ATNF VLBI Wiki

The CASS director Phil Diamond addressed the meeting and discussed the future for the LBA and the reason for the VLBA arrangements.

The LBA has been making great progress ˆàwith the inclusion of many new antennas, bringing the total number to 8-11 telescopes. These include the 2 new 12m AuScope antennas, the Warkworth 12m antenna in NZ (and a 30m under refurbishment), and the ASKAP antennas at the MRO. The future of Mopra will be known by June. And there are efforts to get better access to the Tid 70m antenna. Proposal pressure is higher than ever (26 last round) and may even need an expansion of observing capabilities with the LBA.

The VLBA is the premier VLBI instrument operating today but it has been under funding pressure following NSF reviews. In February 2011, a meeting of all institutions around the world with interest in VLBI ˆàwas held in Socorro to discuss the future of the VLBA. There was strong desire to keep the VLBA operating and willingness by most institutions to make some financial contributions towards this goal. A strategic decision was made by the CASS director to also contribute to this effort. A contribution of $100k per year for 2 years was promised by CASS, with a complementary Australian contribution of $25k x 2 years by ICRAR. For many institutions, such contributions were only possible if guaranteed time was made available on the VLBA. Hence, the decision was made that all contributors will have some guaranteed VLBA time, commensurate with their contribution, even though this is against the traditional open-skies policy of the VLBA. Under these arrangements, Australia will get 62.5 hours per year on the VLBA for the next 2 years.

Arrangements of how this time will be allocated and managed have not yet been finalised with NRAO. This is the first meeting to consider this issue within Australia and to define a way to proceed. The community was invited to contribute suggestions and brief proposals on how to utilise this time.

Five contributions were submitted via email (comprising 7 programs) and another 3 were contributed at the meeting. Note that most proposers did not wish to make the contents of the proposals public at this time. A summary is given in the table below, with only the PIs names and band and times requested.

Table of possible proposals

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Note that the total time proposed is at least 2 times of what is offered and potentially much more as some proposals can utilise the whole available time.

A discussion followed whether to organise a single proposal from Australia for the full 62.5 hrs/year OR many smaller proposals. Via a show of hands there was a slim majority in favour of smaller individual proposals.

A discussion followed on how to handle the allocation of this time. Three possible models were suggested:

1. ˆàGroup meeting: PIs get together via email to reach a consensus on the 62.5 hours per year.
2. Organise a Mini-TAC (Steven; Phil; Tasso) and get full VLBA proposals
3. Proposers provide more information publicly.

ACTION: It was decided that at this stage the group of PIs so far may attempt to reach some consensus between themselves. These notes and table will be made public on the wiki and sent to all PIs in the table. Tasso will act as coordinator and the group will have 1 month to reach some consensus.

NOTE 1: The full process is expected to take 2-3 months and this only the start. There is no intention to exclude anyone and if there are other proposals from the community they will also be considered.

NOTE 2: Clarification will be sought from NRAO on conditions for this access. It is expected that normal VLBA policies on data access and proprietary periods will apply but this needs to be confirmed.

The issues are in active discussion with NRAO and an announcement would be made to the community when negotiations have been concluded.