Observing Procedures

Dept of Astrophysics
University of NSW
Sydney

Hot Molecular Core Project

Frequencies, schedule files and procedures for the Hot Cores project.

Observing Procedure

For an operations overview in a checklist format see the observing procedure page. Here are some General tips.

There are over 80 sources to observe in several lines. Your job is to try and make the most efficient use of the time available to get good data.
Pick a line and observe a block of sources in that line. Try to plan your observations so that you observe sources while they are between 45 and 90 degrees elevation.
Be aware that the pointing model deteriorates when the telescope tracks across the zenith and when slewing more than 10 degrees.
When running sio_point check in camon that your pointing values are taking effect - use the /pp page. It should update to reflect the changes within ~10s.
If a line is visible on SPD during the first integration cycle and the signal to noise is strong then cut back on the number of repeats of the sched file as time is precious.
If you get a strong absorption trough in the spectrum coming in it is likely there is emission in the off source position. Stop, close the file and start the observation again with a schedule file like onof1d which has a larger throw. Note this in the log.
Look frequently at the weather pages and check on the conditions outside the window to make judgements on the frequency of Tsys measurements. The concam webpage gives you a live view of the sky outside.
Once or twice per week observe a flux calibrator source in each of the lines you have observed. The calibrators are in the catalog file 'cals.cat'
Don't forget to close the data file after each source!

Lines and Frequencies

In no particular order:

Line	Frequency Tuner (GHz)	Frequency TCS GUI (MHz)	Comments
SiO maser	86.243442	86243.442	Pointing Frequency
CH₃CN_a	91.987094	91975	Moved 40 km/s to red.
HCN	88.631847	88631.847
HCO⁺	89.188518	89188.518
HNC	90.665432	90665.432
H¹³CO⁺	86.754294	86754.294
N2H+	93.173404	93173.404
CH3OH	96.74142	96741.42
CH₃CN_b	110.383552	110369	Moved 40 km/s to red (to centre lines in bandpass).
SiO thermal	86.846998	86846.998	Not currently in the list for 2003

Source Catalogs

Catalog files in a format readable by TCS:

Catalog File	Directory on Warrum	Comment
cat.2003	/c/observer/unsw_hc	Full source list for the Hot Core Project
cat.SiO	/c/observer/unsw_hc	Pointing sources used for the Hot Core Project
cals.cat	/c/observer/unsw_hc	the 3 callibrator sources
cat.SiO_sest	/c/observer/unsw_hc/	Full pointing source catalog
mastercat.txt	/c/observer/unsw_hc	Master observation record file

Catalog files are delimited by spaces and contains the following columns: name, ra, dec, J2000, vlsr.

Directories

Useful directories to know.

Directory	Computer	Use
/c/data/MPCCC_1/corr/dat/	Warrum	Raw .RPF data files files are written here. Crosslinked between mpccc and warrum.
obs$0:[multi.sched]	Mopra	Schedule files. Use 'schedput' to ftp over new files.
/c/observer/users/	Warrum	User Directories
/c/observer/unsw_hc/	Warrum	Hot core user directory
obs$0:[multi.point]	Mopra	sio_point looks for raw .RPF files in this directory

Schedule Files

The number of times to repeats the schedule file is not included within the schedule file for flexability reasons. Always remember to set the "repeats" box in the TCS GUI to the value indicated below.

Schedule file	Correlator Config	Cycles Scans	Repeats	Mode	Ref Posn	Use
pnt_test2	ac_64_1024_2f	2 / 6	1	5pt cross	+15m lat	quick pointing
pnt_test3	ac_64_1024_2f	3 / 6	1	5pt cross	+15m lat	more sensitive pointing
onof10m	ac_64_1024_2	4	Set Manually	OFF-ON	+1m long	Hot Core survey
onof2	ac_64_1024_2f	4	Set Manually	OFF-ON	-2d lat	Quick look

Total Observation time = (Cycles + 1) X 10s X Scans in Set X Repeats

Logs

Keep the log-book up to date each observing run. Record the following:

Universal Tme
Source name
RPF file name
Detection?
System Temperature (Tsys)
Pointing corrections (fx and fz calculated by sio_point) and total offsets (given in camon)
Weather conditions

Update master log as you go with details of the file names and lines observed.

Before leaving Mopra don't forget to photocopy the log to bring back to UNSW.

Data & Reduction

Many lines will be strong enough to see with in real time as the data is collected. The program SPD on Warrum is used for this purpose.

If the line is very strong and the signal to noise is good, cut the number of repeats- the time could be better used eleswhere.
Use the program DFM to reduce the data as it is being taken and record wheather a detection was made or not.
At the end of the observing run burn all data to disk and backup to the user directory on Minos.

Page created by Cormac Purcell and maintained by Nadia Lo. If you have any comments and suggestions, please direct your email to nlo@phys.unsw.edu.au.