Summary of MD09.refstack.20130613

(back to MediumDeepFields summary)

Similar to the MD09.GR0 (MD.GR0) refstacks for the 2011/2012 season, these include recent improvement and input cuts to help constrain the convolved stacks as well. Overall fewer inputs to the refstack were done this round and may not be as deep as last season.

MD09 observations:

• starting late June 2013, pre-observations in late May and early-mid June
• early June 2012 through late Dec. 2012
• late June 2011 through early Dec. 2011
• late June 2010 through mid-Dec. 2010
• early June 2009 through end Sept. 2009
• (some 2008 but pre-survey)

Filter	N total	N FWHM<8 pixels	N (FWHM<8 pixels for 2012	N FWHM<6 pixels	N (FWHM<6 pixels for 2012
g	578	535	94	436	64
r	567	540	97	474	70
i	581	554	107	497	93
z	645	619	147	584	125
y	540	475	201	380	122

• 2012 wasn't a great season for MD09 either (like MD08)

Status:

• 04/0/13 selected exposure reprocessing chip->warp for refstack started (late due to power outage and messy system crashes)
• 04/14 reftests finished, full refstack started
• 04/15 refstack finished, checked and problem skycells found/fixed if possible. staticsky single filter only finished and mappings started
• 04/16 mappings finished, reftest+refstack to distribution
• 04/19? refstack setup, recently missed exposures setup for diffims

MD09.V3 Processing (chip->warp + refstack)

Exposure reprocessing was done for only a limited number (~150) of the best images from 2010-2012 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: MD09.refstack.20130613 --> once set as active refstack for diffims, stack label will change to MD09.refstack, chip/cam/warp label will remain the same
• data_group: MD09.refstack.20130613

The ipp-20130307 tag used still.

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.20130613 (top blue) and used for refstack.20120831 (bottom blue) in grizy order

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

• label: MD09.reftest.20130613
• data_group:
  • MD09.reftest.20130613.c#f<FWHM cut> where #=comparison run, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>
  • MD09.reftest.20130613.all.<FWHM cut> where all means 05/2010+2011+2012 data possible, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>
  • MD09.reftest.20130613.2012.<FWHM cut> where 2012 means 2012 data only for season stack example case, <FWHM cut>=cut <fwhm_major from camProcessedExp x10>
• the main field center shift was through ~Dec 2009, but is a very small shift. Excluding 2009 since usually not very good, or uncharacteristically too good (avoiding problems basically)
• c1 cuts

  filter: (FWHM set), elongation, zeropoint, background limits
  y: (3.6, 3.9, 4.1, 4.5), 1.3, 22.8, 4000 -- 
  z: (3.6, 3.7, 3.8, 4.0), 1.3, 24.0, 3000 --
  i: (3.9, 4.1, 4.2, 4.4), 1.25, 24.3, 2000 --
  r: (4.1, 4.3, 4.4, 4.6), 1.25, 24.3, 600 -- 
  g: (4.6, 4.8, 4.9, 5.1), 1.25, 24.3, 400 -- 
  

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)
+-------------------------------+---------+----------+----------+-----------+
--> 2013 refstack
MD09.refstack.20130613	y.00000	2254606	85	21	 3.21  2.99
MD09.refstack.20130613	z.00000	2254666	81	18	 3.32  2.71
MD09.refstack.20130613	i.00000	2254726	81	16	 3.65  2.94
MD09.refstack.20130613	r.00000	2254786	77	13	 4.16  3.41
MD09.refstack.20130613	g.00000	2254846	77	16	 4.52  3.70
	
--> reftest comparisons					
MD09.reftest.20130613.all.38	y.00000	2254481	77	18	 3.15  2.87
MD09.reftest.20130613.2012.41	y.00000	2254482	14	1	 3.57  3.18
MD09.reftest.20130613.all.37	z.00000	2254483	80	17	 3.29  2.67
MD09.reftest.20130613.2012.37	z.00000	2254484	10	1	 3.40  2.69
MD09.reftest.20130613.all.42	i.00000	2254485	94	21	 3.66  2.94
MD09.reftest.20130613.2012.42	i.00000	2254486	12	2	 3.58  2.97
MD09.reftest.20130613.all.43	r.00000	2254487	78	19	 4.08  3.33
MD09.reftest.20130613.2012.43	r.00000	2254488	8	1	 3.92  2.96
MD09.reftest.20130613.all.48	g.00000	2254489	76	20	 4.44  3.59
MD09.reftest.20130613.2012.48	g.00000	2254490	7	1	 4.50  3.42
MD09.reftest.20130613.c1f36	y.00000	2254491	33	9	 3.05  2.79
MD09.reftest.20130613.c1f39	y.00000	2254492	59	11	 3.14  2.91
MD09.reftest.20130613.c1f41	y.00000	2254493	85	22	 3.21  2.99
MD09.reftest.20130613.c1f45	y.00000	2254494	118	24	 3.31  3.12
MD09.reftest.20130613.c1f36	z.00000	2254495	39	4	 3.16  2.60
MD09.reftest.20130613.c1f37	z.00000	2254496	60	12	 3.28  2.66
MD09.reftest.20130613.c1f38	z.00000	2254497	81	17	 3.31  2.70
MD09.reftest.20130613.c1f40	z.00000	2254498	119	24	 3.41  2.79
MD09.reftest.20130613.c1f39	i.00000	2254499	39	6	 3.55  2.84
MD09.reftest.20130613.c1f41	i.00000	2254500	60	9	 3.61  2.91
MD09.reftest.20130613.c1f42	i.00000	2254501	81	16	 3.65  2.94
MD09.reftest.20130613.c1f44	i.00000	2254502	125	23	 3.82  3.05
MD09.reftest.20130613.c1f41	r.00000	2254503	33	7	 4.08  3.26
MD09.reftest.20130613.c1f43	r.00000	2254504	64	14	 4.17  3.39
MD09.reftest.20130613.c1f45	r.00000	2254505	95	16	 4.25  3.44
MD09.reftest.20130613.c1f46	r.00000	2254506	118	20	 4.30  3.51
MD09.reftest.20130613.c1f46	g.00000	2254507	31	5	 4.39  3.53
MD09.reftest.20130613.c1f48	g.00000	2254508	58	13	 4.45  3.61
MD09.reftest.20130613.c1f49	g.00000	2254509	77	16	 4.52  3.71
MD09.reftest.20130613.c1f51	g.00000	2254510	120	28	 4.59  3.80
	
--> previous 2012 refstack				
MD09.refstack.20120831	y.00000	1296416	87	17	 3.34  3.15
MD09.refstack.20120831	z.00000	1296692	102	29	 3.42  2.82
MD09.refstack.20120831	i.00000	1296762	89	16	 3.75  3.01
MD09.refstack.20120831	r.00000	1296831	92	18	 4.25  3.46
MD09.refstack.20120831	g.00000	1296901	97	27	 4.76  3.99

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

• as with all past refstacks, generally edge skycells have issues -- need better containment of those still. (see core coverage below).
• like others, greater % of inputs rejected (20-30%) so per pixel input is less, but still of order 30 inputs per pixel
• some convolved stacks have poorer FWHM PSF but not significant enough to be likely improved by reprocessing using DEEP_STACK config as in earlier MD fields
• g,i in particular seems to vaguely show the arc of shallower depth but no where close to what last year's refstack had?
• skycell notes:
  • y: s023,24,036,046,056 cell pattern; s060 conv prob; s068,071 high rej -- s060,071 replaced
  • z: s035 odd print through; s050 conv prob; s068 high rej % -- s050 replaced
  • i: s082 conv prob -- s082 replaced
  • r: s012 conv prob; s030,038 poor/conv prob -- s012,030,038 replaced
  • g: s012,030,050 conv prob; s021 poor; s024,027,032,033,037,065 strong ghost; s046 cell pattern -- s012,030,050,021 replaced

Core coverage -- one of the larger shifted pointings so very different from normal distribution of skycells (also see detection efficiency maps below)

082-086
071-077
060-068
050-058
040-048
030-038
021-027
012-016

• skycells with fewer inputs: (016g), 030, 038, 060, 068 , many more edge skycells in y-band; all ~50% or more

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: MD09.refstack.20130613, MD09.refstack.20130613
• data_group: MD09.refstack.20130613.1x20130615, MD09.refstack.20130613.1x20130615.cal20130615

Source photometry psf_major,_minor maps (grizy):

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

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

---

1D convolution mode

Full refstack -- run 20130905 (similar code version as MD02.refstack.20130815 with improved rejection)

• label: MD09.refstack.20130613_1dg
• data_group: MD09.refstack.20130613_1dg

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)
+-----------------------------------+---------+----------+----------+-----------+