Summary of MD06.refstack.20121221

Similar to the MD06.GR0 (MD.GR0) refstacks for the 2011/2012 season, these include recent improvement and input cuts to help constrain the convolved stacks as well. Because the refstack is made with reprocessed pixels, the refstack pixels will now have the ubercalibration. Overall fewer inputs to the refstack were done this round and will not be excessively deep as last season.

MD06 observations:

• starting end December 2012 ?
• early January 2012 through mid-June 2012
• early January 2011 through end June 2011
• end December 2009 through end June 2010
• early April 2009 through end June 2009

Filter	N total	N FWHM<8 pixels	N (FWHM<8 pixels for 2011/2012
g
r
i
z
y

Status:

• 12/21 selected exposure reprocessing chip->warp for refstack started

MD06.V3 Processing (chip->warp + refstack)

Exposure reprocessing was done for only a limited number (~150) of the best images from 2010-2011 to provide a balance of N input warps versus best seeing, excluding exposures with large background, low zeropoints and large elongation.

Processing chip-warp and the refstack itself has the same label, data_group

• label: MD06.refstack.20121221 --> once set as active refstack for diffims, stack label will change to MD05.refstack, chip/cam/warp label will remain the same
• data_group: MD06.refstack.20121221

New ipp-20121218 tag used -- pswarp/ppStack bug fixed initially, but keep eye out. changes include:

• ?

Histograms of the FWHM major and minor and elongation from camera stage value (full exposure) for the sample of reprocessed exposures (red) and used for refstack.20121221 (top blue) and used for refstack.20111122 (bottom blue) in grizy order

Test stack (reftest) sample also made again for skycell.055 with different number of input warps.

• label: MD06.reftest.20121221
• data_group:
  • MD06.reftest.20121221.c#f<FWHM cut> where #=comparison run, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>
  • MD06.reftest.20121221.all.<FWHM cut> where all means 2009+2010+2011 data possible, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>
  • MD06.reftest.20121221.2010.<FWHM cut> where 2010 means 2010+2011 data only, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>

Summary comparison table with the approximate FWHM (major) as the PSF FWHM from a center field skycell (V3=055) after running psphot on the stacks.

| data_group                    | filter  | stack_id | warps_in | warps_rej |  FWHM_MAJ   IQ_FW1 (pixels)
+-------------------------------+---------+----------+----------+-----------+
--> 2012/2013 refstack

--> reftest comparisons			

--> previous 2011/2012 refstack		

As before, the FWHM_MAJOR with the central skycell can be variable and more so with largely different input sets. Comparison with the psf_major/minor maps are more useful between refstack versions.

Problems

• generally edge skycells have issues, need better containment of those still. (see Core coverage below).
• some convolved stacks have strange/poor FWHM PSF -- reprocessed using DEEP_STACK config with lighter input restrictions so may not have best FWHM, but 99% on the edge of field so won't anyways. Seems to be fewer problems compared to previous refstacks.
  • g: --
  • r: --
  • i: --
  • z: --
  • y: --
• bad cell arc in primarily skycell.033,024,025,026,047 y-band from ota14, cell 31. Not really seen in skycell.036 like others. ??
• poor/bad cell arc in primarily skycell.064 g-band (and less so in other filters) from ota43, cell 54? see MD10.refstack.20120705 where was in skycell.054. ??
• misc clusters of ghosts in g-band

Core coverage is the default set (CHECKING IF TRUE FOR MD06) {{ 82-87 x1-x8 12-17 }}}

• weaker (fewer inputs) for 012,017,021,028,071,078,082,087 in various filters
• using 2009 data in y-band and even in other years has provided some additional edge skycells in the refstack to be aware or wary of. Likely won't be covered enough for many diffims.
  • g:
  • r:
  • i:
  • z:
  • y:

Refstack Summary

Refstacks run through the staticsky (single filter mode so basic psphot with deteff measurements) and skycal stage on the unconvolved stacks to make the map plots (full 5 filter version still having occasional faults to work through):

• label: MD06.refstack.20121221, MD06.refstack.20121221
• data_group: MD06.refstack.20121221.1x201212xx, MD06.refstack.20121221.1x201212xx.cal201212xx

Source photometry psf_major,_minor maps (grizy):

Magnitude of sources@5-sigma maps (grizy):

Detection efficiency magnitude @50% recovery (500 fakes, grizy):