ATNF VLBI Wiki

v255w

Description	Proper motion and Parallax of Methanol Masers: A search for infalling ga
Antennas	At-Cd-Ho-Mp-Hh-Wa
Start	324 23:00:00
Stop	325 23:00:00
PI	S.P. Ellingsen

Setup v255w.5cm:

Station Modes	At Cd Ho Mp
Channel 1	`IFP#1-LO 6642 - 6658 MHz USB RCP`
Channel 2	`IFP#1-HI 6658 - 6674 MHz USB RCP`
Channel 3	`IFP#2-LO 6642 - 6658 MHz USB LCP`
Channel 4	`IFP#2-HI 6658 - 6674 MHz USB LCP`
DAS 1 Skyfreq	6658 MHz
Bandwidth	16 MHz
DAS Mode	vsop.pro (telescope)

Station Modes	Hh Wa
Channel 1	`6642 - 6658 MHz USB RCP`
Channel 2	`6642 - 6658 MHz USB LCP`
Channel 3	`6658 - 6674 MHz USB RCP`
Channel 4	`6658 - 6674 MHz USB LCP`
Bandwidth	16 MHz
DAS Mode	Mark5

Setup v255w.5cm-icrf:

Station Modes	At Cd Ho Mp
Channel 1	`IFP#1-LO 6300 - 6316 MHz USB RCP`
Channel 2	`IFP#1-HI 6316 - 6332 MHz USB RCP`
Channel 3	`IFP#2-LO 6642 - 6658 MHz USB LCP`
Channel 4	`IFP#2-HI 6658 - 6674 MHz USB LCP`
DAS 1 Skyfreq	6316 & 6658 MHz
Bandwidth	16 MHz
DAS Mode	vsop.pro (telescope)

Station Modes	Hh
Channel 1	`6300 - 6316 MHz USB RCP`
Channel 2	`6316 - 6332 MHz USB RCP`
Channel 3	`6642 - 6658 MHz USB LCP`
Channel 4	`6658 - 6674 MHz USB LCP`
Bandwidth	16 MHz
DAS Mode	Mark5

Mode changes:
324 23:00:00 v255w.5cm-icrf
324 23:51:00 v255w.5cm
325 02:56:00 v255w.5cm-icrf
325 03:45:00 v255w.5cm
325 06:55:00 v255w.5cm-icrf
325 07:45:00 v255w.5cm
325 10:56:00 v255w.5cm-icrf
325 11:55:00 v255w.5cm
325 14:56:00 v255w.5cm-icrf
325 15:45:00 v255w.5cm
325 18:56:00 v255w.5cm-icrf
325 19:51:00 v255w.5cm
325 22:15:00 v255w.5cm-icrf

Ftp: ftp://ftp.atnf.csiro.au/pub/people/vlbi/v255/v255w

Comments:

At Cd Ho Mp: Dual frequency setup required. Will need special DAS setup

The purpose of these observations is to obtain a proper motion/parallax measurement for G339.884-1.259, G339.681-1.208 and G339.682-1.207, G287.371+0.644, G291.274-0.709 and G316.640-0.087, G316.811-0.057.

The maser emission is at approximately:
6668.52 (G287.37)
6669.12 (G291.27)
6668.90 (G316.64)
6669.46 (G316.81)
6669.28 (G339.884)
6669.05 (G339.68)

During the ICRF runs we have sometimes had to exclude certain antennas from observations of some sources in order to get a good spread of azimuths and elevations. Warkworth 30m is not included in any of the ICRF observations because of the limited front-end bandwidth currently available.

Observing comments for each antenna:

Hobart, Ceduna :

The level into IF#1 will change significantly between the two setups. Set the level into the DAS so that it is within range for both setups. Setup the system temperature measurement so that it works for both IFs for the v255w.5cm setup. Please don't change the attenuation into the DAS when the setup changes as that may change the delay.

Mopra :

Note the use of the dual sideband vsop profile. Only the lower sideband should be selected for transfer. The basic method and frequencies for this experiment are the same as for all of the recent v255 experiments (at least the last 3 years). As for the earlier experiments for the ICRF observations it is 2 IFs with different polarisations. The times for the setup (mode) changes are given above.

ATCA :

For the ATCA please phase-up antennas CA01 through CA05 for this experiment.

Setup as for a 2p-4IF experiment (dual DAS with huygens cable for entire experiment) with DAS1 tuned to the lower frequency and DAS2 to the upper frequency. Use the feature in cdisko version 4 to automate the changes of channel selection as per the following table. v255w.5cm Channels 5-8 v255w.5cm-icrf Channels 1,2,7,8

During phase-referencing observations, ATCA needs to be re-phased approximately every hour on the following sources: 1921-293
0537-441
J1101-6325
J1417-5950

The times have been identified with the AUTOPHASE_DETERMINE command in v255w.key.