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2009-10-21 14:30 UT Note UT time unchanged. Summer time ends in Europe 25 Oct and in US 1 Nov.
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Topics
1 Old Business The enhanced
Agenda from last meeting is available. Science IPT
notes from last month's telecon are not available.
DV01 and PM03 have been placed near each other at the AOS in preparation for interferometry, on stations 96 and 109. On Friday 16 October 2009, Joe
McMullin reported:
- 1330 Antenna arrived at station A109 at the AOS
- 1355 Antenna put down on pad
- 1500 Antenna moved via control cabinet on platform
- The next few days will finalize the connectivity, test the computing hardware monitoring and control and begin observations.
See
other images and animations. See
other images.
- New Business--Project news/updates.(Hills, Peck)
- R. Hills
- ASAC met at ESO, Garching, on 13th and 14th Oct. In addition to the usual reviews of project status, discussion of technical issues with implications for performance, (see edm_links, the committee discussed the planning leading to Early Science including the ARCs and the software, especially the observing tool. The reviews of the Commissioning Plans and of Operational Planning were summarized and there was discussion of aspects of the Proposal Review Process and of the Science Requirements.
- A proposed requirement for software "latency" - the overhead time due to software has been drafted and sent to CIPT. Software Latency Requirements (pdf)
- Testing activities at the OSF have continued but at a lower pace due to the antenna moves to the high site. This provides an opportunity to get reports written up.
- The report from the Commissioning and Science Verification Plan Review took place at the OSF on September 2nd and 3rd, chaired by Bob Wilson with other panel members were Nario Kuno, Peter Schilke and Melvyn Wright, has been received.
- A review of the Science Operations took place in Santiago 29-30 Sept.
- Antennas: Elements of more than 16 antennas from all vendors are at the OSF--necessary for early science (but not sufficient). Next antenna acceptance DV05 shortly. First ACA 7m antenna has embarked upon the high seas from Japan.
- Employment
- JAO positions Commissioning Scientists. Search status: Offers made--Two additional commissioning scientist posts have been filled - Lance Simms and Eric Villard will be joining the team early next year.
- ESO ALMA Fellows position open
- ALMA, NAASC positions, more to be advertised.
- NAOJ
- ALMA Science IPT wiki page
- Astronomer Outreach: JAO ALMA Webpages. JAONews. ESO Newsletter No 16 NRAO eNews ALMA News. NAOJ News. NRAO ALMA Calendar
- Current ALMA System Block Diagram Vers P.
- 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
- Change Requests. A significant change request was discussed last meeting: Band 6 CRE. This relates to the Band 6 performance and in particular requests that the range of IF frequencies over which the performance is assured be limited to 6 to 10GHz instead of the original range of 4.5 to 10GHz. The instantaneous bandwidth was always limited to 4GHz so the main effect is to reduce flexibility in making simultaneous observations of two or more lines. In particular it will no longer be possible to observe 12CO J = 2-1 and 13CO J = 2-1 at the same time. Note that these two lines may be observed simultaneously in the J=3-2 line, but not in J=1-0 owing to the interplay between the line separation and the IF choices ALMA has made. We requested a reconsideration of this in particular to assure performance over 5 to 10 GHz but with a relaxation of the gain slope specification. Al reports that. "Tests were made of mixer-preamp performance using the older version of the bonded interface, with the result that the noise temperature in the 4-6 GHz IF range is improved, but gain slope using the present warm IF amplifiers (which have equalizers optimized for 6-10 GHz performance) is an issue." REH received the following from John Effland:
- Between 5 and 10 GHz IF, for 2 GHz bandwidth, gain slope of 5 dB from 6-10 GHz and 6 dB from 5-6 GHz (as per Richard Hill's recommendation).
- Between 5 and 10 GHz, for 5 GHz bandwidth, gain slope of 7 dB
- Get MTS LO fixed to eliminate noise spike - will assume 20% of mixers fail new 5-10 GHz specs.
- CRE should include changing top level science specs, FE, and Band 6 specs.
- Old (IN1A) Design:
- No time at the present for additional experiments. Wait a few months and review production schedule.
- Write up and submit to Science IPT benefits of using IN1A .
- Configuration change. The location of the northernmost pad has been under discussion, see Maps of North Arm (pdf). Sawada-san has checked on the effect of pad relocation (pdf). This main effect is to make the beam somewhat elliptical with the extension N-S. Does anyone see a strong objection? Otherwise we will go ahead with this.
(
BojanNikolic-- I'm not sure it is fair to consider the fitted
Gaussian main beam in this case. This assumes that the observer is
interested in a wide range of angular scales, but obviously in O28
they are likely to be interested in the finest scales.
Maybe the way to tackle this would be to compare the difference in
the fitted main beams between say O25 and O28-original and the
difference in O25 to O28-new. This would show how if (and how much)
on losses with this change, compared with just discarding some of
the most extended configurations.
Also, since I assume the big area of concern here is the loss of
resolution, it would be good to also plot the beam maps in the
report much enlarged (e.g. 0.03x0.03 arcsecs total map size), so
that one can see the change in the main beam and innermost
sidelobes. )
As a partial response
here (pdf) is the u-v coverage for a snapshot observation of a source at the zenith, with some statistics.
- Temporary weather stations installated on roof of AOS TB. Some adjustments, calibrations will be done on them.
- ATCA survey of calibrators at 20 and 95 GHz to be included in OT list.
Bojan Nikolic/John Richer -- WVRs
- The first (quite short) test of the Water Vapour Radiometer phase correction technique at the OSF was carried out on the night 4th October. The preliminary results look encouraging. Plots are shown in attached document OSFFirstResults.pdf
Lars-Ake Nyman -- eSSR
- ALMA SciOps Implementation Plan Review was held at SCO 2009 September 29-30, 2009.
- DRSP updates have been completed
Science Corner:
arXiv:0910.1609
Title: The Science Case for Building a Band 1 Receiver for ALMA
Authors: D. Johnstone, J. Di Francesco, B. Matthews, N. Bartel, S. Casassus, S. Chitsazzadeh, G. Duchene, A. Hales, M. Houde, P. M. Koch, R. Kothes, S-P. Lai, G. Moriarty-Schieven, D. Scott, H. Shang, S. Takakuwa, J. Wagg, A. Wootten
Calendar
1
Next meeting is on
Nov 18th (14:30 UT). Dec16th for the following month.
Events of Interest
(see also Al's
ALMA Biweekly Calendar)
2009 |
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Oct 21 |
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Sci IPT |
telecon |
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Nov 16 |
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ALMA AAER |
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Nov 18 |
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Sci IPT |
telecon |
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Upcoming Meetings
From circumstellar disks to planetary systems Nov 3-6 Garching
Astrobiology Science Conference 2010 April 26-29, 2010 League City, Texas
Recent Meetings (presentations online)
Science at Q Band Sep 14-15, Manchester
Mass Assembly and Star Formation History of Galaxies Sep 21-24, Charlottesville, Virginia
To the Edge of the Universe: 30 years of IRAM Sep 28-30, Grenoble
Data Needs For ALMA. Oct 5-7 Koln Germany
--
AlWootten - 2009-10-20