NEWS FROM DRAO

 

Christmas was an especially happy season for DRAO, with the news that the senior management of NRC has decided that our Observatory is not to be closed in March 2001, but is to continue (for the announcement, see the December 1997 issue of Cassiopeia). We are now starting to plan that longer future, and will involve our community heavily as we make plans for the Synthesis Telescope after March 2000 (when it completes observations for the present phase of the Canadian Galactic Plane Survey - the CGPS).

 

CGPS observing routines are well established, and data reduction techniques are approaching the same state, allowing us to focus more on research with the data. Observations for the CGPS are rolling along, with the Synthesis Telescope working like a well-oiled machine. Over half the area projected for observation at DRAO has now been observed with the Synthesis Telescope. Data reduction is (not surprisingly) a little further behind. A second data release to members of the CGPS Consortium was distributed (via CD) just after Christmas; this is the first release of data which includes single-antenna information.

 

Observations of the entire survey area with the DRAO 26-m Telescope (to provide short-baseline information for the survey) are now complete, and Lloyd Higgs is working on the final corrections to these data (for telescope sidelobe responses and other small effects). More than 25,000 H I spectra were taken, and this survey is quite an undertaking in its own right.

 

The Space VLBI Correlator is a busy place. After the excitement of the first fringes from space to ground in June last year, the correlator is settling into a busy and productive everyday existence. A lot of work has gone into co-ordination of the far-flung observatories which send their data to DRAO. Brent Carlson and David Del Rizzo are working two shifts to keep pace with the data as there are currently more than 50 observations at some stage of completion. Some involve as many as eight stations, quite a trick for a six-station correlator. Natural Resources Canada, a partner in the VLBI operation, has installed a 3.5-m antenna at DRAO to be used for Geodetic GVLBI measurements. Over the summer of 1998 this system will be put through its paces by Bill Petrachenko (seconded to DRAO from NRCan). After about a year of "shakedown" at DRAO, the small antenna will be on the road every summer, making precise survey measurements of a network of sites to help refine knowledge of the reference points on which all precision surveying in Canada depends.

 

The Solar radio flux monitoring program is continuing into its sixth decade of precise and reliable measurements. The flux density is slowly climbing as we enter a new cycle of solar activity. The worldwide community of users, solar astronomers, space-weather forecasters, meteorologists and climate specialists, power companies, and satellite-communications companies (among others), counts on the data, and its reliability is a source of pride to the DRAO Operations Group.

 

Working to protect the radio astronomy allocations in the frequency spectrum is now occupying a substantial fraction of Ken Tapping's time. He reported in the last issue of Cassiopeia on the World Radio Conference held in Geneva in October and November 1997. He was in Geneva again in late February. This work is very necessary to ensure that radio astronomy has a future. Pressure on the radio spectrum will affect astronomers at both centimetre and millimetre wavelengths, and we are grateful to Ken for carrying on this battle. The work has national and international significance, with Canada playing a significant role.

 

The team working on the design of a new multi-beam spectrometer for the JCMT is approaching an important deadline, the Preliminary Design Review at DRAO in April. Specifications and design memos are being generated, and a lot of thought and testing is going into the specifications for a computer capable of handling the most ambitious observing technique, "on-the-fly" mapping, where correlation coefficients flowing from as many as 32 beams on the sky must be transformed into a spectral-line data cube. Parallel computing concepts will be necessary to cope with data rates as high as 10 Mbytes per second.

 

There is a high level of activity in the group working on the Future of Radio Astronomy. This edition of Cassiopeia includes a report from a meeting held in Sydney (Australia) in December, 1997, where it was agreed that the Square Kilometre Array must work at short centimetre wavelengths (an important requirement of Canada's astronomers). At home, a grant has been received from NRC which will kick-start detailed engineering studies of the Large Adaptive Reflector (LAR). At a meeting in Calgary in February, plans were laid to tackle the engineering work needed to establish the feasibility of the LAR. Researchers from the Universities of B.C, Alberta, Calgary, Manitoba and Toronto were there. With co-ordination from DRAO, the work will begin at once, with this phase set to end in March 1999. With a further grant from NRC, DRAO has been able to buy a set of powerful antenna-design software. Specifying and selecting this software was a complex task, which occupied Bruce Veidt for several months. It will soon be in place, and will allow research into alternative feed designs for the LAR. Incidentally, it will be made available to small companies working on antenna design. This use of the software will be in co-operation with NRC's IRAP division (Industrial Research and Assistance Progam).

 

Two graduate students, Leonid Belostotski and Anne Thorsley, both M.Sc. candidates in Electrical Engineering, are working at DRAO. Leonid is developing a local oscillator system for the Large Adaptive Reflector, and Anne is measuring the figure of the antennas of the DRAO Synthesis Telescope using holographic techniques.

 

Later this year, DRAO will be host for an international workshop entitled "New Perspectives on the Interstellar Medium", to be held at Naramata, near Penticton. This conference will be a focus for our Canadian Galactic Plane Survey research, and it will help us put the research of our Consortium into a wider perspective. The Scientific Organizing Committee is in place and the Local Organizing Committee at DRAO (chaired by Lloyd Higgs) is at work.

 

David Lacey retired from DRAO in October 1997 after more than 35 years at the Observatory. David was responsible for engineering for the 22 MHz telescope at DRAO, and then for the Synthesis Telescope. His expertise on power systems and on telescope drives and controls has been a real strength, and he gained a reputation for building things that worked. He is also an expert on the shielded rooms and enclosures that keep the electromagnetic radiation from our computers out of the sensitive receivers of our telescopes.

 

Chris Purton will be retiring at the end of March 1998. He first came to DRAO in the middle 60s, when he was a graduate student at the University of Cambridge, to work on and with the 10 MHz telescope. His work helped establish the low-frequency flux-densities of radio galaxies and quasars, an important astrophysical question at the time. He later worked for NRC in Ottawa, and was on the faculty of York University where his research interests turned to radio stars and planetary nebulae. He came back to DRAO in 1981. His recent three-year stint at the JCMT won him many accolades. He has been the Operations Manager at DRAO since 1995, and has been instrumental in developing the observing strategies and the team approach that make the operation of our telescopes so successful. He plans to continue his research at DRAO as a member of the CGPS consortium.

 

In November 1997 Erika Rohner left the DRAO staff and moved to London, Ontario, where she has taken on a very responsible administrative position in NRC's Institute for Manufacturing Technology. Erika had been at DRAO since 1975, for most of that time in charge of administrative services here. She helped DRAO staff and visitors through innumerable scrapes with bureaucracy, a great legacy of service. We wish her well in her new job.

 


                                 
Tom Landecker,
National Research Council of Canada,
Herzberg Institute of Astrophysics,
Dominion Radio Astrophysical Observatory,
Box 248, Penticton, B.C., Canada V2A 6K3
Telephone: (250) 493-2277	FAX: (250) 493-7767
       or: (250) 490-4304
E-Mail:	Tom.Landecker@hia.nrc.ca



Resources / Ressources:

The DRAO home page:

Details on the international workshop entitled "New Perspectives on the Interstellar Medium" or Nouvelles perspectives sur le milieu interstellaire can be found at