[asac] draft of letter to ACC; please respond

[Ewine van Dishoeck]

Dear ASAC members,

Below please find the draft of the ASAC letter to the ACC, as written by Jack
Welch and with comments from Geoff Blake and myself included. Please send
comments to me (ewine at strw.leidenuniv.nl) by WEDNESDAY FEBRUARY 28 3 pm
CET at the latest.

Can the designated liaisons please send their drafts for the full ASAC report
to Jack Welch (welch at astro.berkeley.edu) by the end of this week?

As to the next ASAC telecon: I unfortunately have a conflict on Thursday March
15 which I cannot move. The ASAC telecon will therefore be on Wednesday March
14 at 10:15 am EST. My apologies to those who cannot make it at that date. We
will move back to the regular Monday telecons in April.

Many thanks to everyone for their active participation in the discussions
at the Florence meeting!

With best regards,

Ewine


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To:   ALMA Coordinating Committee

From: ALMA Science Advisory Committee


                                                           February 28, 2001

Dear ACC members,


     In early February 2001, the ASAC learned with dismay of further financial
pressures on the ALMA project which would impose a maximum budget of 663M$. In
its meeting in Berkeley in September 2000, the ASAC including (informally) its
new Japanese members, developed a plan for the enhanced ALMA which would
include a new compact array (the ACA) which would enable new science and
enhance the capability for wide field imaging, a suite of ten receivers which
would enable a rich astronomical program over all of the available
millimeter/submillimeter atmospherics bands, and an enhanced correlator which
would significantly increase the speed and sensitivity of the system.  In
October, we learned of a 10% proposed cut in the budget, and we began planning
how we would discuss accomodation of that reduction during our February 23,24
2001 meeting in Florence.  With the further reduction, the new budget limit of
663M$ amounts to only a modest increase over the original 552M$ budget of the
combined European/American Groups, despite the joining of our Japanese
colleagues in the project.  Further, some of this increase must go to the
additional overhead of the larger  organisation.  Since the observing time is
now divided three ways, the advantage to each of the partners of combining the
LMSA/LSA/MMA projects is considerably diluted.

     As regards the impact on the science program from this further proposed
reduction, little more than the ACA and one receiver band (band 10) beyond the
baseline complement of 4 can be added. The ASAC became convinced of the
importance of the ACA through the simulations presented at the Florence
meeting. At the 10% cut level, a total of 8-10 receivers could be included in
addition to the ACA. With the larger cut, the loss of bands 1, 4, and 8
eliminates substantial and important science.  Band 1 at a wavelength of 1 cm
offers unique capability for studying large scale structures forming in the
denser parts of the early universe and for investigating the inner most parts
of disks forming around young stars.  Band 4 is rich in molecular lines which
are important for astrochemistry and the study of the formation of massive
stars, both locally and as signatures of distant (early) galaxy formation. 
Band 8 contains perhaps the most important continuum emission from newly
forming low mass stars and the emission from ubiquitous atomic carbon in
nearby galaxies, important for galactic structure studies. The loss of the
next generation correlator implies a decrease in observing speed for some of
the highest ranked scientific programs by up to a factor of two.

     ALMA is a unique project, the only major world telescope in the next few
decades for millimeter wavelengths.  This plan for a single telescope stands
in sharp contrast to the situation in ground based optical and infrared
astronomy, where there are many systems including the dual Gemini 8 m
telescopes, the Japanese Subaru telescope, the VLT system of ESO, and, in the
private sector, a number of major instruments such as the dual 10 m Keck
telescopes.  The ALMA project is the major new initiative in astronomy in many
countries. It is an exciting new instrument, full of the promise of answering
many fundamental questions in astrophysics.  It deserves the fullest support.

Sincerely,


         The ALMA Scientific Advisory Committee