Minutes: Northern Multibeam Working Group meeting, Mon 15th October 2001

Those present: Peter J. Boyce, Michael J. Disney, Diego Garcia, Marco Grossi, Virginia A. Kilborn, Robert Hugh Lang, Robert F. Minchin

14.05 the meeting began

Apologies: Christine Jordan

Item 1. Computing / Software

It was reported that the latest versions of gridzilla and livedata are working at Jodrell Bank. Whilst both also work at Cardiff, livedata is prone to frequent crashes.

VAK considered that we have sufficient disk space at Jodrell for the upcoming observing run.

PJB suggested that we try to reduce the data from the summer 2000 drift scan experiment. RFM agreed to try to get this data onto disk in Cardiff in the near future.

Item 2. Hardware/RFI

On his recent visit to Jodrell Bank, RHL tested the hardware associated with the project and reports no problems.

RHL and VAK reported on the current situation with regard to RFI. RHL reports that Jodrell hope to have 7 RFI cages ready in time for the Dec 2001 observing run. However, this is still some doubt about the effectiveness of these at eliminating the RFI. RHL pointed out we can only properly determine this by doing real observations with the Lovell.

VAK reported that she and Ant Holloway had tested every PC and Sparc Station at Jodrell Bank (including the Visitors' Centre). They concluded that around 60 computers need disabling during the observing run (about half the total number on site). The intention is to mark those to be disabled with red stickers and to give lots of pre-publicity to their upcoming disablement. We will have to police these machines throughout the run.

Item 3. Dec 2001 Observing Run

VAK reported that, according to Andrew Lyne, the telescope upgrade is not going to plan and there is a chance we will not be able to start observing as scheduled. If we cannot start before Christmas then the probability is that we will get no observing time this "term" although we may then get a longer run at a later stage.

VAK and RHL will be around Jodrell Bank throughout the observing run. PJB, RFM and MG each agreed to observe for a few days during the run.

PJB pointed out that, provided everything works okay, we should have enough time during the run to observe another 10 or so 8degx8deg cubes. PJB and RFM proposed that we should continue to sample the Super-galactic plane rather than trying to complete a whole new dec strip. The suggested strategy was to complete one cube each at p58, p50, p42, p34 and p26 so as to form a "bridge" between our p66 cube around M81 and the HIPASS cubes up at dec=25deg at the high dec end of the Virgo cluster. We should also work on a similar set of cubes offset (roughly) by 12hr in RA. This general approach was agreed by the Working Group.

Item 4. Diego Garcia

PJB proposed that Diego Garcia should become a member of the Working Group. Robert Minchin seconded this. His membership was unanimously agreed upon.

Item 5. JKT Observing Run, Jan 2002

DG is to be trained as a an observer on this run. PJB said he could go on this run if necessary. RFM also expressed his possible interest in undertaking to train DG. This matter will be resolved between PJB and RFM.

Item 6. HIJASS/HIPASS Relationship

MJD expressed dissatisfaction with the way in which the M81 paper had been submitted and accepted without any reference to the HIPASS team. He pointed out that HIJASS is the northern counterpart to HIPASS and that HIPASS members should be given a chance to contribute and be associated with HIJASS papers. He had emailed certain key members of the HIPASS team and these had re-assured him that they were not unduly concerned to be omitted from the M81 paper. In future MJD will send draft papers to these key HIPASS team members to ascertain whether they have an interest in being involved in HIJASS science.

Item 7. Science

There was a general discussion about the future publication aims of the Group. It was agreed that the next HIJASS paper should contain a detailed description of the project and the scientific motivations behind it. Included should also be some early results from the follow-up program. This paper should also act as an introduction to a "HIJASS Catalog". The data in the catalogue itself will be web-based. PJB and RFM outlined a strategy for creating such a catalog using a combination of eyeball searches and RFM's automated finder. The issue of whether the positions of potentially interesting objects should be published was discussed. It was generally felt that this need not be harmful provided the catalog paper was published and, hence, these sources clearly identified in the literature as having been discovered by HIJASS. PJB undertook to work on a Catalog and the accompanying paper. It was resolved that we should seek to register the domain www.hijass.com for the project (MJD undertook to pay).

Item 8. Any Other Business

MJD pointed out that we would be away from Oct 19th until April 2002. He will firstly be in America and then (from mid-November) in Australia (Sydney).

MJD briefly discussed the problem of trying to detect broadline galaxies in HIPASS/HIJASS data. DG had found weak HI emission in HIJASS data from a number of edge on galaxies. These objects had not been selected by eyeball searches of the cubes, suggesting that many other broadline objects may have been missed by such searches.

MJD suggested that we should attempt to observe a cube at higher velocity resolution to see if this improves our ability to detect very broadline objects. It was generally agreed that this was a good idea and further thought will be given to the best way to pursue this aim.

16.10 The meeting closed