ALMA Update

1 Recent news

1.1 Construction Progress

By the end of 2007, seven ALMA telescopes will have been delivered to Chile (about one tenth of the final total). The third VertexRSI antenna pedestal arrived in port in Chile on December 8. The upper 'inverted umbrella' portion which supports the reflector surface is expected to arrive in port by the end of December. It joins three antennas delivered by Mitsubishi Electric Company (Melco) of Japan. The fourth Melco antenna was shipped from Japan on October 30 and also arrived in port last week. Assembly and testing of these telescopes continues at the Operations Support Facility outside San Pedro de Atacama. Holography, optical pointing, fast motion and other antenna tests continue with the first of the 12m Melco antennas.

Figure 1: The first three 12 m Melco antennas from Japan.

Work continues on a sixth antenna pad at the VertexRSI Site Erection Facility and on five pads at the Alcatel/EIE/Mann Site Erection Facility. When complete, the total number of antenna pads at the OSF will be 21.

The Factory Acceptance Review for the ALMA transporters was held on November 29th. The massive machines left the Sheuerle factory and traveled to port at Heilbronn, Germany on 3 and 4 December, where they were put onto a barge. They traveled down the Necker to the Rhine, arriving in Antwerp, Belgium on December 11, where they will be transferred to another ship for travel to Chile.

An important milestone was reached on 2007 Nov 30 at the ALMA Test Facility. Interferometry under control of ALMA software was improved to the point that interferometric determination of the baseline between the two antennas will become possible. Interferometric pointing will also be possible.

In personnel, Richard Hills has relocated to Santiago to take up Project Scientist duties. Brian Hoff (ME), Masato Ishiguro (Scientist) and Lewis Knee (Scientist) have started work in the Assembly Integration and Verification group. There are a number of ALMA jobs advertized at NRAO, ESO, and in Chile,

http://www.nrao.edu/administration/personnel_office/careers.shtml
https://jobs.eso.org/ESOCP370/default.asp?PageNo=DEFAULT
http://www.alma.cl/jobops/

1.2 Committees and Reviews

At its meeting on the 30th and 31st October, the ALMA Board agreed not to extend the appointment of the current Director, Massimo Tarenghi, beyond the 31st March 2008 on completion of five years in the post. The Board thanked Massimo for the many contributions he has made to the project and wished him well for the future. Without his energy and enthusiasm for ALMA, the outstanding achievements of the project to date would have been far more difficult to achieve. The Board will initiate a search for a new Director in the very near future.

Changes have also occurred on the ALMA Board and its committees. V. Heyl, the President of CONICYT, has appointed Neil Nagar of U. de Concepcion to take over the ASAC seat being vacated by Diego Mardones, of U. De Chile. Also, Prof. Monica Rubio (U. de Chile) will assume the seat on the ALMA Board which is being vacated by Prof. Leo Bronfman (U. de Chile).

2 ALMA Meetings

2.1 ALMA Science Advisory Committee (ASAC)

The ALMA Science Advisory Committee (ASAC) met via telephone conference in the fall to consider two charges from the ALMA Board. The first charge was related to correlator modes required for commissioning and early science while the second charge discussed the comprehensive calibration plan and the assembly, integration, and verification of ALMA.

ALMA is an extremely complex telescope with both a large bandwidth and the ability to observe at high spectral resolution. Thus the correlator needs to have great flexibility. Indeed, the ALMA specifications total more than seventy correlator modes, far too many for commissioning together during early science. The ASAC was asked to prioritize the modes to maximize the science impact. ASAC strongly suggested that the most important modes for commissioning are (a) the pseudo-continuum mode, (b) the lowest frequency resolution/largest bandwith mode (great for extra-galactic studies), (c) a high frequency resolution/moderate bandwidth mode (for galactic studies using high frequency receivers) and (d) the highest frequency resolution/small bandwidth mode (needed for detailed velocity resolution and galactic studies with Band 3). A full polarization mode (including cross polarizations) will also be recommended.

The calibration and Assembly, Integration, and Verification testing is much more complex and ASAC only offered a preliminary report in the fall. A full discussion of the issues and how they affect the scientific capabilities of ALMA will be undertaken at the next face to face meeting at the end of January 2008.

In the meantime the ASAC is expected to receive two other charges. The first is to assess the preparation of the ALMA real time, observing, and off-line software for early science. This charge was deferred from the fall. An additional charge relates to the ALMA Future Development Plan. The ASAC will discuss these in Chile at the end of January, after touring both the OSF and the AOS (weather permitting).

2.2 ALMA North American Science Advisory Committee (ANASAC)

The ANASAC has met once by telecon in the last three months. The primary action at this meeting was to settle the science topic for the 2008 ALMA workshop (see next section). We also heard reports on the initial Beta release of the CASA software. Douglas Scott from UBC is the newest Canadian representative on the ANASAC. Chris Wilson is continuing to attend the ANASAC telecons as an ex-officio member.

The Proceedings of the First NAASC ALMA Workshop, "From Z-Machines to ALMA: (Sub)Millimeter Spectroscopy of Galaxies", has been published as Volume number 375 of the Astronomical Society of the Pacific Conference Series. A. Baker, J. Glenn, A. I. Harris, J. Mangum and Min S. Yun edited the volume. The Z-Machine is an ultrawide-bandwidth spectrometer optimized for the study of distant dusty galaxies.

2.3 Upcoming Science Meetings

The Öbserving with ALMA" Workshop at Calgary has been delayed until summer 2009 by the SOC. This delay is due in part to the fact that the CFI grant to the University of Calgary to support ALMA software development, as well as this meeting, has been extended until October 2009. The workshop SOC feel that a delay is prudent for a few reasons. First, it will allow the ALMA software development more time to reach maturity. Second, the meeting will now take place closer to the actual start of Early Science with ALMA (scheduled to begin in the latter half of 2010), Hence, by summer 2009, we will know the telescope's early capabilities much better than we do now. Periodic announcements will be made during the upcoming year with new information regarding new dates etc.

The ANASAC has begun planning for a scientific workshop to be held in the summer or fall of 2008. The topic that has been chosen is the formation and feedback of high-mass stars, which dominate the radiative and mechanical luminosities of the universe's most actively star-forming galaxies. This workshop will seek to examine the key questions at this Galactic/extragalactic interface, and how ALMA (in both its current and possible future forms) will help address them. Both Doug Johnstone and Chris Wilson are members of the SOC.

ESO is organizing a workshop on "Gas and Stars in Galaxies: A Multi-Wavelength 3D Perspective" to be held June 10-13, 2008 in Garching, Germany

http://www.eso.org/gal3D2008

This conference aims to bring together the optical/near-IR and submillimetre/radio communities working on 3-dimensional extragalactic data.

3 ALMA Developments in Canada

As mentioned earlier, Lewis Knee has taken a three-year leave from NRC-HIA to join the ALMA Assembly, Integration and Verification team in Chile. We wish Lewis well in his new role and hope to see him back in Canada frequently. James di Francesco has taken over the role of interim Canadian ALMA Project Manager.

3.1 Band 3 Receiver Development

The Band 3 Receiver Development Team successfully held its Critical Design Review (CDR) at the end of September, finalizing the design of the receivers during the production phase. This major review was the focus of the team throughout the summer and over a thousand pages of documentation were produced. A 12-member international review committee was fully satisfied with the receiver design and the progress of the development program at HIA. The review committee consisted of experts in the area of radio astronomy instrumentation from the U.S.A., France, Japan, the Netherlands, Taiwan and Germany.

During the fall another cartridge (the fifth) has been prepared for shipping to the Front End Integration Centre in Charlottesville. The final three pre-production cartridges should be completed and shipped soon into the New Year, at which time the Band 3 team will begin the production run.

The Band 3 Receiver team has also been given the go ahead for the construction of a second Cartridge Test Setup (CTS) in order to be able to meet the demands of the enhanced delivery schedule of receivers brought about by the addition of the ALMA Compact Array. The team expect it will take about a year to complete construction of the second CTS.

On a side note, some of you may have heard rumours that the ALMA front end has a pointing problem, specifically with respect to the Band 3 receiver. We were all excited to hear in November that the problem was with a loose screw in the beam pattern measuring device and NOT the front end assembly. It looks like everything is now full steam ahead with both the receivers and the front ends.

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

In early December, 2007, the CFI was approached to extend the term of the CFI grant to the University of Calgary that funds the Canadian ALMA software development team. The request was successful and the software development is now funded to October 31, 2009. This extension allows all the original money from the CFI grant to complete the software development tasks that have been assigned to our team.

The off-line software development team (Raymond and Shannon) has worked on the CASA beta 0.5 release. During September, October and early November, Raymond completed his work on the vpmanager (antenna voltage pattern manager) tool. He also ported the imagepol tool to CASA. The imagepol tool is used for the polarimetric analysis of images. All the functionality of both tools has been implemented, tested, and documented in the User Reference Manual (URM). Raymond also resolved a number of bugs related to parsing coordinate systems from FITS image headers.

With the departure of Joe McMullin as group leader, Raymond's tasks have changed somewhat. In November, he began work on the regression testing framework to make it more effective for detecting data reduction errors. For Beta 0.5, he added several regression scripts including one for the end-to-end processing of NGC5921 spectral line data, and comprehensive tests of the image, imagepol and coordsys tools.

Shannon completed a number of tasks for the Beta 0.5 release of CASA. These tasks involved many small but time-consuming assignments, one of which was specifying messaging levels for all of the messages in the Measurement Set and Table plot facilities. Her focus from now until the release of Beta, and potentially longer, will be on moving some of the imaging facilities into the task layer of CASA. This will include task level interfaces for image maths, image fitting, and mstat.

Arne Grimstrup's efforts have been focused on preparations for the release of ACS 7.0 on November 16th. His primary tasks were the updating of the ACS suite of Python modules, reworking a portion of the infrastructure which is used to control ACS containers and services, and a variety of bug fixes. Since ACS shipped, Arne has been working on implementing the dynamically configurable logging controls in the Python subsystem and investigating a timing issue that occurs during startup of ACS. He continues to fix bugs discovered in the ACS system and to support the other subsystem teams.

At HIA, Norman Hill and Dustin Jenkins started the implementation of the ALMA Request Handler in October. The Request Handler will provide both a graphical user interface and a programmatic interface to the Archive system to allow users to access data stored in the archives and/or to initiate processing to generate data for retrieval. The implementation is proceeding close to the plan. The initial release of the Request Handler will be ready in late December 2007 or early January 2008, and will support user file downloads and synchronous request processing. Development of the second release of the Request Handler will proceed immediately after the initial release. The second release will add the functionality necessary to process data before it is delivered to users.

Sandra Etoka and Stewart Williams (U. Manchester) and Andreas Wicenec (ESO) have integrated the Request Handler prototype, delivered by the CADC in August 2007, into an overall ALMA Science Archive (ASA) mock-up. A user test is currently underway and will continue until January 7 2008, in which a small group of users will evaluate the ASA Mock-up and provide feedback on how future users will interact with the ASA.

The ALMA Pipeline team has just begun its fifth user test, one which will test automatic processing of the single dish data that is expected from the 12 m antennas in the ACA. Chris Wilson has been helping the development team to prepare for the test and will be the North American tester. She will also write the final report summarizing the responses of the three testers, which should be finished by the end of January, 2008.

Chris Wilson wilson@physics.mcmaster.ca

Canadian ALMA Project Scientist

(with input from Russ Taylor, Severin Gaudet, Doug Johnstone, and James di Francesco and Rene Plume, as well as material from Al Wootten)

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On 17 Dec 2007, 15:22.