Research School of Astronomy & Astrophysics

INSTRUMENT AND SOFTWARE DEVELOPMENT

MACHO Data Pipeline

The MACHO (Massive Astronomical Compact Halo Objects) data pipeline continues to be stable. Axelrod, with Smillie, has been working to extend its capabilities to allow fully robotic operation of the MSO 50-inch telescope. This will allow the telescope to be run at low cost after MACHO observations conclude at the end of 1999.

Wide Field Imager

In collaboration with the Anglo-Australian Observatory, the University of Melbourne and Auspace, the RSAA is developing an instrument known as the Wide Field Imager (WFI). WFI will be used on both the SSO 1m telescope and on the 3.9m Anglo-Australian Telescope. The RSAA project scientist is Dr G Da Costa. The heart of the WFI will be a mosaic of 8 4096 x 2048 pixel CCDs, arranged to produce images 8192 x 8192 pixels in size. On the SSO 1m telescope this will allow an area of sky to be imaged that is six times larger than is currently possible with single CCDs. During the report year the fabrication of the WFI dewar in the RSAA workshop was completed. The dewar was then shipped to GL Scientific in Honolulu, Hawaii, who have been contracted to assemble and mount the CCD mosaic. At the present time we are awaiting delivery to Hawaii from MIT-Lincoln Labs of sufficient CCDs to complete the array. Considerable progress has also being made with the development of the software and hardware to control the mosaic and to deal with the large volume of data WFI will produce. The filter and shutter mechanisms, guiding arrangements, corrector lens assemblies, support structure, etc, required for use of WFI on the SSO 1m telescope have been designed and are currently being constructed in the RSAA workshops. First images with WFI should be obtained during the second quarter of 1999, subject to the delivery of the CCDs.

Figure 11: An engineering drawing of WFI as it will appear on the ANU 1m telescope. From the left the components are the corrector lens assembly and filter wheel and shutter mechanisms, dewar mount plate and the WFI dewar with attached CCD controllers, power supplies and water cooling system. The water cooling system ensures excessive heat is not generated in the telescope dome which would otherwise degrade the atmospheric seeing.

Annual Report 1998

Planetary Nebula Spectrograph

Freeman is principal investigator of an international team constructing a dedicated slitless spectrograph for detecting extragalactic planetary nebulae and measuring their velocities in a single observation. This Planetary Nebula Spectrograph is designed for use at several 4-m telescopes. The partners in this project are the Osservatorio di Capodimonte (Naples), Kapteyn Laboratory (Groningen), ESO, University of Munich, AAO and RSAA.

Algorithms

Kalnajs implemented new and fast algorithms for solving Abel's integral equation, which occurs in many astronomical contexts, and for calculating rotation curves from spheroidal mass distributions.

2.3 m Acquisition TV Upgrade

It has long been realised that the DBS on the 2.3 m telescope was capable of measuring low-resolution spectra of objects that were too faint to be seen on the acquisition TV system. This acquisition TV was replaced during 1998. Various commercial CCD cameras and control software designed for amateurs were investigated by McGregor and Conroy. The system chosen uses an Apogee AP7 camera and MaxIm CCD software. The Apogee AP7 camera uses a science grade 512x512 pixel back-side illuminated SITe CCD with a peak quantum efficiency of 85%. The DBS slit viewing optics were changed to provide a scale of 0.36 arcsec/pixel and a field-of-view which includes the full DBS slit width and ~ 180 arcsec of the 400 arcsec total length of the slit, larger than with the old system. The original MaxIm CCD software was modified and enhanced by the supplier to permit convenient interaction with the 2.3 m telescope system and to cater for more demanding user requirements. The new acquisition system has met with widespread user approval, and has allowed several new observing programs to commence on the telescope. Acquisition of objects as faint as B = 21.5 mag in 1.4 arcsec seeing has been reported.

Antarctic Astronomy Program

The development of the ADIMM/GMOUNT site testing system has past a number of crucial milestones in 1998. In January 1998 two Stromlo staff travelled to the South Pole, Brett McLinden and Ralph Sutherland. At the pole tests were carried out on the TMOUNT system and it was found to be in working order. The TMOUNT failure in 1997 was probably due to electronic failure in external systems. GTower vibration levels, which were suspected of being too large, were determined with laser tests. The tests ruled out large vibrations and the GTower seems to be functioning nominally.

The ADIMM telescope and camera system has become essentially fully operational in 1998, with only some minor noise problems and software refinement remaining. The GMOUNT mechanics are complete and the electronic systems are nearing completion.

In 1998 UNSW JACARA systems at the South Pole obtained mid-infrared observations of the sky brightness (the MISM instrument) before a power failure halted observations at around day 170. The power failure in 1998 did not cause major damage to the AASTO and the power unit was refurbished in the summer of 1998/1999. These mid-IR observations showed that when the sky is free of cloud (~60% of the time) the sky brightness is around 10 Jy arcsec^-2 in the mid-IR windows at 8 and 11 microns. Under moderate cloud conditions it can be 30-100 Jy arcsec^-2, and around 40% of the time it is cloudy. Figure 12 shows the 10.2-10.6 micron Mid IR window sky brightness measured at the South Pole in 1998.

Research School of Astronomy & Astrophysics

Figure 12: MISM Sky measurements from Chamberlain (Grad. Dip. Thesis, Dept. Astrophysics, UNSW 1998)

At a JACARA meeting in 1998 it was decided to not send the marginally completed ADIMM/GMOUNT system to the South Pole for Summer 1999 and completion has been deferred until 1999 and direct shipment to Dome C in Summer 1999-2000. During 1999 it is planned to operate the AFOS/ADIMM/GMOUNT system for an extended period of time at Mount Stromlo prior to shipping to Dome C. The UNSW AFOS and Mid and Near-IR sky monitor instruments (MISM and NISM) will also be deployed at Dome-C along with a SODAR sonic atmospheric turbulence detector. The Mid-IR, Near-IR and SODAR instruments will operate at South Pole for 1999.

Gemini Near-Infrared Coronagraph/Imager (NICI)

MSSSO led a consortium of Australian and international institutions with McGregor as Project Scientist in responding to the International Gemini Project Office Announcement of Opportunity for the Conceptual Design Study of a near-infrared coronagraph/imager. The coronagraph/imager is to be commissioned on the Gemini South telescope and will be used with the laser guide star adaptive optics system on that telescope. Consortium institutions joining ANU were the University of New South Wales, the Anglo-Australian Observatory, the University of Sydney, and the Jet Propulsion Laboratory from USA. The consortium proposed to execute a conceptual design study of an instrument named NICI. It was proposed that NICI be capable of direct and coronagraphic imaging, narrow-band imaging through a cryogenic Fabry-Perot, polarimetric imaging, and grism spectroscopy. The Gemini Instrument Forum at its September 1998 meeting recommended funding the MSSSO consortium design study. However, NASA funds were allocated to a USA group to build this instrument before the November 1998 Gemini Board meeting when final approval was to be considered.