------------------------------------------------------------------------ Announcements of Opportunity for Observations with 6dF ------------------------------------------------------------------------ ***Deadline 15th October 2000*** 1. CALL FOR PROPOSALS FOR ADDITIONAL TARGETS FOR THE 6dF GALAXY REDSHIFT SURVEY The Anglo-Australian Observatory (AAO) is to undertake a redshift survey of the southern sky using the Six-Degree Field multifibre spectroscopy system (6dF) on the UK Schmidt Telescope (UKST). 6dF is now nearing completion at the AAO's Epping laboratory. It consists of 150x100um fibres (projecting to 6.7 arcsec diameter on the sky), which are positioned off-line by an r-theta robot across a circular field with diameter 6 degrees. Once the 6dF field-plate is loaded in the telescope, the fibres feed a floor-mounted spectrograph equipped with a Marconi CCD chip of very high QE. Sources cannot be observed at separations less than 5 arcmin; this and other fibring constraints will limit the completeness in any one field to around 90%. The z-survey is to start in April 2001, and is expected to take about 2 years, using 75% of scheduled time on the UKST. The survey will cover the entire southern sky with |b|>10 degrees. The primary target list will be galaxies without already-measured redshifts selected from 2MASS, DENIS, APM and SuperCosmos data. The galaxy sample will be complete to total magnitudes close to K'=12.8, H=13.5, J=14.1, I=15.0, r_F=15.5, b_J=16.5. The data will be non-proprietary, and will be made available on-line via the Wide-Field Astronomy Unit (WFAU) of Edinburgh University in periodic data releases six to twelve months after observation. The primary target list amounts to approximately 100,000 galaxies. The 6dF Science Advisory Group (6dFSAG) has recommended that there is scope for up to an additional 20,000 objects to be observed along with the main sample. These additional targets will be of two types: (1) about 10,000 will be `secondary' targets for which the survey will attempt to achieve the highest levels of sample completeness and uniform sky-coverage consistent with the goals of the primary survey. These targets may be all-sky or in selected regions; (2) about 10,000 will be `serendipitous' targets observed using spare fibres in under-dense fields where not all fibres are allocated to primary or secondary targets due to fibring restrictions. These will be spread over the whole survey area and cannot be guaranteed to achieve complete samples or uniform coverage. Applications are now invited to determine the best additional samples that can be accommodated on scientific and technical grounds in these two categories. These additional targets will be observed, reduced and the data made publicly available along with the primary sample. The survey observations will consist of approximately 1-hour integrations on fields that are chosen to tile the final target list as efficiently as possible. (It is likely that most of the area of the survey will be covered at least twice.) The spectral coverage will be within the range 3900A-7500A at about 3A/pixel, with a FHWM resolution of 7A or better. The final adopted spectral coverage and resolution will depend on results obtained during commissioning together with the decision on including the peculiar-velocity survey (see below) and the needs of highly-ranked additional-target proposals. It is anticipated that a S/N of 10 per pixel will be reached for objects with B=17 and R=15.5 in median conditions. As well as the z-survey, there will also be a v-survey of 15,000 peculiar velocities, Targets will be early-type galaxies in about 300 over-dense fields. Currently, it is expected that this will be started later than the z-survey and will be completed by 2004. There is, however, the possibility that the z- and v-surveys could be merged, so that they proceed concurrently. This will only take place if the actual FWHM resolution of the spectrograph in z-survey mode achieves its theoretical value of 5A-6A, and will not be known until the commissioning of the new 6dF detector has been completed later in the year. Merging the two surveys would significantly increase the number of additional targets that can be accommodated, possibly by a factor of two. If, in the event, the v-survey has to be undertaken separately, the instrumental setup will give a spectral range of 4700A-5500A at 0.8A/pixel; integrations will be about 4 hours. In these fields there are likely to be of order 50-100 spare fibres, allowing another 20,000 additional targets to be observed over the course of the peculiar velocity survey. In that event, proposals for additional targets will be sought at a later date. For further information, see the WWW pages at http://www.mso.anu.edu.au/colless/6dF, and the guidelines at http://www.roe.ac.uk/wfau/6df/6df.html Proposals for the z-survey additional targets should be submitted on the 6dF proposal form: http://www.roe.ac.uk/wfau/6df/6df_form.html by 15th October 2000. Applications should specify the number of targets, the region of sky of interest, and whether complete or serendipitous coverage is required. They should also include a full scientific case and relevant technical details. Applications will be technically assessed by the AAO and the 6dFSAG, and scientifically ranked by the UKST TAC during November. The science case for all applications, and the target lists for any successful applications, will be made publicly available. Applicants should be prepared to submit a source list, with arcsecond-precision positions, by 31 December 2000. Further information about possibilities for additional and serendipitous targets can be obtained from Will Saunders . ------------------------------------------------------------------------ 2. CALL FOR 6dF SHARED-RISK COMMISSIONING-TIME PROPOSALS (JAN-MAR 2001) AND CALL FOR 6dF OPEN-TIME PROPOSALS (APR-JUL 2001) It is expected that 6dF commissioning will start on the UKST during December 2000. A three-month commissioning period has been agreed, with the main 6dF Galaxy Survey scheduled to begin in April 2001. Depending on progress during the commissioning phase, there is the possibility that significant ammounts of 6dF commissioning-time could be used to perform scientific observations on a best-efforts basis. Optimum efficiency and performance may not be available during this phase. However, projects requiring observations of a few hundred objects over several 6dF fields should be able to be attempted. Such commissioning time is likely to cover the period Jan-Mar 2001. The AAO has recommended to the TACs (the two Schmidt Telescope Panels) that they allocate a total of 12 nights (6 nights from each panel) to carry out 6dF observations in service mode during this period. This will be in addition to bright- and dark-time commissioning nights allocated from Director's time. The telescope will revert to its photographic programme in the event of the 6dF schedule not proceeding as planned. All observations will be carried out in service mode by the 6dF commissioning team. Science observations will be chosen at appropriate points during commissioning on the basis of scientific ranking by the STP and compatibility with the functionality of 6dF at the time (e.g. fibre reconfiguration time). Every attempt will be made by the commissioning team to fulfil the notional 12 nights allocated to science during the period. To provide full accountability to the STP and user community, the commissioning team will keep an accurate record of the split between commissioning and science time. However, the science time should be viewed as `shared-risk' by proposers and STP alike. In the event that essential commissioning encroaches on this time, there can be no guaranteed pay-back to either the STP or proposers. Standard 6dF open-time (at the level of 15% of overall UKST time) will be available for community use from Apr-Jul 2001 (i.e. the remainder of Semester 01A) and on the usual 6-monthly cycle thereafter. Thus, approximately 10 nights of open-time will be available in Semester 01A. Astronomers interested in either the commissioning time or general open-time are requested to complete the provisional 6dF general application form which can be found at: http://www.roe.ac.uk/wfau/6df/6df_form.html clearly stating whether they are requesting commissioning-time or open-time. The deadline for both commissioning applications (Jan-Mar) and those for the remainder of Semester 01A (Apr-Jul) is 15th October 2000. Interested parties can contact Quentin Parker , Will Saunders or Fred Watson directly for further information, instrumental configurations, etc., and can refer to the www at: http://www.mso.anu.edu.au/colless/6dF, and the guidelines at http://www.roe.ac.uk/wfau/6df/6df.html ------------------------------------------------------------------------