Summary
 

Observation code	:	VS07p		AIPS Version	:	12DEC00
Date of Observation	:	2001/45		Difmap Version	:	2.3c
Source Name	:	J0321+1221		vsop_difmap used	:	Yes
Calibration Source(s)	:	J0204+15
Ground telescopes	:	MP, KA, SH		Model Fitted to data	:	Yes
Tracking Station(s)	:	TZ		Image made	:	Yes
Correlator	:	Penticton

 

Abstract This is one of problematical experiments correlated after March 2001, same as vs01s, vs07p, vs08u, vs09p, which suffer significantly lower amplitude, about factor 10 or so, in AIPS comparing DQA1 plots provided by Penticton. We have not yet solve this problem. These data were first correlated with 32 channels/IF. I requested for vs08u to be re-correlated with 128ch/IF but no change in amplitude was observed either in AIPS or DQA1 from previous amplitudes in each system. This vs07p was the second Penticton correlation made on 11 September 2001. Note that all Penticton data generated after 28 May 2001 has *NO* need for sqrt(2) modification (Rob Shank, private communication). However the DQA plots was based on the first correlation made on 3 May 2001. Fringes were detected during most of the run for all baselines. Applying thses solutions without gain-tsys correction, VPLOT in AIPS with averaging all channels provided the amplitude 1.2*10^(-4) for KA-MP baselines, while DQA1 amplitude was 1.4*10^(-3). Assuming (DQA amplitude)*sqrt(2) provided right amplitude, I multiply sqrt(14*sqrt(2)/1.2) = 4.06192E+00 for each antenna in AIPS by CLCOR prior to ANTAB, APCAL etc. to adjust amplitude to that of DQA1. Tsys information obtained during the experiment was only available for SH. Nominal information was applied for Halca, KA and MP. The amplitude for target is about 1.0 Jy at 20 Mlambda and 0.3 Jy at 110 Jy while PLS showed 1.2 Jy at 5 Mlambda and 1.0 Jy at 120 Mlambda. For the calibrator about 1.0 Jy at both 20 Mlambda and 120 Mlambda while PLS showed 3.1Jy@5Mlambda and 2.5Jy@120Mlamdga. There still remains a feeling that the data processed in this manner is about factor 2 or so lower than expected value, but this may be due to variability of the target. The image is well modelfitted with one gaussian component.

Model
Flux (Jy)	Radius (mas)	Theta (deg)	Major (mas)	Axial ratio	Phi (deg)	TB (10^12 K)
0.679107	0.0846640	-66.4903	0.972182	0.398900	-47.5148	0.0879
(*) Quoted Brightness temperatures assume Gaussian components and are in the local (z=0) frame.

AIPS Input Files

Comments - None -

Additional Files

Name	Description
VS07P.ANTAB	Tsys information obtained during the experiment was only available for SH. Nominal information was applied for Halca, KA and MP.
VS07P.INDXR	Provided by PI-letter from Penticton

AIPS Output Files

PRTAN.LIS LISTR.LIS DTSUM_0.LIS DTSUM_1.LIS UVPLT_UV.PS UVPLT_UVD.PS UVPLT_UVPA.PS

SN_APCAL_AMP_2.PS SN_APCAL_AMP_1.PS SN_CALIB_DEL_1.PS SN_CALIB_DEL_2.PS SN_CALIB_RAT_1.PS SN_CALIB_RAT_2.PS SN_CALIB_SNR_1.PS

SN_CALIB_SNR_2.PS SN_CALIB_PHA_1.PS SN_CALIB_PHA_2.PS POSSM_AP1_01.PS POSSM_AP1_02.PS

More details on the Images and Modelfits are found in this page.