Title The CO-to-H2 conversion factor  
Pi     N. Nakai
Time   43 hrs

1. Name: The CO-to-H2 conversion factor
	Tatematsu, K., Nakai, N., et al.

   2. One short paragraph with science goal(s)

Indirect measurement of the mass of molecular gas from CO(1-0) intensity.
Of prime importance for all CO observations of any galaxies.
The conversion factor will be determined by using virial mass analysis
appling to individual molecular clouds.  How different (or common) is
the factor at various enviroment with different metalicities, 
arms/interarms, galactic centers, et al.?

   3. Number of sources

	6, from early to late type galaxies

   4. Coordinates:

      4.1. all over the sky (probably)

      4.2. Moving target: no

      4.3. Time critical: no

CO J=1-0 imaging:
----------------

   5. Spatial scales:

      5.1. Angular resolution (arcsec): 0.2"  (5 pc at 5 Mpc)

      5.2. Range of spatial scales/FOV (arcsec): three fields for each galaxies

      5.3. Single dish total power data: yes

      5.4. ACA: yes

      5.5. Subarrays: no


   6. Frequencies:

      6.1. Receiver band: Band 3

      6.2. Lines and Frequencies (GHz):
		CO 115.0 GHz (redshifted for 5 Mpc and Ho = 75)

      6.3. Spectral resolution (km/s): 2 km/s

      6.4. Bandwidth or spectral coverage (km/s or GHz): 1000 km/s max


   8. Line intensity:

      8.1. Typical value (K or Jy): 5 - 10  K

      8.2. Required rms per channel (K or Jy): 0.7 K

      8.3. Spectral dynamic range: 10

   9. Polarization:  no

   10. Integration time for each observing mode/receiver setting (hr):
		9.4 hr per a field of a galaxy

   11. Total integration time for program (hr): 9.4 x 3 x 6 = 169 hours

   12. Comments on observing strategy (e.g. line surveys, Target of
       Opportunity, Sun, ...): (optional)

Limit to only galaxies located at <5 Mpc to satisfy enough velocity resolution,
spatial resolution, and sensitivity for reasonable total observing time.

Will be important to observe early to extremely late type galaxies and
inner to outer disks of a galaxy.  So four field in each galaxy and
different type of ten galaxies would be needed.

********************************************************************

Review Chris Carilli: this is duplicate of 1.7.3
could combine or assume two groups are doing competing
experiments.

Comment Ewine: leave both program is DRSP, since there will be several attempts
to do this
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Review v2.0:
 
The CO to H2 conversion factor 
Tatematsu, Nakai et al. 

This seems to be a crucial ALMA goal. Would it make sense to expand
its scope to include all the SINGS spirals for example? What about
adding in higher-J transition maps? Note the Meier and Turner DRSP
proposal - would it make sense to combine these proposals into a
larger program on this issue?

1) Spectral line survey in high-z molecular absorption systems
2) A deep search for new molecular absorption systems
Wiklind, Combes

The revision to integration times seems fine. Are there any prospects
for boosting the target list further, from a southerly extension to
VLA/FIRST, from ATCA deep surveys etc? Perhaps the number of
candidates by the time the DRSP is implemented might be greater, and
the time required will grow? This could apply to both the 3 targets
destined for detailed study, and the number of flat-spectrum
candidates to search for the first time?