GLOW Interferometry Tutorial: Wednesday
We will reduce the 3C129 polarization continuum dataset from the 2008 NRAO summer school. (See http://casa.nrao.edu/Tutorial/SIworkshop2008/ ) The summer school used CASA for the data reduction. You are welcome to try to use CASA for the data reduction on your own (but see also the warnings about what to do what CASA crashes frequently), but we will do the basic reduction in AIPS.
2010 Nov 16: JMA updated for 31DEC10 AIPS
Web Image of 3C129
Wide-field 90 cm image of the large head-tail radio galaxy 3C129 (right). The bright source at the left is 3C129.1. From Lane et al., AJ, 123, 2985, 2002.
The 8.5 GHz observations being reduced here will only look at the central, brightest, portion of this source.
Data Reduction
Remember, the purpose f this exercise is not to teach you how to reduce radio interferometry data with AIPS. Consider all of the arcane incantations below as just that, magic incantations. You should instead try to figure out what each step is actually doing to the data. The AIPS Cookbook has quite a bit of information to help guide you. Check out chapters 4 and 5. (Note that you probably have a copy of the cookbook in your local AIPS installation if you don't have full web access.) However, at some of the most important points, the cookbook is relatively useless for understanding what is going on, as opposed to knowing which buttons to push, so ask your tutorial leader for help in this area.
Download the data from http://casa.nrao.edu/Data/VLA/3C129/3c129data.tgz and untar it in some directory. (If you are in Garching, there should be a local copy. Ask Sven.) Then, from that same directory, start aips. Login with a new user ID number.
Basic Environment
dowait 1
dohist=1
docrt=132
dotv=1
Load the raw data: FILLM
task 'fillm'
default
nfiles 0
prtlev 0
datain 'PWD:AT166_
doconcat true
clron
doweight 10
ncount 3
cparm(4)=28
cparm(8)=10./60
dparm 0
bparm 0
timer 0
vlamode = ' '
band = ' '
calcode ' '
clron
outdisk 1
go
Check where it went. You will need the X band version at 8.5 GHz
Note that there are multiple sequence numbers for the same bands, as the observation was done using different frequency settings. We want the initial 8.5 GHz observation.
indi 1
pcat
getn 3
imhe
AIPS 1: Got(1) disk= 1 user= 100 type=UV 19940725.X BAND.2 AIPS 1: Image=MULTI (UV) Filename=19940725 .X BAND. 2 AIPS 1: Telescope=VLA Receiver=VLA AIPS 1: Observer=AT166 User #= 100 AIPS 1: Observ. date=25-JUL-1994 Map date=16-NOV-2010 AIPS 1: # visibilities 284570 Sort order TB AIPS 1: Rand axes: UU-L-SIN VV-L-SIN WW-L-SIN BASELINE TIME1 AIPS 1: SOURCE FREQSEL AIPS 1: ---------------------------------------------------------------- AIPS 1: Type Pixels Coord value at Pixel Coord incr Rotat AIPS 1: COMPLEX 3 1.0000000E+00 1.00 1.0000000E+00 0.00 AIPS 1: STOKES 4 -1.0000000E+00 1.00 -1.0000000E+00 0.00 AIPS 1: FREQ 1 8.5149000E+09 1.00 5.0000000E+07 0.00 AIPS 1: IF 2 1.0000000E+00 1.00 1.0000000E+00 0.00 AIPS 1: RA 1 00 00 00.000 1.00 3600.000 0.00 AIPS 1: DEC 1 00 00 00.000 1.00 3600.000 0.00 AIPS 1: ---------------------------------------------------------------- AIPS 1: Coordinate equinox 1950.00 AIPS 1: Maximum version number of extension files of type HI is 1 AIPS 1: Maximum version number of extension files of type AN is 1 AIPS 1: Maximum version number of extension files of type NX is 1 AIPS 1: Maximum version number of extension files of type SU is 1 AIPS 1: Maximum version number of extension files of type FQ is 1 AIPS 1: Maximum version number of extension files of type CL is 1 AIPS 1: Maximum version number of extension files of type TY is 1 AIPS 1: Maximum version number of extension files of type OF is 1 AIPS 1: Keyword = 'CORRMODE' value = ' ' AIPS 1: Keyword = 'VLAIFS ' value = 'ABCD ' AIPS 1: Keyword = 'CORRCOEF' value = -1
Print out some useful information
task 'listr'
default
getn 3
optype 'scan'
doweight 1
docrt=132
flagver 0
sources ' '
stokes ' '
docalib 0
gainuse 1
dopol -1
dparm 0
antenna 0
basel 0
stokes ' '
inext ' '
inver 0
bif 0
eif 0
uvrange 0
go
vlb054 LISTR(31DEC10) 100 16-NOV-2010 17:47:48 Page 1
File = 19940725 .X BAND. 2 Vol = 1 Userid = 100
Freq = 8.514900000 GHz Ncor = 4 No. vis = 284570
Scan summary listing
Scan Source Qual Calcode Sub Timerange FrqID START VIS END VIS
1 2345-167 : 0002 A 1 0/07:38:45 - 0/07:41:35 1 1 5236
2 A2597 : 0002 1 0/07:53:05 - 0/08:00:15 1 5237 18977
3 2345-167 : 0002 A 1 0/08:19:15 - 0/08:20:55 1 18978 22007
4 A2597 : 0002 1 0/08:32:25 - 0/08:39:35 1 22008 35677
5 2345-167 : 0002 A 1 0/08:58:25 - 0/09:00:15 1 35678 39018
6 A2597 : 0002 1 0/09:11:35 - 0/09:18:55 1 39019 53084
7 2345-167 : 0002 A 1 0/09:37:45 - 0/09:39:35 1 53085 56355
8 A2597 : 0002 1 0/09:50:55 - 0/09:58:15 1 56356 70435
9 2345-167 : 0002 A 1 0/10:17:05 - 0/10:18:55 1 70436 73790
10 A2597 : 0002 1 0/10:30:15 - 0/10:37:35 1 73791 87870
11 2345-167 : 0002 A 1 0/10:56:25 - 0/10:58:15 1 87871 91211
12 A2597 : 0002 1 0/11:09:35 - 0/11:16:55 1 91212 105291
13 2345-167 : 0002 A 1 0/11:35:45 - 0/11:37:35 1 105292 108646
14 0420+417 : 0002 B 1 0/11:46:35 - 0/11:48:15 1 108647 111676
15 3C129 : 0002 1 0/12:02:35 - 0/12:12:45 1 111677 131281
16 0420+417 : 0002 B 1 0/12:25:25 - 0/12:27:15 1 131282 134636
17 3C129 : 0002 1 0/12:39:45 - 0/12:49:55 1 134637 154172
18 0420+417 : 0002 B 1 0/13:02:35 - 0/13:04:25 1 154173 157527
19 3C129 : 0002 1 0/13:18:45 - 0/13:28:55 1 157528 175547
20 0420+417 : 0002 B 1 0/13:41:35 - 0/13:43:25 1 175548 178625
21 3C129 : 0002 1 0/13:55:55 - 0/14:06:05 1 178626 196645
22 0420+417 : 0002 B 1 0/14:18:45 - 0/14:20:35 1 196646 199665
23 3C129 : 0002 1 0/14:34:55 - 0/14:45:05 1 199666 216239
24 0420+417 : 0002 B 1 0/14:57:45 - 0/14:59:35 1 216240 219330
25 3C129 : 0002 1 0/15:10:55 - 0/15:18:15 1 219331 231264
26 0420+417 : 0002 B 1 0/15:28:05 - 0/15:29:55 1 231265 234102
27 3C129 : 0002 1 0/15:44:45 - 0/15:54:55 1 234103 250648
28 0420+417 : 0002 B 1 0/16:08:05 - 0/16:09:55 1 250649 253428
29 3C129 : 0002 1 0/16:24:35 - 0/16:34:45 1 253429 269933
30 0420+417 : 0002 B 1 0/16:47:35 - 0/16:49:25 1 269934 273011
31 0518+165 : 0002 C 1 0/17:03:05 - 0/17:06:25 1 273012 278789
32 0134+329 : 0002 C 1 0/17:18:15 - 0/17:21:35 1 278790 284570
Type Q to stop, just hit RETURN to continue
vlb054 LISTR(31DEC10) 100 16-NOV-2010 17:48:06 Page 2
File = 19940725 .X BAND. 2 Vol = 1 Userid = 100
Source summary
Velocity type = ' ' Definition = ' '
ID Source Qual Calcode RA(1950.0) Dec(1950.0) IFlux QFlux UFlux VFlux No. vis
1 2345-167 : 0002 A 23:45:27.6823 -16:47:52.600 0.000 0.000 0.000 0.000 24929
IF( 2) 0.000 0.000 0.000 0.000
2 A2597 : 0002 23:22:43.7000 -12:23:56.000 0.000 0.000 0.000 0.000 83717
IF( 2) 0.000 0.000 0.000 0.000
3 0420+417 : 0002 B 04:20:27.9370 41:43:08.045 0.000 0.000 0.000 0.000 27625
IF( 2) 0.000 0.000 0.000 0.000
4 3C129 : 0002 04:45:31.6950 44:55:19.950 0.000 0.000 0.000 0.000 136740
IF( 2) 0.000 0.000 0.000 0.000
5 0518+165 : 0002 C 05:18:16.5320 16:35:26.900 0.000 0.000 0.000 0.000 5778
IF( 2) 0.000 0.000 0.000 0.000
6 0134+329 : 0002 C 01:34:49.8320 32:54:20.520 0.000 0.000 0.000 0.000 5781
IF( 2) 0.000 0.000 0.000 0.000
ID Source Freq(GHz) Velocity(Km/s) Rest freq (GHz)
1 All Sources 8.5149 0.0000 0.0000
IF( 2) 8.8851 0.0000 0.0000
Frequency Table summary
FQID IF# Freq(GHz) BW(kHz) Ch.Sep(kHz) Sideband
1 1 8.51490000 50000.0039 50000.0039 1
2 8.88510000 50000.0039 50000.0039 1
AIPS 1: Resumes
Where are the antennas located?
go prtan
Location Of VLA Antennas
N36 (26)
N32 ( 1)
N28 (19)
N24 (11)
N20 (15)
N16 (25)
N12 (13)
N8 (27)
N4 (14)
(12) W4 E4 (22)
( 8) W8 E8 ( 4)
( 3) W12 E12 (16)
(28) W16 E16 ( 7)
( 2) W20 E20 (17)
(21) W24 E24 (24)
(10) W28 E28 ( 5)
(18) W32 E32 (23)
(20) W36 E36 ( 6)
VLA:_OUT ( 9)
VPT:_OUT (29)
Investigate the data
Plots
task 'uvplt'
source '0518+165',' '
calcode ' '
stokes 'half'
timer 0
uvrange 0
bif 0
eif 0
docalib 0
gainuse 1
bparm 0 1
aparm 0
refant 22
do3col 1
dotv 1
tvinit
go
source '0134+329',' '
tvinit
go
source '0420+417', ' '
tvinit
go
Note that the VLA Calibrator Manual says for this source:
0423+418 J2000 A 04h23m56.009795s 41d50'02.712770" Aug01 0420+417 B1950 A 04h20m27.936900s 41d43'08.039000" ----------------------------------------------------- BAND A B C D FLUX(Jy) UVMIN(kL) UVMAX(kL) ===================================================== 20cm L X X P P 2.00 visplot 3.7cm X P P P P 1.12 visplot 2cm U P P P P 0.72 visplot 0.7cm Q S S S S 1.00 visplot
So we are not exactly sure at C band (5 GHz, 6 cm) what the source structure is like for the B configuration from the manual. Is it ok to use? For what (u,v) range?
source '3C129', ' '
tvinit
go
bparm 6 7
source '0518+165',' '
tvinit
go
source '0134+329',' '
tvinit
go
source '0420+417', ' '
tvinit
go
source '3C129', ' '
tvinit
go
bparm 11,15,0
sources '0518+165','0134+329','0420+417','3C129',' '
xinc=10
go
bparm 11,16,0
go
xinc=1
bparm 0
Raw visibilities
task 'listr'
optype 'list'
antenna 22,0
basel 0
sources '0518+165','0134+329','0420+417', '3C129', ' '
calcode '*'
bif 0
eif 0
docalib 0
dparm 0
go
Source=0420+417 : 0002, Stokes=RR , IF= 1, Chans= 1- 1 Flux = 0.0000 Jy, Calcode = B , Freq = 8.514900000 GHz Amplitudes, 1000 = 1.000000 Jy, averging type = Vector Baselines 01220222032204220522062207220822102211221222132214221522162217221822192220222122222322242225222622272228 0/16:47:55 120 117 124 124 129 135 121 122 131 122 123 126 120 125 124 122 124 135 122 119 124 128 0/16:48:05 119 117 115 120 120 129 132 116 121 128 118 120 124 119 123 122 123 121 130 117 117 119 120 126 0/16:48:15 116 113 116 121 121 127 130 115 121 128 119 120 124 116 122 122 120 120 128 116 114 119 121 123 0/16:48:25 118 115 113 119 121 126 133 115 122 129 119 118 124 117 121 124 119 120 128 117 115 120 122 124 0/16:48:35 117 114 116 119 121 127 136 117 123 127 118 120 122 117 122 121 121 120 127 117 115 116 121 126 0/16:48:45 119 112 114 119 122 126 133 117 120 127 120 118 123 117 122 122 120 119 130 118 117 118 119 125 0/16:48:55 117 114 118 120 121 124 133 118 120 130 119 121 124 115 121 122 119 119 128 117 114 119 120 125 0/16:49:05 119 113 115 122 121 127 132 115 121 129 121 121 124 115 121 122 120 120 129 118 117 116 119 125 0/16:49:15 119 116 116 121 120 127 133 117 121 128 117 121 123 117 122 120 119 121 128 120 116 119 120 125 0/16:49:25 118 113 116 123 120 125 132 115 120 127 118 120 126 117 122 121 122 120 131 119 117 120 122 123 Source=0518+165 : 0002, Stokes=RR , IF= 1, Chans= 1- 1 Flux = 0.0000 Jy, Calcode = C , Freq = 8.514900000 GHz Amplitudes, 1000 = 1.000000 Jy, averging type = Vector 0/17:03:25 212 191 205 212 198 177 232 213 183 226 207 210 221 2 165 216 148 195 192 196 204 211 218 0/17:03:35 205 187 199 205 193 171 227 209 179 224 205 206 216 2 161 212 145 188 189 191 201 203 208 212 0/17:03:45 202 186 199 206 192 170 226 206 177 223 202 204 215 2 160 212 143 191 190 190 200 203 207 211 0/17:03:55 205 184 198 205 190 169 228 207 174 224 202 203 216 1 160 210 142 188 187 191 199 202 205 209 0/17:04:05 205 187 197 204 192 171 227 208 176 226 202 206 218 42 160 209 145 188 187 191 198 201 206 213 0/17:04:15 205 185 197 208 190 169 224 207 176 222 202 205 216 197 163 208 145 189 188 190 198 202 205 210 0/17:04:25 204 188 198 206 189 170 224 206 176 226 202 202 216 196 164 210 144 189 190 190 199 204 207 212 Type Q to stop, just hit RETURN to continue vlb054 LISTR(31DEC10) 100 16-NOV-2010 18:12:30 Page 3 Source=0518+165 : 0002, Stokes=RR , IF= 1, Chans= 1- 1 Baselines 01220222032204220522062207220822102211221222132214221522162217221822192220222122222322242225222622272228 0/17:04:35 204 187 197 206 190 170 227 208 175 225 203 208 217 194 161 210 144 189 190 193 198 206 205 209 0/17:04:45 206 188 198 208 191 169 227 206 176 226 203 207 214 197 161 211 145 190 188 191 198 206 207 211 0/17:04:55 207 188 199 207 190 170 227 207 177 224 204 206 216 196 161 210 144 191 188 191 199 205 205 209 0/17:05:05 205 186 200 207 192 171 226 205 175 225 201 207 219 196 160 210 142 189 189 191 197 209 206 212 0/17:05:15 206 190 198 208 189 171 227 208 175 224 204 205 217 197 161 207 141 189 190 191 197 208 205 211 0/17:05:25 203 189 199 205 189 169 228 207 174 224 202 204 216 195 160 206 144 188 190 188 199 204 208 213 0/17:05:35 203 189 200 206 193 170 226 208 176 226 202 205 215 196 162 207 145 188 187 191 198 206 206 207 0/17:05:45 202 188 199 207 192 170 225 205 175 223 202 204 216 196 160 208 143 188 188 190 197 208 206 213 0/17:05:55 202 189 200 207 190 170 228 206 175 223 203 205 219 195 158 208 143 190 190 191 201 207 208 210 0/17:06:05 203 188 197 207 191 173 231 206 174 221 203 203 217 194 162 208 141 189 188 191 200 205 205 211 0/17:06:15 204 187 200 206 190 170 227 206 177 222 206 205 217 196 162 206 145 189 189 191 197 202 207 209 0/17:06:25 204 190 200 208 192 173 226 207 175 220 204 207 216 194 162 210 144 188 189 190 199 206 205 212 Source=0134+329 : 0002, Stokes=RR , IF= 1, Chans= 1- 1 Flux = 0.0000 Jy, Calcode = C , Freq = 8.514900000 GHz Amplitudes, 1000 = 1.000000 Jy, averging type = Vector Baselines 01220222032204220522062207220822102211221222132214221522162217221822192220222122222322242225222622272228 0/17:18:35 247 246 256 263 275 264 291 261 253 281 270 266 271 2 236 267 219 251 287 265 261 271 285 0/17:18:45 242 241 253 262 272 261 287 256 250 280 263 265 268 1 234 264 215 250 282 262 259 243 269 282 0/17:18:55 246 241 252 265 273 263 289 257 252 280 265 265 267 2 238 264 217 248 283 262 257 243 266 282 0/17:19:05 241 239 249 260 268 264 287 257 249 279 263 263 271 3 234 262 216 223 282 262 258 244 266 279 0/17:19:15 240 239 248 257 264 257 288 255 248 277 263 259 269 84 234 262 214 245 280 262 255 240 264 280 0/17:19:25 245 235 247 259 266 261 284 257 247 276 259 262 268 259 236 261 214 246 278 258 256 239 263 277 0/17:19:35 244 238 249 259 269 263 283 258 248 277 263 261 269 259 236 260 215 243 279 259 254 238 262 276 0/17:19:45 240 237 251 260 266 260 284 255 248 274 262 261 269 258 234 262 215 244 279 261 255 241 264 276 0/17:19:55 245 240 250 258 267 259 287 258 247 276 259 259 267 257 236 261 217 249 281 259 255 237 265 275 0/17:20:05 240 238 249 259 266 259 286 256 247 277 262 259 267 259 235 263 216 243 283 259 256 240 264 278 0/17:20:15 242 234 251 257 264 259 284 254 247 274 260 257 272 258 233 263 215 245 278 258 253 241 261 276 0/17:20:25 245 235 253 259 270 261 286 257 252 277 262 260 271 259 234 263 216 250 280 260 256 240 266 279 0/17:20:35 240 239 253 261 269 263 289 260 249 276 264 261 272 261 235 262 220 250 280 261 258 240 268 279 0/17:20:45 245 236 253 260 266 258 286 259 248 276 262 261 270 261 232 261 217 244 283 258 255 244 264 280 0/17:20:55 245 238 254 257 267 260 284 260 248 277 265 261 272 261 237 263 217 249 282 260 254 242 265 280 0/17:21:05 242 238 251 259 267 259 281 258 245 275 262 259 268 259 232 260 219 244 280 260 256 242 267 277 0/17:21:15 242 238 254 260 268 261 288 262 247 274 262 260 269 263 233 260 217 246 285 260 257 238 267 279 0/17:21:25 246 235 251 257 268 256 286 257 246 276 260 261 268 261 228 262 216 246 281 257 253 242 265 277 0/17:21:35 247 238 254 260 271 267 287 261 249 276 264 265 269 260 237 262 218 251 282 256 256 242 266 281
dparm 1,0
go
Source=0420+417 : 0002, Stokes=RR , IF= 1, Chans= 1- 1 Flux = 0.0000 Jy, Calcode = B , Freq = 8.514900000 GHz Phase, 1000 = 1000.00000 degrees, averging type = Vector Baselines 01220222032204220522062207220822102211221222132214221522162217221822192220222122222322242225222622272228 0/16:47:55 -85 -95 90-159-108 170 91 167-133 -69 -83 142 -6-110-177 -27 62 -90 -40 -45 136 59 0/16:48:05 -82 27 -93 92-155-106 171 92 168-131 -70 -84 145 -4-106-172 -25 67 -92 -40 -46-100 131 57 0/16:48:15 -77 30 -89 96-155-104 175 95 172-128 -69 -83 146 -4-106-171 -23 72 -95 -45 -47-104 131 52 0/16:48:25 -72 34 -81 101-147 -96 172 100 176-125 -64 -80 151 3 -98-167 -19 73 -99 -46 -50-109 128 47 0/16:48:35 -74 34 -82 95-147 -97 166 98 176-126 -62 -80 146 2 -94-166 -19 71-100 -47 -45-106 126 45 0/16:48:45 -73 36 -80 96-149 -95 169 98 175-122 -61 -80 142 2 -94-162 -18 71-101 -45 -48-110 127 48 0/16:48:55 -73 34 -82 96-148 -96 175 99 176-121 -62 -82 143 3 -95-161 -17 70-101 -46 -47-108 129 49 0/16:49:05 -72 34 -85 92-146 -94 172 100 176-121 -64 -84 141 -1 -98-160 -17 67-101 -44 -47-107 129 46 0/16:49:15 -72 36 -85 92-148 -92 171 92 177-121 -60 -84 142 1 -97-159 -16 67-102 -45 -43-107 127 46 0/16:49:25 -74 34 -87 92-148 -91 169 99 174-122 -60 -85 142 1 -96-159 -13 66-102 -45 -46-106 129 46 Source=0518+165 : 0002, Stokes=RR , IF= 1, Chans= 1- 1 Flux = 0.0000 Jy, Calcode = C , Freq = 8.514900000 GHz Phase, 1000 = 1000.00000 degrees, averging type = Vector 0/17:03:25 -99 26 -80 109-155-110 174 103 -82-130 -65 -79 135 70 -93 159 -37 24 -97 -37 -49 118 42 0/17:03:35 -100 28 -80 110-151-110 173 103 -81-131 -65 -79 137 85 -91 160 -36 22 -96 -38 -49-104 119 42 0/17:03:45 -103 24 -85 104-156-112 169 100 -86-136 -70 -81 133 19 -92 159 -40 22 -93 -32 -43-101 126 47 0/17:03:55 -102 22 -88 102-157-113 169 100 -87-135 -72 -79 136 30 -90 158 -39 23 -90 -34 -44 -99 123 45 0/17:04:05 -105 23 -92 99-160-116 167 98 -88-142 -76 -82 133 23 -91 154 -40 16 -88 -31 -43 -94 129 44 0/17:04:15 -104 26 -88 101-156-114 169 103 -84-140 -73 -80 130 20 -89 156 -38 23 -89 -32 -48 -98 129 40 0/17:04:25 -105 26 -89 99-157-113 169 103 -84-141 -76 -83 131 17 -90 157 -32 23 -89 -31 -45 -96 127 42 Type Q to stop, just hit RETURN to continue vlb054 LISTR(31DEC10) 100 16-NOV-2010 18:13:14 Page 3 Source=0518+165 : 0002, Stokes=RR , IF= 1, Chans= 1- 1 Baselines 01220222032204220522062207220822102211221222132214221522162217221822192220222122222322242225222622272228 0/17:04:35 -100 32 -80 108-147-103 175 109 -76-135 -69 -77 140 25 -81 165 -22 29 -98 -42 -49-100 120 33 0/17:04:45 -101 31 -80 107-147-103 167 108 -76-142 -70 -78 142 23 -81 165 -22 28-100 -41 -45 -99 124 33 0/17:04:55 -100 33 -80 109-145-102 173 109 -76-141 -68 -80 142 23 -82 164 -21 27-101 -40 -45 -98 124 31 0/17:05:05 -102 30 -81 111-147-100 172 110 -74-141 -69 -81 141 22 -83 162 -21 28-103 -40 -45 -98 125 32 0/17:05:15 -104 34 -81 112-142 -99 170 109 -71-142 -68 -80 145 23 -85 165 -16 30-103 -41 -45-100 124 26 0/17:05:25 -105 32 -82 109-141 -96 176 109 -70-143 -68 -84 148 22 -86 168 -13 33-100 -40 -44-100 125 25 0/17:05:35 -108 32 -83 111-141 -94 174 110 -71-142 -69 -78 151 20 -90 168 -11 34 -98 -41 -45 -98 125 25 0/17:05:45 -111 33 -83 110-140 -94 172 108 -72-140 -69 -79 149 18 -94 166 -11 34 -97 -40 -44 -96 127 27 0/17:05:55 -112 35 -81 110-140 -91 174 108 -68-142 -64 -76 151 18 -93 166 -9 39 -97 -40 -45 -95 127 24 0/17:06:05 -111 34 -83 110-141 -94 174 108 -70-143 -66 -78 150 16 -95 163 -10 41 -96 -40 -43 -96 128 24 0/17:06:15 -113 32 -85 108-143 -93 171 108 -72-145 -69 -79 151 15 -97 161 -12 41 -97 -41 -42 -92 131 27 0/17:06:25 -112 32 -85 108-144 -95 171 109 -73-147 -69 -79 148 14 -98 161 -15 42 -97 -38 -42 -91 132 25 Source=0134+329 : 0002, Stokes=RR , IF= 1, Chans= 1- 1 Flux = 0.0000 Jy, Calcode = C , Freq = 8.514900000 GHz Phase, 1000 = 1000.00000 degrees, averging type = Vector Baselines 01220222032204220522062207220822102211221222132214221522162217221822192220222122222322242225222622272228 0/17:18:35 -138 62 -85 125-129 -67 172 106 28-170 -47 -92 -172 -15 -54 159 87 132-105 -17 -13 136 30 0/17:18:45 -139 55 -87 121-130 -71 169 105 25-172 -49 -94 -172-162 -57 155 86 129-100 -15 -9 -42 137 30 0/17:18:55 -139 54 -84 124-132 -70 163 104 22-174 -49 -92 -171 104 -56 149 82 127 -97 -12 -11 -45 135 28 0/17:19:05 -144 48 -86 118-130 -74 153 100 13 175 -56 -99 -177 112 -64 139 79 93 -87 -1 -3 -39 138 31 0/17:19:15 -147 46 -87 117-135 -81 152 100 7 172 -62-105 177 -19 -69 133 67 88 -80 2 6 -32 142 35 0/17:19:25 -147 42 -91 114-131 -87 149 97 -2 164 -68-108 177 -21 -76 126 62 79 -74 7 10 -28 145 39 0/17:19:35 -144 41 -86 119-130 -83 153 99 -6 165 -69-106 177 -16 -77 134 65 110 -75 2 9 -29 140 35 0/17:19:45 -147 38 -89 115-134 -88 147 93 -9 163 -79-107 170 -21 -80 129 58 101 -67 0 13 -25 142 37 0/17:19:55 -150 37 -90 115-139 -93 145 90 -15 165 -82-104 169 -21 -81 132 51 97 -64 -6 16 -24 141 39 0/17:20:05 -150 40 -83 116-143 -91 144 89 -16 167 -82 -99 168 -17 -81 136 49 94 -67 -4 16 -27 138 40 0/17:20:15 -149 41 -76 120-135 -89 148 94 -13 173 -83 -97 170 -16 -79 139 46 107 -70 -7 11 -30 132 40 0/17:20:25 -146 43 -73 123-139 -87 150 94 -13 177 -85 -96 173 -17 -77 145 46 105 -72 -4 6 -34 131 40 0/17:20:35 -147 46 -73 122-133 -91 151 94 -14 178 -85 -96 171 -21 -81 144 45 106 -68 -3 10 -36 128 44 0/17:20:45 -146 45 -71 120-137 -88 154 97 -15-178 -84 -87 172 -18 -80 150 46 93 -67 -8 11 -40 123 49 0/17:20:55 -143 49 -66 121-131 -81 160 103 -6-169 -78 -81 177 -13 -78 151 54 111 -72 -10 5 -47 117 44 0/17:21:05 -149 40 -70 114-137 -82 159 99 -9-165 -86 -83 173 -15 -82 148 53 75 -69 -7 5 -45 120 47 0/17:21:15 -153 38 -71 108-142 -82 160 98 -11-164 -92 -85 162 -16 -83 147 51 93 -70 -6 11 -40 122 50 0/17:21:25 -156 37 -74 105-144 -84 157 92 -19-170 -101 -87 154 -14 -89 140 48 99 -66 0 13 -36 124 51 0/17:21:35 -152 43 -76 104-142 -78 161 94 -13-164 -103 -84 155 -13 -85 145 52 102 -72 0 13 -39 121 47
dparm 0
Flag some bad data. Just run the commands.
task 'quack'
reason 'slow start'
sources ' '
calcode ' '
stokes ' '
timer 0
antenna 17 0
flagver 1
opcode 'beg'
basel 0
bif 1
eif 1
aparm 0
aparm(2) 72.5/60
go
reason 'quack'
sources ' '
calcode ' '
stokes ' '
timer 0
antenna 0
flagver 1
opcode 'beg'
basel 0
bif 2
eif 2
aparm 0
aparm(2) 22.5/60
go
task 'uvflg'
default
dohist 1
getn 3
antenna 14,0
basel 0
timer 0 15 10 50 0 15 55 0
stokes ' '
bif 2
eif 2
opcode 'flag'
reason 'bad ant'
outfgver 1
go
timer 0 13 25 30 0 13 27 40
go
timer 0 13 59 0 0 14 2 20
go
timer 0
bif 0
eif 0
antenna 0
Start the calibration
Set the flux values of the known calibrators
task 'setjy'
default
getn 3
source '0518+165',' '
bif 0
eif 0
optype 'calc'
aparm(2) 3
go
vlb054> SETJY1: Task SETJY (release of 31DEC10) begins vlb054> SETJY1: **WARNING: OPCODE=CALC AND FREQID = -1 vlb054> SETJY1: FREQID WILL BE RESET TO 1, CHECK YOUR RESULTS CAREFULLY vlb054> SETJY1: A source model for this calibrator is available vlb054> SETJY1: Consult the help file for CALRD for assistance vlb054> SETJY1: / Flux calculated using known spectrum vlb054> SETJY1: BIF = 1 EIF = 2 /Range of IFs vlb054> SETJY1: '0518+165 ' IF = 1 FLUX = 2.4983 (Jy calcd) vlb054> SETJY1: '0518+165 ' IF = 2 FLUX = 2.4166 (Jy calcd) vlb054> SETJY1: / Using (1995.2) VLA or Reynolds (1934-638) coefficients vlb054> SETJY1: Appears to have ended successfully vlb054> SETJY1: vlb054 31DEC10 TST: Cpu= 0.0 Real= 0
bif 1
eif 1
optype ' '
zerosp 2.4983, 0.3092, -0.0628, 0.0
go
bif 2
eif 2
zerosp 2.4166, 0.2990, -0.0607, 0.0
go
bif 0
eif 0
zerosp 0
optype 'calc'
source = '0134+329',' '
go
vlb054> SETJY1: Task SETJY (release of 31DEC10) begins vlb054> SETJY1: **WARNING: OPCODE=CALC AND FREQID = -1 vlb054> SETJY1: FREQID WILL BE RESET TO 1, CHECK YOUR RESULTS CAREFULLY vlb054> SETJY1: A source model for this calibrator is available vlb054> SETJY1: Consult the help file for CALRD for assistance vlb054> SETJY1: / Flux calculated using known spectrum vlb054> SETJY1: BIF = 1 EIF = 2 /Range of IFs vlb054> SETJY1: '0134+329 ' IF = 1 FLUX = 3.2045 (Jy calcd) vlb054> SETJY1: '0134+329 ' IF = 2 FLUX = 3.0714 (Jy calcd) vlb054> SETJY1: / Using (1995.2) VLA or Reynolds (1934-638) coefficients vlb054> SETJY1: Appears to have ended successfully vlb054> SETJY1: vlb054 31DEC10 TST: Cpu= 0.0 Real= 0
bif 1
eif 1
optype ' '
zerosp 3.2045, 0.0772, -0.1722, 0.0
go
bif 2
eif 2
zerosp 3.0714, 0.0740, -0.1650, 0.0
go
bif 0
eif 0
Get images (and thus clean components) for the calibrators
task 'calrd'
object '3c138'
band 'c'
go
object '3c48'
band 'c'
go
pcat
AIPS 1: Catalog on disk 1 AIPS 1: Cat Usid Mapname Class Seq Pt Last access Stat AIPS 1: 1 100 19940725 .C BAND. 1 UV 16-NOV-2010 13:15:34 AIPS 1: 2 100 19940725 .X BAND. 1 UV 16-NOV-2010 13:15:34 AIPS 1: 3 100 19940725 .X BAND. 2 UV 16-NOV-2010 13:15:34 AIPS 1: 4 100 19940725 .C BAND. 2 UV 16-NOV-2010 15:02:52 AIPS 1: 5 100 19940725 .U BAND. 1 UV 16-NOV-2010 13:15:34 AIPS 1: 6 100 19940725 .C BAND. 3 UV 16-NOV-2010 13:15:45 AIPS 1: 7 100 19940725 .C BAND. 4 UV 16-NOV-2010 13:15:44 AIPS 1: 8 100 19940725 .X BAND. 3 UV 16-NOV-2010 13:15:44 AIPS 1: 9 100 19940725 .X BAND. 4 UV 16-NOV-2010 13:15:45 AIPS 1: 10 100 3C138_C .MODEL . 1 MA 16-NOV-2010 15:03:51 AIPS 1: 11 100 3C48_C .MODEL . 1 MA 16-NOV-2010 15:03:55
Convert the (u,v) data to the epoch of the calibration images
Note: it is possible to change the epoch of the calibration image headers to B1950, but there would remain a small error in the rotation of the coordinate system. The proper fix is to convert the (u,v) coordinates or to rotate the images.
task 'uvfix'
clron
outdisk 1
shift 0
uvfixprm 0
go
Now fix the index table.
pcat
task 'indxr'
getn 12
cparm 0
cparm(3)= -1
bparm 0
go
cparm 0
Do the actual calibration. Start with 3C138
task 'calib'
default
getn 12
calsour '0518+165',' '
uvrange 0
antenna 0
refant 22
minamper 10
minphser 10
weightit 1
get2n 10
ncomp 0
solmode 'A&P'
aparm(6) 2
solint 2
solsub 2
cparm(3) 10
cparm(4) 10
go
clrmsg
Calibrate 3C48
calsour '0134+329',' '
get2n 11
go
clrmsg
Calibrate the phase calibrator
clr2n
calsour '0420+417', ' '
solint 0
uvrange 20 0
go
clrmsg
Check the results
task 'snplt'
antenna 0
stokes ' '
inext 'sn'
inver 1
sources ' '
timer 0
optype 'amp'
opcode 'alsi'
do3col 1
dotv 1
xinc 1
nplots 9
tvinit
go
optype 'phas'
go
inver 2
optype 'amp'
go
optype 'phas'
go
inver 3
optype 'amp'
go
optype 'phas'
go
Apply the calibration to the phase calibrator
task 'getjy'
sources '0420+417', ' '
calsour '0518+165','0134+329',' '
calcode ' '
bif 0
eif 0
antenna 0
timer 0
snver 0
go
vlb054> GETJY1: Task GETJY (release of 31DEC10) begins vlb054> GETJY1: Calibrator robust averaging used 800 of 800 gain samples vlb054> GETJY1: Source:Qual CALCODE IF Flux (Jy) vlb054> GETJY1: 0420+417 : 2 B 1 1.41467 +/- 0.00432 0.00431 vlb054> GETJY1: 2 1.40641 +/- 0.00455 0.00455 vlb054> GETJY1: Source:Qual CALCODE used total bad used tot bad vlb054> GETJY1: 0420+417 : 2 B 904 904 0 100 100 0 vlb054> GETJY1: Appears to have ended successfully vlb054> GETJY1: vlb054 31DEC10 TST: Cpu= 0.0 Real= 0 IO= 1
Redo the phase calibrator calibration
Now that the flux density of the phase calibrator has been found, redo its calibration (just to make sure there are no remnants of some subtle assumptions about its flux density left in AIPS).
inext 'sn'
inver 3
extdest
inver 0
tget calib
go
clrmsg
Apply the calibration to all sources of interest.
task 'clcal'
sources '0518+165','0134+329','0420+417', '3C129', ' '
calsour '0518+165','0134+329','0420+417', ' '
opcode 'cali'
gainver 1
gainuse 2
refant 22
interp '2pt'
doblank 1
go
Have a look at the calibration
Plots
task 'uvplt'
source '0518+165',' '
calcode ' '
stokes 'half'
timer 0
uvrange 0
bif 0
eif 0
docalib 1
gainuse 2
bparm 0 1
aparm 0
refant 22
do3col 1
dotv 1
tvinit
go
Why are the different colored points for the different subbands and polarizations not overlapping?
source '0134+329',' '
tvinit
go
Again the different colors do not overlap. Why not?
source '0420+417', ' '
tvinit
go
But here they do overlap. Why? How has this changed from before?
source '3C129', ' '
tvinit
go
Start the polarization calibration
Check the parallactic angle change
task 'listr'
sources '0518+165','0134+329','0420+417', ' '
inext 'cl'
inver 2
optype 'gain'
dparm 9,0
stokes ' '
go
Or just look at the PA plot above in the initial UVPLT section.
Make a backup of calibration values, in case we mess up
task 'tasav'
clro
outdi 1
go
Now do the polarization calibration using the phase calibrator
task 'pcal'
calsour '0420+417', ' '
timer 0
antenna 0
uvrange 20,0
bif 0
eif 0
docalib 1
gainuse 2
clr2n
pmodel 0
solint 3
soltype 'appr'
prtlev 1
refant 22
bparm 0
cparm 0
go
clrmsg
vlb054> PCAL 1: Calibration source 1 0420+417 vlb054> PCAL 1: Q+iU=( -0.02115, -0.06575) +/- ( 0.000088, 0.000088) Jy vlb054> PCAL 1: Pol. inten. = 0.06906 +/- 0.000124 Jy vlb054> PCAL 1: Pol. angle = -53.92 +/- 0.036 deg vlb054> PCAL 1: 0420+417 I,Q,U,V= 1.4147 -0.02115 -0.06575 0.00000 Jy vlb054> PCAL 1: Calibration source 1 0420+417 vlb054> PCAL 1: Q+iU=( 0.03641, 0.05888) +/- ( 0.000116, 0.000116) Jy vlb054> PCAL 1: Pol. inten. = 0.06922 +/- 0.000163 Jy vlb054> PCAL 1: Pol. angle = 29.14 +/- 0.048 deg vlb054> PCAL 1: 0420+417 I,Q,U,V= 1.4064 0.03641 0.05888 0.00000 Jy
Using the calibration, check the difference between polarizations on a polarized calibrator
task 'rldif'
source '0518+165', ' '
timer 0
antenna 0
uvrange 0
docalib 1
gainuse 2
dopol true
go
Ampscalar average of matrix = 90.43( 0.020) sigma = 0.496 Ampscalar average of matrix = -102.71( 0.065) sigma = 1.583
outputs
AIPS 1: RLDIF: Task to return/apply Right - Left phase difference AIPS 1: Adverbs Values Comments AIPS 1: ---------------------------------------------------------------- AIPS 1: CLCORPRM 90.4283 -102.7064 R-L phase difference returned AIPS 1: *rest 0
Another save, just in case
task 'tasav'
clro
outdi 1
go
What is the angle supposed to be for this calibrator?
Polarization data for C band from http://www.vla.nrao.edu/astro/calib/polar/1999/
Correct number is -22.98
Correct the measured values
for i=1 to 2;clcorp(i) = -22.98 - clcorp(i);end
Apply them
task 'clcor'
source ' '
antenna 0
timer 0
bif 0
eif 0
gainver 2
gainuse 0
opcode 'polr'
stokes 'l'
go
Check that the angles match what we expect
task 'rldif'
source '0518+165', ' '
timer 0
antenna 0
uvrange 0
docalib 1
gainuse 3
dopol true
go
Look at what AIPS gave back
outputs
AIPS 1: RLDIF: Task to return Right - Left phase difference AIPS 1: Adverbs Values Comments AIPS 1: ---------------------------------------------------------------- AIPS 1: CLCORPRM -22.98 -22.98 R-L phase difference returned AIPS 1: *rest 0
Save the tables again
task 'tasav'
clro
outdi 1
go
Now start with the smaller array data. Load it in
(Actually, in the 2010 Nov 16 version of these instructions, it is already loaded in slot 9. You can skip this step if you want.)
FILLM
task 'fillm'
default
nfiles 2
prtlev 0
datain 'PWD:AT166_
doconcat true
clron
doweight 10
ncount 1
cparm(4)=28
cparm(8)=10./60
go
Check where it went
pcat
AIPS 1: Catalog on disk 1 AIPS 1: Cat Usid Mapname Class Seq Pt Last access Stat AIPS 1: 1 100 19940725 .C BAND. 1 UV 16-NOV-2010 13:15:34 AIPS 1: 2 100 19940725 .X BAND. 1 UV 16-NOV-2010 13:15:34 AIPS 1: 3 100 19940725 .X BAND. 2 UV 16-NOV-2010 13:15:34 AIPS 1: 4 100 19940725 .C BAND. 2 UV 16-NOV-2010 15:08:27 AIPS 1: 5 100 19940725 .U BAND. 1 UV 16-NOV-2010 13:15:34 AIPS 1: 6 100 19940725 .C BAND. 3 UV 16-NOV-2010 13:15:45 AIPS 1: 7 100 19940725 .C BAND. 4 UV 16-NOV-2010 16:08:46 AIPS 1: 8 100 19940725 .X BAND. 3 UV 16-NOV-2010 13:15:44 AIPS 1: 9 100 19940725 .X BAND. 4 UV 16-NOV-2010 13:15:45 AIPS 1: 10 100 3C138_C .MODEL . 1 MA 16-NOV-2010 15:17:52 AIPS 1: 11 100 3C48_C .MODEL . 1 MA 16-NOV-2010 15:24:38 AIPS 1: 12 100 19940725 .UVFIX . 1 UV 16-NOV-2010 16:03:44 AIPS 1: 13 100 19940725 .TASAV . 1 UV 16-NOV-2010 15:49:48
Make sure we have the right one
getn 9
imhe
Get the scan information
task 'listr'
default
getn 9
optype 'scan'
doweight 1
go
vlb054 LISTR(31DEC10) 100 16-NOV-2010 21:19:54 Page 1
File = 19940725 .X BAND. 4 Vol = 1 Userid = 100
Freq = 8.514900000 GHz Ncor = 4 No. vis = 287494
Scan summary listing
Scan Source Qual Calcode Sub Timerange FrqID START VIS END VIS
1 0134+329 : 0002 C 1101/04:01:46 - 101/04:03:55 1 1 3635
2 0134+329 : 0002 C 1101/04:04:15 - 101/04:05:05 1 3636 5560
3 0056-001 : 0002 C 1101/04:11:25 - 101/04:13:45 1 5561 7731
4 0053-016 : 0002 1101/04:22:15 - 101/04:30:35 1 7732 23734
5 0053-015 : 0002 1101/04:39:04 - 101/04:47:15 1 23735 39425
6 0056-001 : 0002 C 1101/04:49:45 - 101/04:52:05 1 39426 43741
7 0053-016 : 0002 1101/05:00:35 - 101/05:08:55 1 43742 59757
8 0053-015 : 0002 1101/05:17:25 - 101/05:25:35 1 59758 74973
9 0056-001 : 0002 C 1101/05:28:05 - 101/05:30:25 1 74974 79289
10 0053-016 : 0002 1101/05:38:55 - 101/05:47:15 1 79290 95250
11 0053-015 : 0002 1101/05:55:45 - 101/06:03:45 1 95251 110616
12 0056-001 : 0002 C 1101/06:06:25 - 101/06:08:45 1 110617 114932
13 0053-016 : 0002 1101/06:17:15 - 101/06:25:36 1 114933 130948
14 0053-015 : 0002 1101/06:34:05 - 101/06:42:15 1 130949 146625
15 0056-001 : 0002 C 1101/06:44:45 - 101/06:47:05 1 146626 150928
16 0053-016 : 0002 1101/06:55:34 - 101/07:03:55 1 150929 166906
17 0053-015 : 0002 1101/07:12:25 - 101/07:20:36 1 166907 182583
18 0056-001 : 0002 C 1101/07:23:05 - 101/07:25:24 1 182584 186886
19 0420+417 : 0002 B 1101/07:31:35 - 101/07:33:26 1 186887 190226
20 0518+165 : 0002 C 1101/07:39:04 - 101/07:42:25 1 190227 196417
21 3C129 : 0002 1101/08:02:45 - 101/08:17:55 1 196418 225758
22 0420+417 : 0002 B 1101/08:25:34 - 101/08:27:25 1 225759 228387
23 0420+417 : 0002 B 1101/08:47:25 - 101/08:49:15 1 228388 231675
24 3C129 : 0002 1101/08:51:55 - 101/09:06:55 1 231676 260851
25 0420+417 : 0002 B 1101/09:15:04 - 101/09:16:55 1 260852 264196
26 3C129 : 0002 1101/09:29:56 - 101/09:40:15 1 264197 284173
27 0420+417 : 0002 B 1101/09:47:34 - 101/09:49:25 1 284174 287494
Type Q to stop, just hit RETURN to continue
vlb054 LISTR(31DEC10) 100 16-NOV-2010 21:19:56 Page 2
File = 19940725 .X BAND. 4 Vol = 1 Userid = 100
Source summary
Velocity type = ' ' Definition = ' '
ID Source Qual Calcode RA(1950.0) Dec(1950.0) IFlux QFlux UFlux VFlux No. vis
1 0134+329 : 0002 C 01:34:49.8320 32:54:20.520 0.000 0.000 0.000 0.000 5560
IF( 2) 0.000 0.000 0.000 0.000
2 0056-001 : 0002 C 00:56:31.7550 -00:09:18.750 0.000 0.000 0.000 0.000 23725
IF( 2) 0.000 0.000 0.000 0.000
3 0053-016 : 0002 00:53:28.0000 -01:36:45.000 0.000 0.000 0.000 0.000 79974
IF( 2) 0.000 0.000 0.000 0.000
4 0053-015 : 0002 00:53:52.2350 -01:31:57.790 0.000 0.000 0.000 0.000 77627
IF( 2) 0.000 0.000 0.000 0.000
5 0420+417 : 0002 B 04:20:27.9370 41:43:08.045 0.000 0.000 0.000 0.000 15923
IF( 2) 0.000 0.000 0.000 0.000
6 0518+165 : 0002 C 05:18:16.5320 16:35:26.900 0.000 0.000 0.000 0.000 6191
IF( 2) 0.000 0.000 0.000 0.000
7 3C129 : 0002 04:45:31.6950 44:55:19.950 0.000 0.000 0.000 0.000 78494
IF( 2) 0.000 0.000 0.000 0.000
ID Source Freq(GHz) Velocity(Km/s) Rest freq (GHz)
1 All Sources 8.5149 0.0000 0.0000
IF( 2) 8.8851 0.0000 0.0000
Frequency Table summary
FQID IF# Freq(GHz) BW(kHz) Ch.Sep(kHz) Sideband
1 1 8.51490000 50000.0039 50000.0039 1
2 8.88510000 50000.0039 50000.0039 1
Get antenna positions
go prtan
Location Of VLA Antennas
N18 (26)
N16 ( 1)
N14 ( 9)
N12 (11)
N10 (15)
N8 (27)
N6 (25)
N4 (14)
N2 (13)
( 3) W2 E2 ( 4)
(12) W4 E4 (22)
(21) W6 E6 (16)
( 8) W8 E8 (17)
( 2) W10 E10 (24)
(10) W12 E12 ( 5)
(18) W14 E14 (23)
(28) W16 E16 ( 7)
(20) W18 E18 ( 6)
VLA:_OUT (19)
VPT:_OUT (29)
AIPS 1: Resumes
Check out some properties of the raw data
Plots
task 'uvplt'
source '0518+165',' '
calcode ' '
stokes 'half'
timer 0
uvrange 0
bif 0
eif 0
docalib 0
gainuse 1
bparm 0 1
aparm 0
refant 3
antennas 0
do3col 1
dotv 1
tvinit
go
source '0134+329',' '
tvinit
go
source '0420+417', ' '
tvinit
go
source '3C129', ' '
tvinit
go
bparm 6 7
source '0518+165',' '
tvinit
go
source '0134+329',' '
tvinit
go
source '0420+417', ' '
tvinit
go
source '3C129', ' '
tvinit
go
bparm 0
Raw numbers
task 'listr'
optype 'list'
antenna 4,0
basel 0
sources '0518+165','0134+329','0420+417', '3C129', ' '
calcode '*'
bif 0
eif 0
docalib 0
stokes ' '
dparm 0
go
dparm 1 0
go
dparm 0
Flag some bad data. Just run the commands and think about this later.
task 'quack'
reason 'quack'
sources ' '
calcode ' '
stokes ' '
timer 0
antenna 0
flagver 1
opcode 'beg'
basel 0
bif 0
eif 0
aparm 0
aparm(2) 22.5/60
go
task 'uvflg'
default
dohist 1
getn 9
antenna 0
basel 0
timer 101 4 3 50 101 4 4 20
stokes ' '
bif 0
eif 0
opcode 'flag'
reason 'dropout'
outfgver 1
go
timer 0
bif 0
eif 0
antenna 0
Begin the calibration
Apply the flux densities for the known calibrators
task 'setjy'
default
getn 9
source '0518+165',' '
bif 0
eif 0
optype 'calc'
aparm(2) 3
go
vlb054> SETJY1: Task SETJY (release of 31DEC10) begins vlb054> SETJY1: **WARNING: OPCODE=CALC AND FREQID = -1 vlb054> SETJY1: FREQID WILL BE RESET TO 1, CHECK YOUR RESULTS CAREFULLY vlb054> SETJY1: A source model for this calibrator is available vlb054> SETJY1: Consult the help file for CALRD for assistance vlb054> SETJY1: / Flux calculated using known spectrum vlb054> SETJY1: BIF = 1 EIF = 2 /Range of IFs vlb054> SETJY1: '0518+165 ' IF = 1 FLUX = 2.4983 (Jy calcd) vlb054> SETJY1: '0518+165 ' IF = 2 FLUX = 2.4166 (Jy calcd) vlb054> SETJY1: / Using (1995.2) VLA or Reynolds (1934-638) coefficients vlb054> SETJY1: Appears to have ended successfully vlb054> SETJY1: vlb054 31DEC10 TST: Cpu= 0.0 Real= 0
bif 1
eif 1
optype ' '
zerosp 2.4983, 0.3092, -0.0628, 0.0
go
bif 2
eif 2
zerosp 2.4166, 0.2990, -0.0607, 0.0
go
bif 0
eif 0
zerosp 0
optype 'calc'
source = '0134+329',' '
go
vlb054> SETJY1: Task SETJY (release of 31DEC10) begins vlb054> SETJY1: **WARNING: OPCODE=CALC AND FREQID = -1 vlb054> SETJY1: FREQID WILL BE RESET TO 1, CHECK YOUR RESULTS CAREFULLY vlb054> SETJY1: A source model for this calibrator is available vlb054> SETJY1: Consult the help file for CALRD for assistance vlb054> SETJY1: / Flux calculated using known spectrum vlb054> SETJY1: BIF = 1 EIF = 2 /Range of IFs vlb054> SETJY1: '0134+329 ' IF = 1 FLUX = 3.2045 (Jy calcd) vlb054> SETJY1: '0134+329 ' IF = 2 FLUX = 3.0714 (Jy calcd) vlb054> SETJY1: / Using (1995.2) VLA or Reynolds (1934-638) coefficients vlb054> SETJY1: Appears to have ended successfully vlb054> SETJY1: vlb054 31DEC10 TST: Cpu= 0.0 Real= 0
bif 1
eif 1
optype ' '
zerosp 3.2045, 0.0772, -0.1722, 0.0
go
bif 2
eif 2
zerosp 3.0714, 0.0740, -0.1650, 0.0
go
bif 0
eif 0
Convert the (u,v) data to the epoch of the calibration images
Note: it is possible to change the epoch of the calibration image headers to B1950, but there would remain a small error in the rotation of the coordinate system. The proper fix is to convert the (u,v) coordinates or to rotate the images.
task 'uvfix'
clron
outdisk 1
shift 0
uvfixprm 0
go
Now fix the index table.
pcat
task 'indxr'
getn 16
cparm 0
cparm(3)= -1
bparm 0
go
cparm 0
Run the calibration for 3C138
task 'calib'
default
getn 16
calsour '0518+165',' '
uvrange 0
antenna 0
refant 3
minamper 10
minphser 10
weightit 1
get2n 10
ncomp 0
solmode 'A&P'
aparm(6) 2
solint 1
solsub 2
cparm(3) 10
cparm(4) 10
go
clrmsg
Calibrate 3C48
get2n 11
calsour '0134+329',' '
solint 1
uvrange 0
go
clrmsg
Calibrate the phase calibrator
In this step we will try to get an amplitude calibration of the phase calibrator. Only the first scan seems to be good in amplitude, so set the time range for just it.
clr2n
calsour '0420+417', ' '
solint 40./60
uvrange 0
timer 101 0 0 0 101 8 0 0
go
clrmsg
Check the results
task 'snplt'
antenna 0
stokes ' '
inext 'sn'
inver 1
sources ' '
timer 0
optype 'amp'
opcode 'alsi'
do3col 1
dotv 1
nplots 9
tvinit
go
optype 'phas'
go
inver 2
optype 'amp'
go
optype 'phas'
go
inver 3
optype 'amp'
go
optype 'phas'
go
Use the amplitude calibrator to get the phase calibrator flux density
task 'getjy'
sources '0420+417', ' '
calsour '0518+165','0134+329',' '
calcode ' '
bif 0
eif 0
antenna 0
timer 0
snver 0
go
vlb054> GETJY1: Task GETJY (release of 31DEC10) begins vlb054> GETJY1: Calibrator robust averaging used 818 of 818 gain samples vlb054> GETJY1: Source:Qual CALCODE IF Flux (Jy) vlb054> GETJY1: 0420+417 : 2 B 1 1.50919 +/- 0.00369 0.00369 vlb054> GETJY1: 2 1.50224 +/- 0.00401 0.00401 vlb054> GETJY1: Source:Qual CALCODE used total bad used tot bad vlb054> GETJY1: 0420+417 : 2 B 416 416 0 104 104 0 vlb054> GETJY1: Appears to have ended successfully vlb054> GETJY1: vlb054 31DEC10 TST: Cpu= 0.0 Real= 0
Redo the phase calibrator calibration
Now that we know the flux density of the phase calibrator, run through its calibration again, just to be sure AIPS doesn't have some information left around from calibrating before with an unknown flux density. This time, run through the entire time range.
inext 'sn'
inver 3
extdest
inver 0
tget calib
timer 0
go
clrmsg
Apply the calibration to all sources
task 'clcal'
sources '0518+165','0420+417', '0134+329','3C129', ' '
calsour '0518+165','0420+417', '0134+329',' '
opcode 'cali'
gainver 1
gainuse 2
refant 3
interp '2pt'
doblank 1
go
Check the results
Plots
task 'uvplt'
docalib 1
gainuse 2
source '0420+417', ' '
stokes 'half'
aparm 0
bparm 0 1
doweight 1
uvrange 0
tvinit
go
Now start the polarization calibration
Check the paralactic angles
task 'listr'
sources '0518+165','0420+417', ' '
inext 'cl'
inver 2
optype 'gain'
dparm 9,0
go
Make a backup of calibration information
task 'tasav'
clro
outdi 1
go
Run the polarization calibration on the phase calibrator
task 'pcal'
calsour '0420+417', ' '
timer 0
antenna 0
uvrange 20,0
bif 0
eif 0
docalib 1
gainuse 2
clr2n
pmodel 0
solint 3
soltype 'appr'
prtlev 1
refant 3
bparm 0
cparm 0
go
clrmsg
vlb054> PCAL 1: Calibration source 1 0420+417 vlb054> PCAL 1: Q+iU=( -0.01935, 0.08692) +/- ( 0.000536, 0.000536) Jy vlb054> PCAL 1: Pol. inten. = 0.08905 +/- 0.000758 Jy vlb054> PCAL 1: Pol. angle = 51.28 +/- 0.172 deg vlb054> PCAL 1: 0420+417 I,Q,U,V= 1.5092 -0.01935 0.08692 0.00000 Jy vlb054> PCAL 1: Calibration source 1 0420+417 vlb054> PCAL 1: Q+iU=( 0.08929, -0.01579) +/- ( 0.000699, 0.000699) Jy vlb054> PCAL 1: Pol. inten. = 0.09068 +/- 0.000988 Jy vlb054> PCAL 1: Pol. angle = -5.02 +/- 0.221 deg vlb054> PCAL 1: 0420+417 I,Q,U,V= 1.5022 0.08929 -0.01579 0.00000 Jy
Check the phase difference between polarizations on a polarization calibrator
task 'rldif'
source '0518+165', ' '
timer 0
antenna 0
uvrange 0
docalib 1
gainuse 2
dopol true
go
outputs
AIPS 1: RLDIF: Task to return Right - Left phase difference AIPS 1: Adverbs Values Comments AIPS 1: ---------------------------------------------------------------- AIPS 1: CLCORPRM -55.2632 -171.0893 R-L phase difference returned AIPS 1: *rest 0
Make backups again
task 'tasav'
clro
outdi 1
go
Find out what the polarization angle on the sky is supposed to be
Polarization data for C band from http://www.vla.nrao.edu/astro/calib/polar/1999/
Correct number is -22.98
Correct the measured values
for i=1 to 2;clcorp(i) = -22.98 - clcorp(i);end
Apply the corrections
task 'clcor'
source ' '
antenna 0
timer 0
bif 0
eif 0
gainver 2
gainuse 0
opcode 'polr'
stokes 'l'
go
Check that the angles are now correct
task 'rldif'
source '0518+165', ' '
timer 0
antenna 0
uvrange 0
docalib 1
gainuse 3
dopol true
go
outputs
AIPS 1: RLDIF: Task to return Right - Left phase difference AIPS 1: Adverbs Values Comments AIPS 1: ---------------------------------------------------------------- AIPS 1: CLCORPRM -21.71 -21.71 R-L phase difference returned AIPS 1: *rest 0
##########################
Work on just the target data now
Run SPLIT on the two datasets
task 'split'
getn 12
source '0518+165','0134+329','0420+417','3C129', ' '
timer 0
bif 0
eif 0
docalib 1
gainuse 3
dopol true
stokes ' '
douvcomp false
aparm 0
go
getn 16
go
clrmsg
Check for where the new datafiles are stored
pcat
AIPS 1: Catalog on disk 1 AIPS 1: Cat Usid Mapname Class Seq Pt Last access Stat AIPS 1: 1 101 19940725 .C BAND. 1 UV 13-NOV-2008 17:24:12 AIPS 1: 2 101 19940725 .X BAND. 1 UV 13-NOV-2008 17:24:13 AIPS 1: 3 101 19940725 .X BAND. 2 UV 13-NOV-2008 17:24:13 AIPS 1: 4 101 19940725 .C BAND. 2 UV 13-NOV-2008 18:24:07 AIPS 1: 5 101 19940725 .U BAND. 1 UV 13-NOV-2008 17:24:13 AIPS 1: 6 101 3C138_C .MODEL . 1 MA 13-NOV-2008 17:51:33 AIPS 1: 7 101 3C48_C .MODEL . 1 MA 13-NOV-2008 16:19:09 AIPS 1: 8 101 19940725 .TASAV . 1 UV 13-NOV-2008 17:24:13 AIPS 1: 9 101 19940725 .TASAV . 2 UV 13-NOV-2008 17:24:13 AIPS 1: 10 101 19941103 .C BAND. 1 UV 13-NOV-2008 17:24:36 AIPS 1: 11 101 19941103 .X BAND. 1 UV 13-NOV-2008 17:24:36 AIPS 1: 12 101 19941103 .X BAND. 2 UV 13-NOV-2008 17:24:36 AIPS 1: 13 101 19941103 .C BAND. 2 UV 13-NOV-2008 18:24:18 AIPS 1: 14 101 19941103 .TASAV . 1 UV 13-NOV-2008 17:54:20 AIPS 1: 15 101 19941103 .TASAV . 2 UV 13-NOV-2008 17:56:30 AIPS 1: 16 101 3C129 .SPLIT . 1 UV 13-NOV-2008 18:24:07 AIPS 1: 17 101 3C129 .SPLIT . 2 UV 13-NOV-2008 18:24:18
Combine the two different observations into one big one
task 'dbcon'
getn 20
get2n 26
go
pcat
AIPS 1: 27 100 3C129 .DBCON . 1 UV 16-NOV-2010 22:13:56
Imaging
IMAGR is the standard imaging tool for AIPS
This will start up an imaging/cleaning session. Draw boxes and clean the source structure. Do this for all 4 Stokes parameters. (Unfortunately, IMAGR requires separate runs for the different Stokes parameters.)
task 'imagr'
default
getn 27
stokes 'i'
dopol 0
cellsize 0.15,0.15
imsize 2048,2048
clr2n
do3dimag 1
docalib 0
uvrange 0
niter 20000
overlap 1
dotv 1
go
clrmsg
stokes 'q'
go
clrmsg
stokes 'u'
go
clrmsg
stokes 'v'
go
clrmsg
Check where the files went
pcat
AIPS 1: 29 101 3C129 .IBM001. 3 MA 13-NOV-2008 19:46:00 AIPS 1: 30 101 3C129 .ICL001. 5 MA 13-NOV-2008 19:46:00 AIPS 1: 31 101 3C129 .QBM001. 1 MA 13-NOV-2008 19:47:30 AIPS 1: 32 101 3C129 .QCL001. 1 MA 13-NOV-2008 19:47:30 AIPS 1: 33 101 3C129 .UBM001. 1 MA 13-NOV-2008 19:49:06 AIPS 1: 34 101 3C129 .UCL001. 1 MA 13-NOV-2008 19:49:06 AIPS 1: 35 101 3C129 .VBM001. 1 MA 13-NOV-2008 19:49:39 AIPS 1: 36 101 3C129 .VCL001. 1 MA 13-NOV-2008 19:49:39
Polarization images
Combine Q and U to get linear polarization
task 'comb'
opcode 'polc'
getn 32
get2n 34
aparm 0
bparm(1) 28E-6
bparm(2) 28E-6
go
Get the linear polarization angle
opcode 'pola'
go
Check where file went
pcat
AIPS 1: 28 101 3C129 .PPOLC . 1 MA 13-NOV-2008 19:59:45 AIPS 1: 37 101 3C129 .PANG . 1 MA 13-NOV-2008 20:00:28
Look at the images
Linear Polarization
getn 28
tvinit
tvlod
tvfiddle
tvstat
AIPS 1: Mean= 1.3417E-05 rms= 2.8180E-05 JY/BEAM over 178694. pixels
Polarization Angle
getn 37
tvinit
tvlod
tvfiddle
I
getn 30
tvinit
tvlod
tvfiddle
tvstat
Clip the data so we only see information where there is good S/N
task 'comb'
getn 37
get2n 28
opcode 'clip'
aparm(1) 100E-6
aparm(10) 100E-6
bparm 0
outclass 'PANGC'
go
task 'comb'
getn 28
get2n 28
opcode 'clip'
aparm(1) 100E-6
aparm(10) 100E-6
bparm 0
outclass 'POLCC'
go
Check where these files went
pcat
AIPS 1: 38 101 3C129 .PANGC . 1 MA 13-NOV-2008 20:31:21 AIPS 1: 39 101 3C129 .POLCC . 1 MA 13-NOV-2008 20:31:21
Look at the polarization angle
getn 38
tvinit
tvlod
tvfiddle
Plotting your data
Plot I contours and P greyscale
task 'kntr'
getn 30
get2n 28
docont 1
dogrey 2
dovect 0
pixrange 0 1E-3
clev 28E-6
levs=-16,-8,8,16,32,64,128,256,512,1024
dowedge true
cbplot 1
dotv 1
blc 950 950
trc 1500 1500
go
Plot I contours and colors for polarization angle
task 'pcntr'
getn 30
get2n 32
get3n 34
docont 1
dogrey 2
dovect 1
pixrange 0 1E-3
clev 28E-6
levs=-16,-8,8,16,32,64,128,256,512,1024
factor 5
pol3col 1
pcut 80E-6
icut 0
dowedge 0
cbplot 1
dotv 1
blc 950 950
trc 1500 1500
go
Final Images
