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|Description||Proper motion and Parallax of Methanol Masers|
|DAS Mode||vsop.pro (telescope)|
The beginning and end of the experiment will use the following setup:
|Skyfreq IFP#1||6316.00 MHz|
|Skyfreq IFP#2||6656.00 MHz|
The purpose of these observations is to obtain the second epoch for proper motion/parallax observations of the methanol maser source G9.62+0.20 and the first epoch for G8.68-0.37. We are using the same observing mode as for v255a (March 08) and will observe both masers and phase calibrators with 2×16 MHz bandpasses, but the correlator output will be high spectral resolution around the masers (G9.62+0.20 should show a strong peak at a sky frequency of around 6668.3 MHz during these observations) and standard continuum for the phase reference source. The idea is to have a mode which expands the number of suitable phase reference sources available for spectral line sources. The frequencies are nearly the same as for March 2008, but shifted by 1 MHz.
The experiment has 5 distinct sections, minor setup changes are required between 02:00 and 02:20 then at 05:57:30, 14:36:00 and 15:24:40 UT
During the ICRF runs we have sometimes had to exclude certain antennas (particularly Parkes & Hart) from observations of some sources in order to get a good spread of azimuths and elevations.
The 4 x 16 MHz bandpass setup will require feeding two separate LOs into IFP#1 and #2 on the DAS/frequency translator and splitting the LCP signal so that is feed into both sides. For Hobart the LOs should be set to 468 MHz (IFP#1) and 808 MHz (IFP#2) for the 4 x 16 MHz setup and 808 MHz for the 2 x 16 MHz setup. For Ceduna, if you set the agilent to 11.1 GHz rather than 11.4 GHz, then you can use the same LOs as at Hobart.
Scheduled from 1102 - 1628 UT. Hart should observe with the dual polarization 2 x 16 MHz bandpass setup throughout, even during the final ICRF session when the other antennas change to single frequency 4 x 16 MHz setup.
Cable up with the Huygens cable for the entire experiment. Observe with dual DAS setup using 2 DASes for the 4 x 16 MHz setups and 1 for the dual polarization 2 x 16 MHz setup. Record using the following cdisko channel selections at the appropriate time ranges. Stop the recorder in between! At Parkes you will have to change the frequency manually running for example (in a pavo xterm)
> lorun @2008_METH-split.cmd
|UT||Channel selection||Parkes Frequency setup|
ATCA will have to cacal at 6.3/6.7 GHz and 6.7/6.7 GHz before the experiment. Note “catie” should be setup for Rcp/Lcp (Lcp is selected in cdisko)
During the first 20 minutes we will need to calibrate the delay between the two ATNF DAS, and the delay between Hobart/Ceduna in dual pol and single pol mode. The following modes will need to be used to calibrate these.
Everyone records with a dual polarisation/6.7 GHz setup. ATNF records at 512 Mbps, ie Huygens/Channel 1-8 in cdisko with DAS1 and DAS2
Hobart and Ceduna cable up with LCP into both IFP, but remain at 6.7 GHz. Pks/ATCA/Mop record chans 1-4.
Hobart and Ceduna retune IFP#1 to 6316 MHz. Parkes/Mopra/ATCA run with DAS#1 centered at 6316 and DAS#2 at 6656 MHz and record Chan 3,4,7,8 in cdisko. Parkes will have to
lorun. ATCA and Mopra have the frequency change built into the schedule.
|Time (UT)||Ho/Cd||At/Pa/Mp||ATNF Channels||Parkes lorun|
|02:00-02:07||Dual Pol||Dual Pol||1-8||2008Aug_METH.cmd|
|02:07-02:15||Lcp only 6.7/6.7 GHz||Dual Pol||1-4||2008Aug_METH.cmd|
|02:15-02:20||Lcp only 6.3/6.7 GHz||Lcp only 6.3/6.7 GHz||1-4||2008Aug_METH-split.cmd|