two antennas (CA02 - CA03) were used with the Parkes and Mopra
receivers. Baseline length was 61 meters (file cals1.uv & cals2.uv).
Primary calibrator was Jupiter (this was consistent with Mars; measured
flux of 0134+329 was also consistent with near-simultaneous VLA measurements -
See
Steve Meyer's work).
24 November 1999
Three antennas (CA03 and CA04 with the interim receivers
and CA05 with the Mopra receiver) were used.
Baseline lengths were 31, 245 and 276 m for baselines 3-4, 4-5
and 3-5 respectively (file cals3.uv). Primary calibrator was Jupiter.
8 February 2000
Three antennas (CA03 and CA04 with the interim receivers
and CA05 with the Mopra receiver) were used.
Baseline lengths were 1087, 337 and 1423 m for baselines 3-4, 4-5
and 3-5 respectively (file cals4.uv).
A planet was not available for primary calibration for this run.
Primary calibrator was 1334-127 with flux of 11.6 Jy. This value is
from a near-simultaneous VLA measurement. See
Steve Meyer's work. This gives a flux for 0826-373 which is consistent
with other measurements (0826-373 appears fairly stable). However,
it gives a 12% lower value for 1741-038
than near-simultaneous VLA measurement - but this source is quite
variable, and it is quite plausible that the discrepancy is the result of
variability.
13 & 14 June 2000
Suspect data.
Receivers as for 8 February. Baseline lengths were 536, 214 and 750 m for
baselines 3-4, 4-5 and 3-5 respectively. Antenna 3 was bad for most of
14 June. Flux calibration on 14th also shows poorer consistency with other
days (files: cals5.uv, cals5a.uv, cals5bx.uv & cals5cx.uv).
15, 16 & 17 July 2000
Two antennas (CA03 and CA04) with the interim receivers were
used on a baseline of
30m (files cals6.uv, cals7.uv & cals8.uv). The observations on
17th were a quick, speculative look at some sources with possible
DASI associations. Primary calibrator was Jupiter.
27 September 2000
Suspect data.
Two antennas with the interim receivers were used on a baseline of
1086m (files cals9.uv), and returned a minimal amount of data.
14 December 2000
Two antennas with the new 12mm receivers were used on a baseline of
60m (files cals10.uv). There were problems with the second frequency, so these
were discarded. The fluxes seem to be a factor of two greater than other
similar observations. The noide diode was not in a calibrated state.
Primary calibrator was Jupiter.
15 December 2000
This consisted of observations of the PMN sources in the DASI field, done
by Edward Boyce.
31 December 2000
Although three antennas were available, CA05 was very noisy, and discarded.
Observing frequency was 23104 and 23232 MHz. There appeared to be some
interference! This observation was part of C905 (Gruppioni, Prandoni, Sault).
The baseline length was 153m. Phase stability was quite poor for some of
the observation, and so vector averages can show considerable decorrelation.
Primary calibrator was Jupiter. This was consistent with Mars (flux of
0420-014 is 13% lower than near-simultaneous VLA measurements;
however 0420-014 is quite variable. See
Steve Meyer's work).
Original: Bob Sault