1. Study of Gas Masses and Star Formation Efficiencies in Nearby Galaxies
J. Turner et al.

2. We will map CO (2-1) emission at 1.5" resolution in a
representative sample of nearby gas-rich (spiral and irregular)
star-forming galaxies. The goal is to do a detailed study of gas and
its relation to star formation. With CO gas masses, we can determine
star formation efficiencies on sizescales of 30-60 pc, using
ground-based Halpha images, radio continuum, and SIRTF photometry. We
choose CO (2-1) instead of the (1-0) transition to obtain simultaneous
1mm continuum measurements, which provides another constraint on gas
mass. We have chosen a representative range of Hubble types, galaxies
with and without starbursts; most of the galaxies have SIRTF GTO
programs for fIR photometry. We will map a 10'x10' region in each of
the galaxies; this will cover most of the galaxy at 20-50 pc
resolution.

3. Number of sources: 4

4. Coordinates:

	4.1 NGC1097 (interacting and strongly barred galaxy; 8'
                     diameter) 02h46m19.0s -30d16m30s
            M83     (starburst core, normal barred spiral; 12'
                    diameter) 13h37m00.9s -29d51m57s
            NGC5253 (dwarf E/S0 galaxy; efficient starburst;
                     5'x2') 13h39m55.9s -31d38m24s
	    NGC4945 (large spiral; 20'x4') 13h05m27.5s -49d28m06s
		
	4.2 Moving target: no
	4.3 Time critical: no
	
5. Spatial scales:
	5.1 Angular resolution: 1.5"
	5.2 Range of spatial scales/FOV:  ~10' fields: require 40^2=1600 point mosaics for each, OTF 
	mapping (some galaxies will have rectangular maps along their disks) Images contain 400x400 beams.
	5.3 Single dish: yes
	5.4 ACA: yes
	5.5 Subarrays: no
	
6. Frequencies:
	
	6.1	Receiver band: Band 6
	6.2	Continuum
	6.3	Spectral resolution 4 km/s
	6.4 	Spectral coverage 600 km/s
	
7. Continuum flux density

	7.1	Typical value 0
	7.2 	Continuum peak value: 50 mJy
	7.3 	Required continuum rms: 0.1 mJy/beam
	7.4 	Dynamic range in image:  500:1
	
8. Line Intensity 

	8.1 	Typical value: 0.5 K (up to 20K)
	8.2 	Required rms value per channel: 0.05 K 
	8.3	Spectral dynamic range: 400:1
	
	
9. Polarization  N/A

10. Integration time per setting: 1 minute per Nyquist setting, 1600
settings within a 10'x10'
	region, mosaic/OTF mode. Total integration time, without
calibration, 1600 minutes =
	27 hrs/galaxy. 4 galaxies x 30 hours = 120 hours about 5 days
w/o calibration, slew, rampup.

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Review Chris Carilli: OK, but possibly overestimates required time by
factor 2 since this is a mosaic.  The sensitivity they quote is per
1min pointing, but the pointings overlap. However, program is only 120
hrs total, so leave as-is.