From awootten at nrao.edu  Mon Dec  2 10:37:42 2002
From: awootten at nrao.edu (Al Wootten)
Date: Mon, 2 Dec 2002 10:37:42 -0500
Subject: [asac]ASAC Agenda 4 Dec 2002
Message-ID: <15851.32326.526724.624447@polaris.cv.nrao.edu>

Folks,

Chris has provided some items for the agenda of the next telecon.
Please comment, suggest speakers, etc.
http://www.cv.nrao.edu/~awootten/mmaimcal/asac/asacdec02agenda.html

Telecon contact numbers will be distributed later today, and listed on
this web agenda.

Clear skies,
Al
+--------------------------------------------------------+
| Alwyn  Wootten   (http://www.cv.nrao.edu/~awootten/)	 |
| Project Scientist, Atacama Large Millimeter Array/US   |
| Astronomer, National Radio Astronomy Observatory       |        
| 520 Edgemont Road, Charlottesville, VA 22903-2475, USA |
| (434)-296-0329 voice             Help us build The ALMA|        
| (434)-296-0278 FAX               {>    {>    {>    {>  |
+----------------------------------^-----^-----^-----^---+


From awootten at nrao.edu  Tue Dec  3 11:27:13 2002
From: awootten at nrao.edu (Al Wootten)
Date: Tue, 3 Dec 2002 11:27:13 -0500
Subject: [asac]ASAC Agenda 4 Dec 2002
Message-ID: <15852.56161.131412.376208@polaris.cv.nrao.edu>

Folks,

The agenda is located at:
http://www.cv.nrao.edu/~awootten/mmaimcal/asac/asacdec02agenda.html
We are currently filling in speaker names.

Contact information is in the agenda, but here it is for your
convenience:

 MEETING INFORMATION :
 ==============================
 RESERVATION CONFIRMATION #: 9877086

 AUDIO ACCESS INFORMATION:
 ==========================
 PRODUCT TYPE:  UNATTENDED
 CALL TYPE: MEET ME

 # OF LINES:              Total=25 Dialout=0 Meet Me=13 Meet Me Toll=12
 Entry Method: Tone In
 CALL DATE:         DEC-04-2002  (Wednesday)
 CALL TIME:         10:30 AM EASTERN TIME 1530 Universal Time
 DURATION:              3 hr  (We all hope not!)
 USA Toll Free Number: 877-917-5782
 USA Toll Number: +1-630-395-0482
  PASSCODE: 10120
  LEADER:            DR AL WOOTTEN


  FEATURES:
  =======================
  Tones

Clear skies,
Al









From wilson at physics.mcmaster.ca  Tue Dec  3 22:18:55 2002
From: wilson at physics.mcmaster.ca (Christine Wilson)
Date: Tue, 3 Dec 2002 22:18:55 -0500 (EST)
Subject: [asac]AIPS++ Audit with summary
Message-ID: <Pine.SOL.3.91.1021203221745.12733D-100000@eccles>

Hi, everyone,

See message from Steve Myers about the AIPS++ AUdit document with summary 
attached.

Chris

---------- Forwarded message ----------
Date: Tue, 3 Dec 2002 19:32:43 -0700 (MST)
From: Steven T. Myers <smyers at aoc.nrao.edu>
Subject: Audit summary


There is a draft version of the ALMA AIPS++ Audit with a Summary section
at the end.  You can find it at 
http://www.aoc.nrao.edu/~smyers/alma/audit/ALMAoffline_audit.pdf



From wilson at physics.mcmaster.ca  Wed Dec  4 09:20:50 2002
From: wilson at physics.mcmaster.ca (Christine Wilson)
Date: Wed, 4 Dec 2002 09:20:50 -0500 (EST)
Subject: [asac]some science examples for calibration
Message-ID: <Pine.SOL.3.91.1021204091346.12901A-100000@eccles>

Hi, everyone,

Here is a summary of the science examples for calibration that John and I 
have received so far. Thank you to Ken Tatematsu and Brenda Matthews 
(Berkeley) for their contributions.

Chris

-------------------------

Flux/bandpass calibration; beam pattern:

In order to investigate how molecular clouds form in galaxies,
one will propose to map extragalactic, early-phase molecular
clouds in the nearby galaxy, e.g., M51, in the 492 GHz CI 3P1-3P0 line,
For the single-dish sampling,
one should know contribution of the CI  emission
in the error pattern (about 30 % of the total).
In addition to the accurate knowledge of the beam pattern,
we may need to know the CI distribution
(with velocity infomation) outside of the area
of interest, to obtain well-calibrated line-strength.

Polarization

"normal"
-measure polarization morphology in an isolated protostar or 
	circumstellar disk; similar requirements apply to measuring	
	the polarization of Sgr A* in the mm/submm 
- polarization percentage 0.5-5%
- S/N 5-10 (to get 11-6 degrees uncertainty on position angle)
- continuum mode
- frequency ~300 GHz (whatever combination of dust emissivity and 
receiver sensitivity gives the best overall sensitivity is what would be 
prefered)

"demanding"
-same experiment as above but in a region with extended and complex 
	emission so that Single Dish polarization data must be included 
	with the same overall requirements

"demanding"
-use the dispersion in the polarization angle to measure the magnetic 
	field strength in the plane of the sky versus radius in an 
	extended star forming region like a massive protostar
- polarization percentage: down to 0.1% (to get low polarization in the 
	extended envelope)
- S/N = 10 (for 6 degree uncertainty in polarization angle)
- continuum mode as in previous examples

"demanding"
- measure polarization pattern at several frequency to use the spectrum 
	of polarizations to constrain dust grain properties; could also
	be interesting to measure Sgr A* polarization at several frequencies
- polarization percentage 0.5-5% (but maybe lower in some cases)
- S/N 5-10 
- continuum mode
- range of frequencies i.e. 100 GHz, 300 GHz, 800 GHz with matched
  angular resolution

"demanding" ?
- use the linearly polarized emission from CO lines to probe magnetic
field geometries in protostellar outflows.  (other lines, i.e., HCN, are
also possible).  At high resolution (10s of AU in nearby regions), these
data could test mechanisms for generation of outflows (i.e. X-winds vs.
disks, if the theorists will make testable predictions); in more distant
sources, the magnetic field geoemetries of the outflows can be determined 
using data coupled with the Goldreich-Kylafis effect to interpret the 
polarization angles. Different configurations are predicted for dipolar 
and quadrupolar outflows.
- polarization percentage expected to decrease with J transitions
- CO 3-2 typically 1-2% in single dish observations
- need S/N 5-10 to nail down position angle with uncertainty of 10 degrees
or better
- CO 2-1 also doable, and possibly 4-3 if lower transitions are strong







From wilson at physics.mcmaster.ca  Wed Dec  4 13:56:19 2002
From: wilson at physics.mcmaster.ca (Christine Wilson)
Date: Wed, 4 Dec 2002 13:56:19 -0500 (EST)
Subject: [asac]draft statement on correlator enhancement
In-Reply-To: <Pine.SOL.3.91.1021204091346.12901A-100000@eccles>
Message-ID: <Pine.SOL.3.91.1021204134955.12901T-100000@eccles>

Hi, everyone,

Here's a draft statement on the correlator enhancement proposed in memo 
441. Please send me any comments/corrections by the end of the day tomorrow.

Thanks,
Chris

The ASAC has read with interest the proposal in ALMA Memo 441 by Escoffier
and Webber to enhance the performance of the baseline ALMA correlator. The
relatively small number of spectral channels available in the wide
bandwidth modes is a major scientific limitation of the baseline
correlator that would be remedied if this enhancement could be carried
out. Therefore, the ASAC encourages the ALMA project to see if this
enhancement to the correlator can be implemented within the baseline ALMA
project. 



From Pierre.Cox at ias.u-psud.fr  Wed Dec  4 14:29:20 2002
From: Pierre.Cox at ias.u-psud.fr (Pierre.Cox at ias.u-psud.fr)
Date: Wed, 4 Dec 2002 20:29:20 +0100 (MET)
Subject: [asac]draft statement on correlator enhancement
In-Reply-To: <Pine.SOL.3.91.1021204134955.12901T-100000@eccles>
Message-ID: <Pine.GSO.4.10.10212042021320.4805-100000@neptune.ias.u-psud.fr>

Hi Chris,

Thanks for writing up a draft statement on the correlator
enhancement. The recommendation reads well. I was wondering if
we should not specifically state what the enhancement is about,
i.e. after the first sentence. Something along the lines of:
' The proposed enhancement will increase the number of channels in the
wide band mode from 256 to 8192 points in each 2 GHz from the 16 GHz
available, and therefore allow for better resolution'.

Regards,

Pierre



From bachiller at oan.es  Thu Dec  5 03:27:38 2002
From: bachiller at oan.es (Rafael Bachiller)
Date: Thu, 05 Dec 2002 09:27:38 +0100
Subject: [asac]draft statement on correlator enhancement 
In-Reply-To: Your message of "Wed, 04 Dec 2002 13:56:19 EST."
             <Pine.SOL.3.91.1021204134955.12901T-100000@eccles> 
References: <Pine.SOL.3.91.1021204134955.12901T-100000@eccles> 
Message-ID: <E18JrMA-0004ON-00@conga.oan.es>


Hi Chris,

Your text reads indeed very well, but I agree with Pierre that
we should mention that the SAC is interested about the maximum possible
enhancement, i.e.: a factor 32 in the number of channels for the wide band
mode (going from 256 to 8192).

Cheers,     Rafael



From wilson at physics.mcmaster.ca  Thu Dec  5 09:16:01 2002
From: wilson at physics.mcmaster.ca (Christine Wilson)
Date: Thu, 5 Dec 2002 09:16:01 -0500 (EST)
Subject: [asac]draft statement on correlator enhancement
In-Reply-To: <Pine.SOL.4.31.0212051012030.19401-100000@circe>
Message-ID: <Pine.SOL.3.91.1021205091454.13581B-100000@eccles>

Hi, Malcolm,

We clearly don't want to delay the project. But my feeling is that we, as 
a science committee, can safely leave the managers to worry about that 
end of things.

Chris

On Thu, 5 Dec 2002, C.M. Walmsley wrote:

>  Hi Chris,
>      The statement reads fine but I wonder whether one should not
> add a word of caution to the effect that this should not delay or
> substantially add to the cost of the baseline project.
>  That is sort of implicit in the last sentence but it could be made
> more explicit,
>               Best, Malcolm
> 
> 
> 


From wilson at physics.mcmaster.ca  Thu Dec  5 10:03:31 2002
From: wilson at physics.mcmaster.ca (Christine Wilson)
Date: Thu, 5 Dec 2002 10:03:31 -0500 (EST)
Subject: [asac]revised statement on correlator enhancement
Message-ID: <Pine.SOL.3.91.1021205100021.13581E-100000@eccles>

Hi, everyone,

Here is a revised statement on the correlator enhancements. Unless I hear 
other suggestions for changes, I will send it off at the end of today.

Chris

The ASAC has read with interest the proposal in ALMA Memo 441 by Escoffier
and Webber to enhance the performance of the baseline ALMA correlator. 
The proposed enhancement will increase the number of channels in the wide
band mode from 256 to 8192 points in each 2 GHz of the 16 GHz available,
and therefore allow for better resolution. The relatively small number of
spectral channels currently available in the wide bandwidth modes is a major
scientific limitation of the baseline correlator that would be remedied if
this enhancement could be carried out. Therefore, the ASAC encourages the
ALMA project to see if this enhancement to the correlator can be
implemented within the baseline ALMA project. 





From walmsley at arcetri.astro.it  Thu Dec  5 04:21:23 2002
From: walmsley at arcetri.astro.it (C.M. Walmsley)
Date: Thu, 5 Dec 2002 10:21:23 +0100 (MET)
Subject: [asac]draft statement on correlator enhancement
In-Reply-To: <Pine.SOL.3.91.1021204134955.12901T-100000@eccles>
Message-ID: <Pine.SOL.4.31.0212051012030.19401-100000@circe>

 Hi Chris,
     The statement reads fine but I wonder whether one should not
add a word of caution to the effect that this should not delay or
substantially add to the cost of the baseline project.
 That is sort of implicit in the last sentence but it could be made
more explicit,
              Best, Malcolm




From soliver at nrao.edu  Thu Dec  5 16:34:31 2002
From: soliver at nrao.edu (Stacy Oliver)
Date: Thu, 5 Dec 2002 14:34:31 -0700
Subject: [asac][almanews] ALMA Memos 437 Released
Message-ID: <BMEMJIODJJCHEPGJLCCFEEKCCGAA.soliver@nrao.edu>

ALMA MEMO #437

Miniature, Modular Heat Sinks for ALMA Cryostats

D. Koller, J. Effland, A. R. Kerr, K. Crady and F. Johnson (NRAO)

2002/12/02

Keywords:  miniature heat sink, cryogenic electronics, thermal
measurements

Proposed receiver cartridges for ALMA may utilize up to 96 wires for SIS
mixer bias, IF amplifier bias, thermometry and other functions [1].  To
reduce heating of the mixer block and minimize the load on the 4 K
refrigerator stage, heat sinks will be required on the 80 K, 12 K and 4
K stages.  The present concept for the receiver cartridges requires
disassembly of each thermal stage to effect repairs.  Heat sinks
utilizing connectors simplify disassembly, thus improving the mean time
to repair.  The large number of wires and connections will require a
simple, reliable heat sink capable of being mass-produced for the
expected 64 receiver cartridges.

The main body of this report describes two different heat sink designs
utilizing Nanonics "Dualobe" connectors configured in a modular
arrangement for simple installation in receiver cryostats.  In Appendix
B, a simpler but less effective heat sink is described.  The measured
thermal performance of all the heat sinks is presented.

View a pdf version of ALMA Memo #437.
http://alma.aoc.nrao.edu/memos/html-memos/alma437/memo437.pdf

Download a postscript version of ALMA Memo #437.
http://alma.aoc.nrao.edu/memos/html-memos/alma437/memo437.ps
_______________________________________________
Almanews mailing list
Almanews at listmgr.cv.nrao.edu
http://listmgr.cv.nrao.edu/mailman/listinfo/almanews


From soliver at nrao.edu  Fri Dec  6 17:28:26 2002
From: soliver at nrao.edu (Stacy Oliver)
Date: Fri, 6 Dec 2002 15:28:26 -0700
Subject: [asac][almanews] ALMA Memos 442 Released
Message-ID: <BMEMJIODJJCHEPGJLCCFEEKNCGAA.soliver@nrao.edu>

ALMA MEMO #442

The Intensity Calibration Framework for HIFI

Volker Ossenkopf, (SRON Groningen)

2002/12/05

Keywords: Calibration


Existing schemes for the calibration of radio-astronomical observations are insufficient for the application in forthcoming space
missions with heterodyne systems like HIFI. Many of the approximations used are not valid for systems with large IF frequencies and
they are too rough for the desired calibration accuracy of a few percent. Moreover, they do not exploit the full capabilities of
instruments with two thermal load for the bandpass calibration. We propose a new calibration scheme for the planning and reduction
of HIFI observations, taking advantage of the lack of an atmosphere and correcting for the effects of standing waves in the combined
observation of lines and continuum with HIFI.

The new calibration scheme uses a separate OFF measurement to determine the properties of standing waves between the subreflector
and the receiver. Two different effects are corrected. Standing wave ripples are removed from the continuum level providing the
spectral baseline of the observations and the modulation of the line strengths by standing waves is corrected in the absolute line
calibration. However, at high frequencies the standing wave correction imposes severe constraints on the integration time for the
OFF measurement. A reasonable use of the standing-wave calibration is thus only possible if the standing wave pattern is stable over
long time scales.

We have also provided an accurate estimate of the error budget of the calibration allowing to put clear limits on the accuracy of
the different instrumental parameters required to achieve a given intensity calibration accuracy.

View a pdf version of ALMA Memo #442.
http://alma.aoc.nrao.edu/memos/html-memos/alma442/memo442.pdf

Download a postscript version of ALMA Memo #442.
http://alma.aoc.nrao.edu/memos/html-memos/alma442/memo442.ps

_______________________________________________
Almanews mailing list
Almanews at listmgr.cv.nrao.edu
http://listmgr.cv.nrao.edu/mailman/listinfo/almanews


From kawabe at nro.nao.ac.jp  Thu Dec 26 03:36:11 2002
From: kawabe at nro.nao.ac.jp (Ryohei Kawabe)
Date: Thu, 26 Dec 2002 17:36:11 +0900
Subject: [asac]Achievement of Sub-mm observations with ASTE 10m Antenna
Message-ID: <00a301c2acb9$d9c133c0$b3dc2885@KAWABEVAIO>

Dear Madam and Sir,

On behalf of ASTE Team, we announce the successful observations of [CI] 492
GHz line with ASTE (Atacama Sub-mm Telescope Experiment) 10m antenna on
December 9th, 2002.
 ASTE is a project to install and operate a 10-meter submillimeter telescope
at Pampa la Bola (4800 m in elevation) of the Atacama desert in the northern
Chile. The project is driven by the National Astronomical Observatory of
Japan (NAOJ) in collaboration with Universidad de Chile, and also with
Japanese astronomers from universities including the University of Tokyo,
Nagoya University, and Osaka Prefecture University. There are two main
purposes in the project. First we are aiming at the on-site testing of high
precision submillimeter antenna and high sensitivity receivers for
development toward the ALMA project. The ASTE project offers a very unique
opportunity of astronomical observations of the southern sky in the
wavelengths as well. In the latter respect, the ASTE 10 m antenna will be
the only large (i.e., 10-m class) submillimeter telescope in the southern
hemisphere that works in these wavelengths shorter than 0.7 mm (frequencies
higher than 400 GHz).



The ASTE 10m antenna was transported to Pampa la Bola in March 2002 after
assembling at San Pedro de Atacama site. From April, we started several
measurements to evaluate antenna performances. As a result, antenna blind
pointing is as accurate as 1.5? (rms), and surface accuracy is measured to
be 29 micron (rms) at this moment. First we installed ASTE evaluation
receiver composed of three receiver bands, 100 GHz, 230 GHz, and 345 GHz,
together with four sets of XF-type digital auto-correlators, one of them
covers 512 MHz with 1024 frequency channels. A 3-band bolometer system at
350 GHz, 650 GHz, and 850 GHz was also installed. Recently, we installed an
ALMA- type (i.e., cartridge type) receiver which consists of three
cartridges, that is, band-3 (100GHz), band-8 (490 GHz), and band-10 (810
GHz). The engineering evaluation of the receiver was successfully performed.
The test observations with band-8 receiver was made on Dec. 9th, 2002, and
we succeeded in detecting [CI] 492 GHz line from Orion-KL (see Fig. 4 in the
attached PDF file). The observational condition was good even in the summer
!; opacity at 492 GHz was less than one during the night. The sub-mm
observations with ALMA will be very promising. We would greatly appreciate
your kind understanding and cooperation toward this ASTE project.

 Best Wishes,

Satoshi Yamamoto (Univ. of Tokyo) and,
 Ryohei Kawabe (NAOJ)
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