Summary
 

Observation code	:	VS09p		AIPS Version	:	12DEC00
Date of Observation	:	2000/343		Difmap Version	:	2.3c
Source Name	:	J2320+0513		vsop_difmap used	:	Yes
Calibration Source(s)	:	J2148+06
Ground telescopes	:	CE, HA, MP, KL, NT, SH, TR		Model Fitted to data	:	Yes
Tracking Station(s)	:	RZ, NZ, 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 vs09p was the second Penticton correlation made on 13 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 9 March 2001. Fringes were detected during most of the run for all baselines except TR and IF2 of HA. These stations and IF without FRINGs were flagged for later imaging with difmap. Applying theses solutions without gain-tsys correction, VPLOT in AIPS with averaging all channels provided the amplitude for the tatrget spurce about 9.2*10^(-5) for CE-MP baselines, while DQA1 amplitude was 1.1*10^(-3). Assuming (DQA amplitude)*sqrt(2) provided right amplitude, I first multiplied sqrt(11/0.92) = 3.45782E+00 for each antenna in AIPS by CLCOR to adjust amplitude to that of DQA1 prior to APCAL correction. Then I multiplied sqrt(sqrt(2))= 1.1892 for the sqrt(2) correction. Tsys information obtained during the experiment was available for the GTRs except MP. Nominal information was applied for Halca and MP. The amplitude for target is about 0.7 Jy at 20 Mlambda and 0.5 Jy at 120 Jy while PLS showed 1.1 Jy at 5 Mlambda and 0.8 Jy at 120 Mlambda. For the calibrator 2.5 Jy at 110 Mlambda and 2.0 Jy at 130 Mlambda while PLS showed 3.2 Jy st 5Mlambda and 1.6 Jy at 120Mlamdga. I have a feeling that the data processed in this manner with several multiple factors is reproducing reasonable amplitude provided that variability of sources makes some difference from PLS results. The image is well modelfitted with one gaussian plus small week components.

Model
Flux (Jy)	Radius (mas)	Theta (deg)	Major (mas)	Axial ratio	Phi (deg)	TB (10^12 K)
0.446605	0.323037	152.529	0.719407	0.438599	-32.8643	0.0960
0.233356	0.232130	-9.55992	0.356532	1.00000	-63.4350	0.0896
0.00641818	0.405775	98.0935	0.0102948	1.00000	-82.8750	2.9553
(*) Quoted Brightness temperatures assume Gaussian components and are in the local (z=0) frame.

AIPS Input Files

Comments - None -

Additional Files

Name	Description
VS09P.ANTAB	Tsys information obtained during the experiment was available for the GTRs except MP. Nominal information was applied for Halca and MP.
VS09P.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_1.PS SN_APCAL_AMP_2.PS

SN_FRING1_DEL_1.PS SN_FRING1_DEL_2.PS SN_FRING1_RAT_1.PS SN_FRING1_RAT_2.PS SN_FRING1_SNR_1.PS SN_FRING1_SNR_2.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.