VS11j Results
Submitted checklist.txt and checklist.tex is also available		   [Summary | AIPS | Difmap ]
Analyst: Sandor Frey
Date Prepared: 25-10-2001
 

Summary
 
Observation code : VS11j    AIPS Version : 31DEC01   
Date of Observation : 1999/89    Difmap Version : 2.4b 
Source Name : J1940-6907    vsop_difmap used : No 
Calibration Source(s) :          
Ground telescopes : Hobart, Mopra, Hartebeesthoek  Model Fitted to data : Yes 
Tracking Station(s) : NZ, TZ    Image made : No 
Correlator : Penticton         

 
Abstract
GOT experiment code v047w. The source 1935-692 (z=3.15) was not detected on space baselines and appears very weak on ground baselines as well. The initial amplitude calibration of the ground antennas seems internally consistent. *If* the calibration is believable, the correlated flux density on the shortest HO-MP baseline is ~40 mJy, on the longer HH-HO and HH-MP baselines is just ~10 mJy. Thus no need to re-observe with HALCA.
Model
Flux (Jy)
Radius (mas)
Theta (deg)
Major (mas)
Axial ratio
Phi (deg)
TB (10^12 K)
0.0348298 0.00216791 -66.1368 0.939538 1.00000 0.00000 0.0019
(*) Quoted Brightness temperatures assume Gaussian components and are in the local (z=0) frame.


AIPS Data Reduction Notes
 
Task
Adverbs
CL
in
SN
in
CL
out
SN
out
Comments
FITLD doconcat = 1
clint = 0.5
 
 
 
 
 file read in 4 pieces 
MSORT sort = 'tb'
 
 
 
 
  
TABED inext = 'an'
inver = 1
outver = 1
optyp = 'repl'
aparm = 5, 0, 0, 6, 0
bcount = 3
ecount = 3
keyvalue = 0
 
 
 
 
 fix incorrect antenna type (MNTSTA: altaz->0) in column 5, row 3 of AN table for Hobart 
TABED same as above, except:
bcount = 4
ecount = 4
keyvalue = 2,0
 
 
 
 
 fix incorrect antenna type (MNTSTA: orbi->2) in column 5, row 4 of AN table for VSOP_SC 
FIXWT bif = 1
bchan = 100
xinc = 10
detime = -1
 
 
 
 
  
INDXR cparm = 0, 0, 0.5, 0
 
 
1 
 
 no PI letter 
ANTAB
 
 
 
 
 Gain curve information from VSOP calibration web page. Nominal Tsys used for Mopra and HALCA, measured Tsys for HartRAO and Hobart. 
APCAL
 
 
 
1 
  
CLCAL opcode = 'cali'
interpol = '2pt'
refant = 1
1 
1 
2 
 
 Amplitude calibration solutions applied; refant=HartRAO 
FRING timer 0 23 0 0 1 1 0 0
docalib = 1
flagver = -1
refant = 1
search = 3, 2, 0
solint = 5
aparm = 2, 0, 0, 0, 2, 1,
   3, 0, 1, 0
dparm = 3, 600, 300, 0
2 
 
 
2 
 trial search for fringes; no space fringes found, just like at the correlator 
FRING timer 0
docalib = 1
antenn = 1, 4, 0
flagver = -1
refant = 1
search = 0
solint = 15
aparm = 2, 0, 0, 0, 0, 1,
   0.01, 0
dparm = 1, 0, 0, 0, 1, 0
2 
 
 
3 
 an attempt to detect weak fringes between HartRAO and HALCA (low SNR, long solint); failed 
FRING timer 0
antenn = -4, 0
docalib = 1
flagver = -1
refant = 1
search = 3, 0
solint = 10
aparm = 2, 0, 0, 0, 0, 1,
   3, 0, 1, 0
dparm = 3, 600, 300, 0
2 
 
 
4 
 proceed without VSOP_SC, just ground data only 
CLCAL opcode = 'cali'
interpol = 'ambg'
2 
4 
3 
 
 final fringe-fit solutions applied 
TACOP
3 
 
4 
 
 CL table copied before gain correction 
CLCOR opcode = 'gain'
antenn = 0
clcorprm = 1.1892, 0
4 
 
4 
 
 correlator gain correction for Penticton: sqrt(sqrt(2))=1.1892 at each antenna 
SPLIT aparm = 3, 0.8357, 0, 1, 0
4 
 
 
 
 create single-source file, IFs averaged 
FITTP
 
 
 
 
 data written out for "analysis" in Difmap 

AIPS Input Files
ANTAB.TXT
INDXR.TXT		 Comments
No measured Tsys for MP and HALCA, nominal values are used.

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_FRING01_DEL_1.PS
SN_FRING01_DEL_2.PS		 SN_FRING01_RAT_1.PS
SN_FRING01_RAT_2.PS
SN_FRING01_SNR_1.PS
SN_FRING01_SNR_2.PS
SN_FRING02_DEL_1.PS
SN_FRING02_DEL_2.PS
SN_FRING02_RAT_1.PS
SN_FRING02_RAT_2.PS
SN_FRING02_SNR_1.PS
SN_FRING02_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
POSSM01_AP_1.PS
POSSM01_AP_2.PS
IMAGE.FITS


Difmap Data Reduction Notes
Phase selfcal applied? No
Global amplitude selfcal (gscal) applied? No
Amplitude selfcal on non-global timescales used? No
Modelfit made and saved? Yes
Image Made and saved? No
Comments on Difmap processing
data averaged into 30 s bins; a priori amplitude calibration (3 ground antennas) is consistent; source seems very weak, although phases are rather well aligned around 0 (this may raise the question whether amplitude calibration is correct; but cannot be checked by any means - calibrator data missing, source apparently has not been imaged with VLBI before); no selfcal and imaging attempted; circular Gaussian model (S=35 mJy, fwhm=0.94 mas) fits the visibility data well

Modelfit
Ampl, Phase vs (u,v) Distance
PS (26 kb)
JPEG (35 kb)
 Ampl, Phase vs Time
PS (116 kb)
JPEG 1, 2		 (u,v) Coverage
PS (14 kb)
JPEG (27 kb)
Closure Phase vs Time
PS (66 kb)
JPEG 1		 Image with model components
PS (33 kb)
JPEG (39 kb)

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

Model
Flux (Jy)
Radius (mas)
Theta (deg)
Major (mas)
Axial ratio
Phi (deg)
TB (10^12 K)
0.0348298 0.00216791 -66.1368 0.939538 1.00000 0.00000 0.0019
(*) Quoted Brightness temperatures assume Gaussian components and are in the local (z=0) frame.


Last updated on Fri Oct 26 18:25:25 GMT 2001
by db_results.pl version 0.3.