[mmaimcal] Re: Draft summary of ALMA low frequency issues

[Al Wootten]

Thanks, Steve.

The ASAC decided today that it will examine this problem in detail in
Leiden on 10-11 March at its face-to-face meeting.  In the meantime, 
this band is not to be designed out of the system (I told John Payne
that in the DH meeting).  John replied that if he knew it were to definitely
be in the system he would put it in the main dewar.  On the other hand,
Bob Brown told me that since it was not in the main dewar, it was no longer
part of the baseline plan!!  I would add to your list of research areas
a few items made in discussions on mmaimcal a few weeks ago, or during my
talk at the MAC swansong meeting in October:

Although the point source sensitivity may be comparable to the upgraded VLA,
ALMA/Q provides access to the southern sky (Frazer pointed out that it
wins below dec=0 owng to the declining efficiency of VLA antennas).
Furthermore, ALMA/Q has surface brightness sensitivity an order of magnitued
better than the VLA.

Frazer pointed out that Q band would be important to examine the fate of
higher energy particles in extended sources, such as SNRs and radiogalazies.

ALMA/Q makes good use of marginal atmospheric conditions.  Frazer and Mark
estimated this at 10% but we should improve these numbers. I'm sure we
can concoct a graph to make this point effectively.

ALMA/Q is excellent for imaging of low excitation widespread line emission
(e.g. HC3N 5->4, SiO 1->0, SO and other molecules).

It is critical to determine flare locations for followup at higher frequencies
owing to its quite good field of view.

Pierre Cox reported that the PLANCK folks, along with Francois Viallefond,
were making simulated ALMA observations of S-Z emission.  It will be  a
few weeks, he reports. before this is available.

Clear skies,
Al