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Contact Information

  • 2008-9-17 14:30 UT
  • Note: C. Wilson points out line noise may be muted by pressing *6 which works thru the call center.
  • Duration: 1 hr
  • USA Toll Free Number: 877-874-1919
  • Toll Number: +1-203-320-9891
  • Passcode: 185064
  • Leader: Al Wootten
  • Attendees:


  1. Old Business The enhanced Agenda from last meeting is available. Science IPT notes from last month's telecon are attached to the bottom of the agenda.

Moon imaged with AEC (l) and Vx (r) antennas Calibrated raster maps of the moon using data taken on 6 August with the AEC (left) and VA (right) antennas.

See other images and animations. See other images and transporters.

  1. New Business--Project news/updates (Hills, Peck)
  • New Project Director, Manager, Deputy Manager.
  • ALMA Status Report R. Hills. See attachment below: for a recent set of slides. (These are more or less what was given at the regional science meetings last week. I think you will have seen most of them before but there are some new pictures.)
    • Site: Installation of foundations continues. 22 high site pads have received structural concrete. There are still several concerns here: the stiffness they provide; the design and positioning of the steel inserts that the antennas sit on; the practicality of the vaults where the power and fibers are connected. A new concern is that the plans had been revised (without review) to place the antennas of the central cluster on a series of terraces in order to accommodate a transporter spec of exactly zero degrees slope. This would have produced vertical offsets of as much as 1.5m between neighboring antennas, significantly affecting imaging and shadowing. (The specifications say that the central cluster should have all the antennas in a plane to within +/- 0.4m.) A group is meeting to find a new solution. We have also had to remind site IPT that we need to use pads in the central cluster for Early Science so their construction can not be put off until late in the project as they had planned.
    • Antennas: Testing of in MELCO #2 anntenna is complete and provisional acceptance (with the issue of the thermal behaviour still to be resolved) will occur as soon as the documentation and review is complete - probably early November. The installation of the ALMA electronics racks in this antenna has been carried out and the Front End is going in about now. A lot of holography data has been taken on MELCO #1 to investigate the thermal problem. Vertex #1 and #2 are doing pointing tests and are in early stages of a staged acceptance review. AEM #1 has completed its drive tests. A PPDR for the ACA 7m antennas was held last week. To the surprise of most of the review panel the design is all steel with air circulation to provide thermal uniformity. According to the detailed thermal modelling, back by an experimental rig of one section of the antenna, this should still reach the 20 micron surface accuracy goal under the conditions when submm observing is possible, including the mornings.
    • Front Ends: Delivery - the second "engineering model" front-end is under test in Taiwan and should be shipped to Chile by Nov 2008.
    • Correlator: The final stage of assembly of the first quadrant started in the AOS TB.
    • Software: Slow progress at ATF; leads meeting. Overall external review planned for 17-23 Nov.
    • Systems: Revisit to the Systems Requirements planned - we need to discuss this.
    • Schedule: The schedule review is in full swing. The outcome of the detailed re-assessments will be reviewed in early October and a the new "firm" overall schedule will be prepared by the beginning of November.
    • ASAC Matters.
      • Face-to-face meeting in Charlottesville after Massive Star Formation Workshop
      • Panel to prepare ALMA Development Proposal has had two telecons

  1. Directories

Science IPT Group Activity Reports

Please include your Group Activity Report here (How to Enter Your Report), or email it to AlWootten

Project Scientists

  1. Science IPT
    • Change Control Board items, other technical concerns (Hills)
      • Band 3 Receiver Noise Temperature Specification This is a request to relax the sensitivity requirements for this band (although the requirement for the outer edges of the band is tightened). I suggested last time that the overall loss in sensitivity is not very large (perhaps 2 or 3 percent) but in fact it is a good deal more than this. Rainer checked the numbers taking into account typical atmospheric conditions and it is more like 6 to 8% in system temperature. We are awaiting more comments from FE_IPT but any comments for a more complete response from Science would be helpful. See Todd Hunter's summary.
      • ACA 7m surface specification change to 25 microns during daytime. Although this has been submitted it is likely that it will now be withdrawn and an effort made to ensure that the 20 micron number is achieved at least into the middle of the morning under typical (good) conditions. (Emerson)
    • Improvements to the extended configurations were discussed in the Grenoble Simulation workshop (Wootten, others)
    • ATF: (Peck)
      • Summary. ATF will operate thru 20 Dec, if at all possible.
      • Present goals: (1) Getting software working (2) Developing procedures needed for AIVC, and (3) Training personnel
      • Presently testing software version 5.1.1 which includes facilities for taking total power data and for using the ACA correlator. Total power modes are working well, and we are doing interferometry using control scripts written by Sci IPT members which will be tested and then turned into ALMA OT modes.
      • Hardware is in a fragile state and maintenance in Sept will be essential if operations are to continue.
      • The current schedule is below. Note that R. Laing will take over scheduling visiting science staff on Sept 1, and Debra will continue to schedule daily shifts at the ATF. During the current period foci of interest include further understanding of the behavior of the Line Length Corrector, identifying causes of latency, writing and exercising new control scripts, and reviewing the MS data more carefully to make sure the current version of the filler at the ATF is converting data properly.
      • Sci IPT at the ATF Checklists, Progress Reports, OSF and ATF.
      • CIPT Wiki Daily ATF reports.
      • AIV wiki OSF/AIV Daily log.
Week Event
Sep 1 - 17
no science scheduled - antenna maintenance

  • OSF
Week Event
Aug 20
Remote support for OPT; R. Lucas now at SCO

  1. Next meeting is on Oct 15th (14:30 UT). Nov 19th for the following month.
  2. Astronomer Outreach: New ESO ALMA Webpages.][NRAO Newsletter]]. NAOJ News. NRAO ALMA Calendar

Richard Hills, Alison Peck, Robert Laing -- Commissioning and Science Verification

  • Commissioning and Science Verification
    • Plan.
    • A request for additional manpower has cleared the Directors Council and should go to the Board on 25th Sept.

Emerson/Laing/Vila-Vilaro -- Instrument Scientists

Jeff Mangum -- Calibration

  • Response to ASAC comments
  • Pointing Design document now drafted. Waiting for release of metrology system details to complete.
  • Calibration Plan: Current version of the calibration plan and associated documents ("examples", "roadmaps", "matrices", etc.) posted. Comments welcome.
  • Calibration Examples: The "meat" of the Calibration Plan. Review of these documents nearly complete, some need updates.
  • Ancillary Calibration Devices:
    • Documents which describe the weather station and temperature profile technical specifications have been developed.
    • Initial purchase of (P,T,RH,Ws,Wdir) measurement devices has been made by Leonardo.
    • Specification of site infrastructural components (enclosure, tower, etc.) have been made and sent to Site IPT.
  • Refractive Bending and Delay Calculations:
    • Analysis complete. See wiki page for details.
    • Recent analysis of Yan refractive bending model suggests that it is limited (using sla_refro as benchmark).
    • Worked with Pat Wallace to implement improvements to sla_refro, including incorporation of Liebe atmospheric model.
    • Recommendation is to use sla_refro for refractive bending (note: currently used in M&C software in use at ATF).
  • ALMA Calibration Device (ACD): Several reviews (involving acronyms that I won't repeat) of ALMA Calibration Device (ACD) over past month point to both good and bad:
    • Good: Robotic arm tests suggest that positioning between bands will be as fast as 5-6 seconds, rather than the anticipated 9 seconds.
    • Bad: Frontend IPT unilaterally changed specification of solar filter to exclude use at Bands 1 and 2. Change not approved, and justification for change flawed.

Robert Lucas -- SSR

  • SSR meeting this month. (2008-09-10).
  • Transformation into new body to begin by end of year.

Testi, Leurini-- Design Reference Science Plan

  • working on version 2.1, adding some projects, cleaning up.
  • summary spread sheet almost completed.
  • Some items to be added - more polarization cases, pulsars, is there anything on fine-structure in hot haloes using S-Z?

Wootten -- Site Characterization

  • Weather station deployment: ICD Site to Weather instruments.
    • Shelter. AW responded to Eduardo's comment, to which AW had already responded in the revised document. Site did not provide for the shelter. AW proposed reusing the container, which was originally a proposal from Eduardo's predecessor and seems a minimal money investment to me.
    • Fiber. Eduardo protested that the fiber was procured. Fabio noted that the report of the June site infrastructure review was out and that there were mistakes noted in addition to nonoptimal solutions to the fiber layout. In his opinion, the plan would need to be readdressed in any event and the inclusion of additional fibers for the weather stations was a small problem. Eduardo noted that there would be some details in the connection at the antenna pads.
    • Power. The power distribution is three phase 440 V. Donoso noted that two phases provide the necessary voltages to run the weather stations. Making sure that this is done at the site is a matter of field engineering, a locally solved problem. What subset of the ten weather station locations will receive the seven stations we purchased? Last chance for input.
  • OSF Weather Station link.
  • APEX Weather Station link.

Remijan, Markwick-Kemper -- ALMA Working Group on Spectral Line Frequencies

Science Corner:

Simulations of the Sunyaev-Zeldovich Effect from Quasars Suchetana Chatterjee (Pitt), Tiziana Di Matteo (CMU), Arthur Kosowsky (Pitt), Inti Pelupessy (CMU)

Abstract:Quasar feedback has most likely a substantial but only partially understood impact on the formation of structure in the universe. A potential direct probe of this feedback mechanism is the Sunyaev-Zeldovich effect: energy emitted from quasar heats the surrounding intergalactic medium and induce a distortion in the microwave background radiation passing through the region. Here we examine the formation of such hot quasar bubbles using a cosmological hydrodynamic simulation which includes a self-consistent treatment of black hole growth and associated feedback, along with radiative gas cooling and star formation. From this simulation, we construct microwave maps of the resulting Sunyaev-Zeldovich effect around black holes with a range of masses and redshifts. The size of the temperature distortion scales approximately with black hole mass and accretion rate, with a typical amplitude up to a few micro-Kelvin on angular scales around 10 arcseconds. We discuss prospects for the direct detection of this signal with current and future single-dish and interferometric observations, including ALMA and CCAT. These measurements will be challenging, but will allow us to characterize the evolution and growth of supermassive black holes and the role of their energy feedback on galaxy formation.

Constraints from deuterium on the formation of icy bodies in the Jovian system and beyond Jonathan Horner, Olivier Mousis, Yann Alibert, Jonathan I. Lunine, Michel Blanc

Abstract: We consider the role of deuterium as a potential marker of location and ambient conditions during the formation of small bodies in our Solar system. We concentrate in particular on the formation of the regular icy satellites of Jupiter and the other giant planets, but include a discussion of the implications for the Trojan asteroids and the irregular satellites. We examine in detail the formation of regular planetary satellites within the paradigm of a circum-Jovian subnebula. Particular attention is paid to the two extreme potential subnebulae - "hot" and "cold". In particular, we show that, for the case of the "hot" subnebula model, the D:H ratio in water ice measured from the regular satellites would be expected to be near-Solar. In contrast, satellites which formed in a "cold" subnebula would be expected to display a D:H ratio that is distinctly over-Solar. We then compare the results obtained with the enrichment regimes which could be expected for other families of icy small bodies in the outer Solar system - the Trojan asteroids and the irregular satellites. In doing so, we demonstrate how measurements by Laplace, the James Webb Space Telescope, HERSCHEL and ALMA will play an important role in determining the true formation locations and mechanisms of these objects.


Events of Interest

(see also Al's ALMA Biweekly Calendar)

Day Date Time Event location details
Sep 17
Sci IPT telecon
Sep 18-19
Band 6 Manufacturing Readiness Rvw
Sep 25-27
NAASC Workshop
Sep 25
ALMA Board
Sep 28-29
ASAC face-to-face
Oct 15
Sci IPT telecon
Nov 17-19
Software Review
Nov 19
Sci IPT telecon
Dec 9-11
ALMA Annual External Incremental Review

Upcoming Meetings

ALMA Simulation Workshop Sept 8-10 Grenoble. Presentations online.

Transformational Science with ALMA: The Birth and Feedback of Massive Stars, Within and Beyond the Galaxy Sep 25-27, Charlottesville.

See ALMA related meetings.

-- AlWootten - 15 Sep 2008 * ALMA_Status_ASAC_Aug08.pdf: Status Report
Topic revision: r7 - 2010-08-02, ToddHunter
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