1. Name of program and authors

Follow-up observations of very bright Planck Surveyor sources

Andrew Blain

   2. One short paragraph with science goal(s)

There is no all-sky submm survey. IRAS, and the forthcoming IRIS/ASTRO-F
mission, have mapped large areas of the sky, but at longer wavelengths
the brightest examples of the submm galaxy population have not been
cataloged. This should change after 2007/8 when the Planck Surveyor
satellite surveys the whole sky at 850, 500 and 350 microns at 5-arcmin
resolution, detecting objects as faint as several 100mJy.
It is unclear how deep the survey will go, but it is likely that at
least 10,000 sources will be detected. These will be a mix of relatively
low-redshift, low-luminosity sources and the most luminous galaxies in
the Universe. 10% of them could be gravitationally lensed by at least a
factor of 2 by foreground galaxies.

These objects will be bright and easy to study by ALMA. This proposal
assesses the time required to locate, image and study these galaxies,
revealing the astrophysics in the most extreme objects known.
In parallel, a wide-field, shallow imaging survey of order 70 square
degrees will be made.

   3. Number of sources
Of order 20,000 galaxies over the whole sky, about 30% eclipsed by the
Milky Way, and 40% inaccesible from the ALMA site. So 10,000 targets

   4. Coordinates:
      4.1. Rough RA and DEC
Should be approximately uniform (except the Milky Way region)
No clustering, but avoiding 04-09hr.
      4.2. Moving target: no  (e.g. comet, planet, ...)
      4.3. Time critical: no  (e.g. SN, GRB, ...)

   5. Spatial scales:
      5.1. Angular resolution (arcsec): 0.01"-1"
      5.2. Range of spatial scales/FOV (arcsec): 0.01-10" 
		5' field mosaic and then single field when object located
      5.3. Single dish total power data: no
      5.4. ACA: no
      5.5. Subarrays: NO (single array always faster)

   6. Frequencies:
      6.1. Receiver band:=20
Band 6 to scan the field for a detection - most rapid, due to a
combination of expected SED, primary beam area and source SED. The
SED can be estimated from Planck bands, along with ASTRO-E upper limits/
detections. 

Follow up imaging in all 4 bands, to determine color distributions, and
accurate SEDs.
Three tunings in band-3 to search 24GHz for CO lines: detect redshifts
for ~30% of sources.

      6.2. Lines and Frequencies (GHz): 230-GHz imaging in band-6 

      6.3. Spectral resolution (km/s):> 300 km/s

      6.4. Bandwidth or spectral coverage (km/s or GHz): 8 GHz

   7. Continuum flux density:

      7.1. Typical value (Jy):
	For typical galaxy SED at moderate redshift
	 90GHz 	 1 mJy
	230GHz	50 mJy
	350GHz	100 mJy
	670GHz	300 mJy

SED will be revealed from Planck, so can hone object by object if desired.

      7.2. Required continuum rms (Jy or K):
	Search at 230GHz - need rms 5mJy or less.
	Imaging at other wavelengths - need good quality image:
	 90GHz	0.05mJy
	230GHz	1mJy
	350GHz	2mJy
	670GHz	2mJy

      7.3. Dynamic range within image:                 
		Small. 100. All bright objects

   8. Line intensity:
	Uncertain, should be detectable, but redshifts not known - should be
	easy to search band 3 for CO emission in a matter of seconds.

      8.1. Typical value (K or Jy):
	N/A ~1 Jy over 300 km/s channel in band 3.

      8.2. Required rms per channel (K or Jy):
	N/A - set by continuum

      8.3. Spectral dynamic range:
	N/A - small

   9. Polarization: 
	Might be possible for these bright objects to search for signs of AGN.

      9.1. Required Stokes
		Just 2
      9.2. Total polarized flux density (Jy)
SG: much less than this		0.1Jy
      9.3. Required polarization rms and/or dynamic range
		3%
      9.4. Polarization fidelity
		Not a big issue

   10. Integration time for each observing mode/receiver setting (hr):
	230GHz - 30 images to cover 5-arcmin pixel - each 5mJy RMS (0.15s)=4.5s
	Imaging on target -
	90GHz - 	40s (x3 tunings)
	230GHz - 	<10s
	350GHz - 	<10s
	670GHz -	15s
	<3 minutes each. 

	Will be dominated by overheads for slewing/scanning etc... deeper imaging of detected sources possible.

   11. Total integration time for program (hr):

10,000 sources (estimated) = up to 500 hours

   12. Comments on observing strategy (e.g. line surveys, Target of
       Opportunity, Sun, ...): (optional)
SG:	OTF mosaic required to minimize time losses in initial search.
	Other parts require grouping by frequency range, all sources together, to minimize
	overheads too.

Time spent could be a 20% higher for larger numbers of spectral line
searches, higher quality imaging etc.

The request can be modified when the numbers and ease of detection/
overheads issues are all resolved once ALMA is in operation.


Review Chris Carilli: OK, integration times checked, but again a large
program (500 hrs for 10000 sources). Unclear we really need to
followup ALL Planck bright sources.  again, cut in 2 to 4 for
'representative sample.'

Comment Ewine: program kept at 500 hr in current DRSP version since
integration times per source are short => fewer number of sources will
be compensated by larger overhead when that is taken into account in
next DRSP version