ALMA Update

1  Recent news

1.1  Construction Progress

The big news for ALMA in May was the approval of NSF's request for additional funding for ALMA by the National Science Board. This action provided the NSF Director with spending authority that covers the revised baseline cost of ALMA as approved by the ALMA Board. It was the first step to acquiring the needed additional funds; discussions with the U.S. administration and congress are yet to come. As you may recall from previous newsletters, ESO was able to approve the additional funding required for ALMA in late 2005 and the need to secure additional funds from the U.S. side has been a major preoccupation of the last six months.
In physical construction news, the outside shell of the main building at the 5000 m high site has been completed and the contract to finish the interior has been let. The contract for construction of the Operations Support Facility (OSF) at the 3300 m site, an ESO responsibility, has been approved by the ALMA Board at their June 2006 meeting. After a review of the feasibility of building a separate power station for ALMA, it has been decided to connect to the Chilean grid rather than construct and operate a stand-alone facility. Successful fringing tests using the intermediate frequency (IF) downconverters were carried out in the lab in Socorro, New Mexico, in which the IF output from two warm multiplier assemblies were passed through the backend analog and digital subsystems to the correlator where cross-correlation power spectrum and phase plots were run.
Shell - main building
Figure 1: the completed shell of the main building for the Array Operations Center for ALMA at the high site (5000 m elevation)
Dr. Paola Andreani has recently been selected to be the Manager of the European ALMA Regional Center (ARC) for ESO. Her counterpart on the North American side is Dr. John Hibbard of NRAO. Dr. Chris Carilli was recently selected to head the North American ALMA Science Center (NAASC) in Charlottesville, ( http://www.cv.nrao.edu/naasc/ ) which includes the North American ARC and which will be responsible for user support for the North American community and other aspects of ALMA operations. A major task for the North American community is securing the money for ALMA operations, which will ramp up over the next few years in preparation for Early Science observations in 2010. We took advantage of the recent AAS meeting in Calgary to have a meeting between U.S. and Canadian scientists involved in ALMA operations planning to begin to define what role Canada will play in the operations era. We will be having a series of telecons and an additional face-to-face meeting over the summer to work out the details before the U.S. operations plan is submitted to the NSF in the early fall of this year.

1.2  ALMA Science Meetings

The second world-wide meeting on "Science with the Atacama Large Millimeter Array" will be held in Madrid, Spain, on 13-16 November 2006. Registration for this meeting is open until July 1, 2006 and is limited to 250 people. The conference will cover a wide range of topics, which will include the main scientific drivers of ALMA: the formation and evolution of galaxies, the physics and chemistry of the interstellar medium, and the processes of star and planet formation. The web page for the conference, including the preliminary scientific program and registration information, is available at http://www.oan.es/alma2006/ .
Students and postdocs will be interested to know that HIA will be hosting a summer school on Submillimetre Observing Techniques, which will include talks on observing with ALMA, from 14-17 August 2006 in Victoria. Registration for this meeting is open until June 30, 2006, and information about the school can be found at http://hia-iha.nrc-cnrc.gc.ca/astroschool/ .

Chris Wilson presented an overview of the ALMA project and the types of science it will do at the CASCA meeting in Calgary. In case anyone missed the talk (it was moved from the second day to the first day to accommodate the late arrival of Jim Stone, who was the first speaker), the talk will be available on the Canadian ALMA web site at http://www.almatelescope.ca/ .

There was also a special session on ALMA at the AAS meeting in Calgary, with science talks on star formation by Doug Johnstone (HIA), nearby galaxies by Jean Turner (UCLA), and high redshift galaxies by Andrew Blain (Caltech).

2  ALMA Science Advisory Committee

The ASAC met 28-29 January, 2006, at the University of Maryland. The ASAC had three charges for that meeting: to review the progress in the science software development for ALMA; to review the plans and progress toward the scientific integration of the Atacama Compact Array into the baseline ALMA project; and to review the existing analysis on the imaging performance of the hybrid ALMA array and advise the project on whether additional work needs to be done in this area.
Regarding the science software development, the ASAC noted the continued progress by the software development teams. The fact that the major redevelopment of AIPS++ (to be renamed CASA) required for ALMA data reduction remains to be completed means that there continues to be a risk on the development path. In addition to the technical work remaining to be done, there is some concern that scientists (both expert and novice users) may be hesitant to adopt the new software given the history of the development of AIPS++. The ASAC recommended that the ALMA software team develop a plan to encourage adoption of the software as the system becomes available to science users. The ASAC also recommended that the ALMA project be 100% committed to sole use of the ALMA science software during the commissioning period and noted that it is essential that the computing resources are available to support this use.
Regarding the scientific integration of the Atacama Compact Array (ACA), the ASAC noted that there has been substantial progress in the integration of the ACA into the baseline ALMA project. The work on calibration has revealed the need for additional clarification in the calibration requirements, specifically in the area of the cross-calibration accuracy between the ACA and the 12m array. The ASAC report proposes precise definitions for this requirement and three other calibration requirements that are already in use for ALMA but are not always clearly defined. The addition of the ACA increases the number of observing modes and the ASAC recommended that the project carry out a detailed study of both the calibration and the scheduling impact of these new modes. Finally, the ASAC noted that the Design Reference Science Plan does not include projects using receiver bands 4 (125-163 GHz or 1.8-2.4 mm) or Band 8 (385-500 GHz or 0.6-0.8 mm), or detailed information for the use of the ACA, and recommended that the DRSP be updated to include this missing information.
Regarding the polarization and mosaicing performance of ALMA, the ASAC believes that having two designs for the 12m antennas should not preclude any of the Level 1 science goals for ALMA, including imaging fidelity and wide-field polarization, as long as tight control of key antenna specifications is maintained. The ASAC recommended that the Antenna or System Engineering IPT use EM modeling to estimate the beam and its sidelobes and that these results be compared to the results from holographic data and fed into further work by the Science IPT on mosaic image fidelity and wide-field polarization imaging.
On other issues, the ASAC feels that ALMA outreach and public relations need a higher profile with better coordination between the different groups involved. The ASAC recommended that a fully-integrated and properly resourced IPT be formed to ensure that ALMA has a single public face that reflects the scientific excitement and technological excellence of the project. The full ASAC report is available at http://www.alma.nrao.edu/committees/ASAC/asacreport_2006jan.pdf
John Richer (Cambridge) is the new chair of the ASAC and Lee Mundy (Maryland) is the new vice-chair. The next ASAC meeting will be held September 16-17, 2006 in Florence, Italy, where the ASAC will review the revised Commissioning and Science Verification Plan, the revised Calibration Plan, and the existing work on developing complete descriptions of the ALMA observing modes.

3  ALMA Developments in Canada

3.1  Band 3 Receiver Development

The Band 3 Receiver Development continues to keep pace with the ALMA project. Over the past three months the team has completed the testing of the first Band 3 pre-production cartridge, including the phase stability measurement. The cartridge passed its testing with flying colours and has met or exceeded all of the ALMA requirements. The team also prepared for and passed the Test Readiness Review which examined the acceptance test plan of the Band 3 cartridge to ensure that the performance characteristics can be verified. The review panel consisted of the Front End IPT leader and deputy-leader, Front End IPT systems engineer, and the project managers of the North American and European Front End Integration Centers. The review panel was satisfied with the proposed acceptance test plan prepared by the Band 3 team. Congratulations to all.
An important milestone in mixer testing at HIA has been passed with the completion of the automated mixer test set. This automation enables the team to perform noise temperature measurements of the double sideband (DSB) and sideband separating (2SB) mixers without any operator intervention. The automation substantially reduces the manpower required for the mixer testing operation and increases the accuracy and repeatability of the measurements.
Beyond the ALMA project, the Band 3 team has been drumming up business for its innovative technology. A license agreement was signed with Nanowave Technologies Inc of Toronto to manufacture and market the HIA 4-8 GHz cryogenic amplifiers for other commercial applications. HIA received a modest amount of royalty payment after the signing of the license agreement. Two customized units were sold to CEA Saclay, a French physics research laboratory in Paris, to measure shot noise levels of materials at cryogenic temperature. As well, Dr Bernard Placais and Dr. Christian Glattie from the Ecole Normale Superieure in Paris have expressed a keen interest to use the HIA amplifiers to study the DC and RF characteristics of single-walled carbon nanotubes. The Band 3 team is in the process of formulating the technical requirements of a new generation of cryogenic amplifiers to operate up to the 30-40 GHz range.
For more information on the ALMA Band 3 Receiver Project contact Keith Yeung (Project Manager, keith.yeung@nrc-cnrc.gc.ca), Stephane Claude (Project Engineer, stephane.claude@nrc-cnrc.gc.ca), or Doug Johnstone (Project Scientist, doug.johnstone@nrc-cnrc.gc.ca).

3.2  Software

Software work for the ALMA Offline system and the ALMA Common Software system is continuing in Calgary and at DRAO. Raymond Rusk continues to work on the porting of the AIPS++ application libraries for the reduction and analysis of radio astronomy data into the new CASA framework. In the new framework, the libraries are accessible through a direct Python binding as well as an ALMA Common Software (ACS) Corba binding. He has completed porting the Calibrater tool for synthesis calibration and is in the final testing stage of porting the Measures tool, which is used for handling units, quantities, and reference frames including coordinate and time conversions. He is also working on the Coordsys tool, which is used for creation and manipulation of coordinate systems, and the Image tool, which is used for accessing and analyzing images. Work on these modules should be complete by mid-September.
Since the previous report, Dr. Gary Li, who has worked on the ALMA offline software for the past two years at the University of Calgary, returned to his roots in the geophysics community. Gary was a valued member of the Off-line team and we wish him well in his new position. Shannon Jaeger, Gary Li's replacement, joined the offline team just in time to attend the ALMA Offline Developer's meeting which was held in Calgary from June 1-6, 2006. Shannon will be spending a couple of weeks in Socorro during July to come up to speed on CASA development. She is currently working on the migration of the Functionals tool to the new framework.
The ALMA Offline Developer's meeting was held at the CASCA/AAS conference hotel June 1-6, 2006. This meeting allowed the offline developers to mix and become acquainted with some members of the Canadian astronomical community. It also provided an excellent environment in which the team could rapidly debate some key implementation details necessary for the first release of CASA planned for later this year. A follow-up meeting to be held in conjunction with the Tuscon ADASS meeting is planned for this fall.
David Fugate, an ALMA Common Software worker located at the University of Calgary, has accepted a position at Microsoft to begin in early August. David's expertise from four years of developing ACS software, both with NRAO in Socorro and at the University of Calgary, will be difficult to replace. We wish him the best of luck as he returns to the United States with his new Canadian bride.
Chris Wilson was heavily involved in the second user test of the ALMA Pipeline which began in early March and ran for a month. Brenda Matthews from HIA and John Hibbard and Ed Fomalont from NRAO were the other astronomers involved in this test. The test focused on flagging and calibration of single field interferometric data. Because no real or simulated ALMA data are available yet, the test used data from the VLA and the Plateau de Bure interferometer. The test was quite successful, with the testers who had participated in the previous year's test noting that there had been a lot of progress in the pipeline algorithms. The next user test is planned for late fall and will include full end-to-end processing of the data for the science target for the first time.
HIA hosted a successful ALMA Archive team meeting in Tofino from May 12-13, 2006, with 6 of the 8 members in attendance. Technical issues and the distribution, coordination, and scheduling of tasks were the focus of the meeting. Norman Hill continues to attend the weekly ALMA Archive team teleconferences. Delays in hiring continue to prevent the CADC from making its full contribution to the ALMA Archive development; once the position is filled, work will begin on the design and implementation of the Request Handling component of the Archive system.
Chris Wilson wilson@physics.mcmaster.ca
Canadian ALMA Project Scientist
(with input from Séverin Gaudet, Doug Johnstone, and Raymond Rusk)



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