Summary
 

Observation code	:	VS09c		AIPS Version	:	12DEC00
Date of Observation	:	2001/18		Difmap Version	:	2.3c
Source Name	:	J1430+10		vsop_difmap used	:	Yes
Calibration Source(s)	:	J1337-12
Ground telescopes	:	CE, HA, HO, MP, KL, NT, SH		Model Fitted to data	:	Yes
Tracking Station(s)	:	UZ, 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 vs09c 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 10 April 2001. Fringes were detected during most of the run for all baselines except KL and IF2 of NT. KL was flagged for later calbration. Applying thses solutions without gain-tsys correction, VPLOT in AIPS with averaging all channels provided the amplitude for calibrator J1337-12 about 7.5*10^(-4) for CE-MP baselines, while DQA1 amplitude was 1.0*10^(-2). Assuming (DQA amplitude)*sqrt(2) provided right amplitude, I multiply sqrt(10/0.75) = 3.35410E+00 for each antenna in AIPS by CLCOR to adjust amplitude to that of DQA1 prior to APCAL correction. Then I multiply 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. CD and NT were flagged by FG table generated by FITLD for some reason, but ASIP-FRING provided good solution for this antenna with FLAGVER=-1. It turned out that HO was showing remakable low amplitude, about factor 10. HO was flagged at difmap imaging. The amplitude for target is about 0.9 Jy at 20 Mlambda and 0.6 Jy at 120 Jy while PLS showed 1.3 Jy at 5 Mlambda and 1.2 Jy at 120 Mlambda. For the calibrator 5.8 Jy at 20 Mlambda and 4.0 Jy at 140 Mlambda while PLS showed 5.5Jy@5Mlambda and 5.0Jy@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)
0.835683	0.0429902	-10.4385	1.22746	0.199299	17.9882	0.1358
0.0639168	1.04787	-124.625	0.00460456	1.00000	-78.6901	147.1155
0.0177951	3.91132	-146.257	0.0709312	1.00000	-63.4350	0.1726
(*) Quoted Brightness temperatures assume Gaussian components and are in the local (z=0) frame.

AIPS Input Files

Comments - None -

Additional Files

Name	Description
VS09C.ANTAB

AIPS Output Files

PRTAN.LIS LISTR.LIS DTSUM_0.LIS DTSUM_1.LIS POSSM_AP1_01.PS POSSM_AP1_02.PS UVPLT_UV.PS

UVPLT_UVD.PS UVPLT_UVPA.PS SN_APCAL_AMP_1.PS SN_APCAL_AMP_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

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