[mmaimcal] MMA Deep Field -- the CO Pie almost done...

[Al Wootten]

Jack's program produces an image; I added some output statements
in order to produce a list of the galaxies in that image and their
characteristics--position, inclination, size, z and flux density.

Using the luminosity distance, and these parameters I derived a dust mass
for the emitting 'galaxy' using the recipe in Downes et al. 1992 (ApJ398 L25).
This checks with the F10214 parameters.  It appears that a good estimator of
the total H2 mass is MH2 ~ 500 - 700 (Downes, Solomon and Radford 1995 (ApJ 453
L65) for F10214 at least.  The dynamical mass of stars plus gas is perhaps
50% larger.  Boldly assuming that these parameters apply to all galaxies,
we have the numbers which we need for calculating detectability of various
lines.

For CO I calculated L'(CO) using the formulation in Solomon, Downes and
Radford (1992).  This directly gives the CO flux at some transition
simply by multiplying by the intrinsic brightness temperature ratio of the
lines; I'll take Simon's gross assumption that all lines of interest have
the same brightness temperature for now but I may employ Harvey's
calculations to improve this estimate.

For 64 x 12m antennas at 850 GHz I estimate that one hour one sigma in
250 km/s will be 15 mJy km/s so that 5 sigma will be 75 mJy km/s.  I can
then confront this sensitivity with the galaxies in the image.

It appears to me that a sizable fraction (~75%) of the galaxies detectable in
our paradigm image would be detectable in CO also.  About 16% of the galaxies
might have lines which are detectable and actually fall within the passband
of the image formed by a 64 x 12m array.  I am working on the corrections for
surface brightness (1"=5kpc at 12 Gpc (z=2.3) so this may not be a large
correction) and inclination (assuming randon orientations).

Jack used a 20 kpc disk for the galaxies.  Looking over the literature
it seems to me that 5kpc or smaller might be more appropriate for the
CO-bright parts of galaxies. Simon or Min what do you think?  We have a 1.1"
beam so in this case the corrections will be minimal.  I used the estimate
of the dynamical mass of a galaxy as guesstimated above to arrive at its
intrinsic linewidth; I know the inclination so this will allow me to
estimate linewidth and the actual detectability of a galaxy.

Sooo...Jack's program throws dice differently every time so I generated a
new image.  I put some data on a WWW page at
http://www.cv.nrao.edu/~awootten/hizmols.html

Let me know what y'all think.

Clear skies,
Al
+--------------------------------------------------------+
| Alwyn  Wootten   (http://www.cv.nrao.edu/~awootten/)	 |
| Project Scientist, The Millimeter Array                |
| Astronomer, National Radio Astronomy Observatory       |        
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