Australia Telescope Users Committee

Report to the Director on the meeting held at the Australia
Telescope National Facility, Epping NSW on 19 November 1997

and

response from the ATNF Director

ATUC Report to the Director ATNF and ATNF Director's response

1. ATUC notes the inconsistency in the documentation defining the high-frequency end of the band for the ATCA 3mm receivers. We recommend a minimum window of 85 to 100 GHz, so as to include the three most important lines.

Response:
The upper end of the band is still poorly defined as it depends on what is achievable with the technology. Certainly, 85-100 GHz is a good target and probably achievable. We will review the documentation shortly and update and clarify it to reflect this.

2. ATUC notes the importance of establishing a set of calibrators suitable for mm ATCA observations. We suggest that targeted observations of known sources should take place before a blind survey.

Response:
Bob Sault has been investigating this problem an notes that:
Phase calibrators at mm wavelengths are obviously important, both for fast switching as well as conventional slow switching. The finer the calibrator grid the better. It is desirable to get a grid finer than the current ATCA calibrator list. Getting a fine calibrator list might also be quite important for calibration schemes involving the proposed water vapour radiometers. Being able to connect the phase between a calibrator and the source with the radiometer approach is something taht continues to allude attempts to date. Nearby calibrators, low spill-over and a stabel receiver are the ways to solve this.

I know of no realistic way to find calibrators at mm wavelengths other than to follow up cm detections. The primary beams are just too small. So this is what we will have to do. Mopra and SEST are not appropriate instruments to do this with as they do not have the continuum stability at 3.5mm to do the job with ease. NRAO's MMA project is not currently pursuing anything along these lines. So we will have to wait until we have at least some higher frequency receivers before we start to follow up the Tasker/Wright/McConnell ATCA observations of PMN survey sources.

3. ATUC accepts that some form of flexible scheduling for the ATCA is essential during some part of the year, once mm operations commence.

We recommend that there should be a forum to discuss this issue. Points to consider include:
i) whether there should be priority programmes to optimise the scientific output;
ii) whether proposals for large backup projects at cm wavelengths should be solicited from the community.

Response:
A forum to discuss this would be an excellent idea, perhaps in conjunction with a future ATUC meeting. It may be more efficient to defer this until more experience with flexible scheduling has been gained at other observatories.

4. ATUC is divided on whether resurfacing should be done first at Mopra or at Narrabri.

Response:
Decision has been made to resurface ATCA antennas first.

5. With regard to the N-S spur, ATUC recommends that the available railway track associated with the 6-km antenna be used, if proved cost effective. In the short term, having three mobile antennas for the N-S spur is acceptable. A complete shutdown period for ATCA will probably prove to be the most efficient way to proceed, but this should be minimised.

Response:
OK

6. Providing that at least some part of the 13cm band is useable, ATUC recommends that the upgrades at this wavelength should proceed. We recommend that additional correlator configurations at narrower bandwidths be made available. If there is a choice, we suggest optimisation at the high frequency end of the band.

Response:
Some additional correlator configurations have recently been made available with a second frequency of 64 MHz instead of 128 MHz, which may be useful in parts of the 13cm band badly affected by RFI. (The full list of configurations currently available is in the WWW version of the ATCA Users Guide). Inquiries concerning the possibility of additional specific configurations should be directed to Warwick Wilson (wwilson@atnf.csiro.au). The optimisation of the new 13cm receiver system is still under active study and the suggestion is noted.

7. ATUC recommends that the process for release of archival data be clarified and enforced.

Response:
New wording agreed by TAC is:
``Archived Data from all ATNF facilities will be available to other users on request 18 months after the end of an observation, unless a special case for extended proprietary rights is accepted by the TAC. In the case of PhD students all requests for data, before submission of the thesis, must be approved by the supervisor.

The end of an observation is defined by the last set of observations requested, either in the original proposal, or in a direct extension of the original proposal. The ATNF will notify the PI of the original observing team if possible.

Approved archival data requests to be publicly available.''

The above policy is that preferred by the TAC, however the ATNF Astro Group have argued that the PhD student rider should be broadened to state: ``In the case of PhD students all requests for data, before submission of the theis, must be approved by the supervisors, and student.''

8. ATUC recognises the scientific value of the PTI. We accept that a transition to the S2 system is necessary, but recommend that adequate resources be devoted to assist users in this transition.

Response:
We have transferred the funds saved from the PTI to employing students to work on making the S2 more user-friendly and we are also looking at other ways of making it more user-friendly. Dave Jauncey will report on this at the ATUC meeting.

9. ATUC is satisfied with sub-day scheduling at Parkes. However, we recommend that the format of the observing schedules for all the telescopes, as available on the WWW, be reviewed.

Response:
Marc Price, OIC Parkes, replied that ``We have changed the format of the Parkes Observatory schedule on the Web. This now shows clearly the assignment of the telescope in blocks for each day. We use only local civil time on the schedule. We would welcome comments on the format from any of our users.''

10. ATUC recommends that a distinction be made in the ATCA schedule between "maintenance time" and "unallocated time", and that as a trial the latter be allocated for the next two terms at the discretion of the OIC.

Response:
This change has now been made and Dave McConnell will discuss some of the implications at the ATUC meeting.

Ref.: EGP: 40_98, 18 February 1998