Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.apo.nmsu.edu/arc35m/Instruments/ARCTIC/Development/ImagerPDR/SpicamScience.pdf Äàòà èçìåíåíèÿ: Thu Dec 5 20:44:06 2013 Äàòà èíäåêñèðîâàíèÿ: Thu Feb 27 21:03:47 2014 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: barnard 68

APO Imager
(science background, goals and overview)

· History of science with SPIcam. Its usage and publications for the past 5 years. · Filter usage for the past 5 years · Compelling reasons to retire SPIcam · Review of current design requirements · Comparison of CCD choice with current APO imagers (SPIcam and AGILE) · Potential science improvements with new imager


Seaver Prototype Imaging Camera
(SPIcam) Developed and built by Engineering Group at UW (PI: C. Stubbs)1 Delivered to the 3.5-m, September 1997 SITe / TK2048E CCD, 2048x2048, 24µm pixels (similar to the Sloan Imager chips which were TK2048D) Cooled with a Brooks Automation Polycold Compact o Cooler (PCC or Cryotiger) to 163K (-110 C) 6 position filter wheel (4 copies) for large compliment of 3x3 inch2 and 2x2 inch2 broad and narrow bandpass filters (~200 total available in the on site catalog)
1.Thanks to the generous support of the Seaver Institute and the David and Lucille Packard Foundation who made construction of this instrument possible.


SPIcam Instrument Usage
(October 1 - September 30)

Scheduled Usage (Hours) Percentage
[Competing Instruments]

2013 (300)
8.5%
[D/E/N/P/T] V(~6%)=G,A

2012 (274)
8.0%
[D/E/N/P/T] V(6%)=G,A,NIIS

2011 (431)
11.7%
[D/E/N/P/T] V(6.3%)=G,A

2010 (404)
10.9%
[D/E/N/P/T] V(4.8%)=G,A

2009 (285)
8.7%
[D/E/N/P/T] V(5.7%)=G,A,NAIC

Scheduled Usage (Hours) Percentage
[Competing Instruments]

2008 (511)
13.7%
[D/E/N/P/T] V(5.1%)=G,A

2007 (555)
15.4%
[D/E/N] V(10.2%)=C,G,A,P ,NAIC

2006 (542)
15.1%
[D/E/N] V(10.6%)=C,G,A

2005 (441)
12.7%
[D/GRIM/E/N] V(5%)=C,G,A,NAIC

2004 (378)
13.1%
[D/GRIM/E/N] V(5%)=C,G

Scheduled Usage (Hours) Percentage
[Competing Instruments]

2003 (729)
25%
[D/GRIM/E] V(7%)=G,AOTF

2002 (576)
20%
[D/GRIM/E] V(9%)=G,AOTF,L

2001 (401)
14%
[D/GRIM/E] V(8%)=G,AOTF,L

2000
(195*)
(*=half nights)

1999 (353)
17.7%
[D/GRIM/E] V=AOTF

28.8%
[D/GRIM/E] V(11%)=G,AOTF,L,I

Instrument codes: DIS[D], Echelle[E], GRIM2[GRIM], NicFPS[N], Agile[P], Triplespec[T], Visiting(V), GIFS/GFP(G), APOLLO(A), CorMASS (C ), NAIC, NIIS, InSb(I), LL FTS (L) Note: Facility instruments in [ ] Statistics from Annual Reports to ARC Board of Governors 1999-2012



Solar System Science with SPIcam
(compiled from Q42008 - Q42013 science schedule and proposals)

· · · · · · ·

Outer solar system bodies (TNOs) (18 proposals in 14 quarters = 138.3 hours) Shapes and sizes of Cometary Nuclei (15 quarters = 103.7 hours) Pan-STARRS follow-up of comets (7 quarters = 65.7 hours) Asteroid classifications (4 quarters = 52 hours) Binary asteroids (3 quarters = 30.96 hours) Comet compositions and activities (3 quarters = 20 hours) Near earth asteroid astrometry (1 quarter = 13 hours)


Galactic Science with SPIcam
(compiled from Q42008 - Q42013 science schedule and proposals)

· · · · · · · ·

Exoplanetary transits (9 proposals in 5 quarters = 100.4 hours) Eclipsing binaries in stripe 82 of SDSS survey (7 quarters = 83.9 hours) Globular cluster photometry to calibrate StrÆmgren filter set (8 quarters = 56.1 hours) Low mass eclipsing binary photometry (1 quarter = 13.4 hours) Halpha/Hbeta study of planetary nebula (1 quarter = 11.9 hours) Red Square Nebula (2 quarters = 7.1 hours) Star formation in our galaxy (1 quarter = 6.6 hours) Pulsar companions (2 quarters = 5.6 hours)


Extragalactic Science with SPIcam
(compiled from Q42008 - Q42013 science schedule and proposals)

· · · · · · · · · · · ·

SDSS follow-up star formation in dwarf sphericals + irregulars (15 quarters = 268.9 hours) Photometric redshift survey of galaxies in line of sight of QSOs (10 quarters = 181.9 hours) Atacama Cosmology Telescope optical follow-up (various) (4 quarters = 83.5 hours) Gravitational Lenses (8 quarters = 69.9 hours) Pan-STARRS follow-up of supernovas (7 quarters = 65.7 hours) Properties of Galaxies (7 quarters = 57.2 hours) Galaxy evolutions in compact groups (3 quarters = 52 hours) Dwarf Galaxy studies and mergers (5 quarters = 32 hours) Dwarf irregular metalicity mapping with StrÆmgren filters (2 quarters = 31.5 hours) Star formation in cores of galaxy clusters (5 quarters = 27.3 hours) Star formation in galaxies (3 quarters = 22.75 hours) Follow-up transits from SDSS SN survey looking for GRB afterglows (1 quarter = 13.3 hours)


Extragalactic Science with SPIcam
(continued) (compiled from Q42008 - Q42013 science schedule and proposals)

· · · · · · · · · · · ·

Arecibo optical follow-up (2 quarters = 12.6 hours) Nearby low surface brightness galaxies near QSO sight lines (1 quarter = 10.8 hours) Tidal Formations in galaxies (2 quarters = 10.6 hours) SDSS Stripe 82 supernova follow-up (2quarters = 10 hours) Black Holes (2 quarters = 9 hours) Mapping the circum-galactic medium with QSOs (1 quarter = 6.6 hours) Diffuse stellar light at center of massive clusters (1 quarter = 6.5 hours) Star Bursting Blue Compact Galaxies in Intermediate Redshift Clusters (1 quarter = 6.4 hours) Wolf-Rayet Galaxies (1 quarter = 5.5 hours) Intercluster medium (1 quarter = 5.1 hours) Metalicities of galaxies with historical SN (1 quarter = 4.7 hours) Quasar discovery (1 quarter = 2.9 hours)


Publications based on SPIcam Data
(Papers and Theses, 11/2010-11/2012) Churchill, C. W., Kacprzak, G. G., Steidel, C. C., Spitler, L. R., Holtzman, J. A., Nielsen, N. M., & Trujillo-Gomez, S. 2012, "Quenched Cold Accretion of a Large Sacle Metal Poor Filament due to Virial Shocking in the Halo of a Massive z=0.7 Galaxy", ApJ, accepted, arXiv:1205.0595 Bhatti, Waqas, 2012, "Testing Low-mass Stellar Models with M-dwarf Eclipsing Binaries from SDSS Stripe 82", Ph.D. Thesis, JHU (Advisor: Holland Ford) Davenport, J.R.A., Becker, A., West, A.A., Bochanski, J.J., Hawley, S.H., Holtzman, J., Gunning, H.C., Hilton, E.J., Munshi, F.D., Albright, M., 2012, "The Very Short Period M Dwarf Binary SDSS J001641-000925", submitted to ApJ Grundy, W.M., et al., 2012, "Mutual Events in the Cold Classical Transneptunian Binary System Sila and Nunam", Icarus, 220, 74 Hart, Q.N., Stocke, J.T., et al., 2011 "The evolution of radio galaxies and X-ray point sources in Coma Cluster progenitors since z~1.2", ApJ 740, 59 Hughes, J., Wallerstein, G., 2011, "Determining the photometric metallicities of dSph stellar populations", arXiv:1108.5020 Jackson, N., et al., 2012, "New lensed quasars from the MUSCLES survey", MNRAS 419, 2014 Kacprzak, G. G., Churchill, C. W., Steidel, C. C., Spitler, L. R., & Holtzman, J. A. 2012, "Discovery of MultiPhase Cold Accretion in a Massive Galaxy at z=0.7", MNRAS, accepted, arXiv:1208.4098 Menanteau, F., et al., 2012 "The Atacama Cosmology Telescope: Physical Properties of Sunyaev-Zel'dovich Effect Clusters on the Celestial Equator", submitted to ApJ., archiv 1210.4048 (1) Patterson, Maria T.; Walterbos, Rene A. M.; Kennicutt, Robert C.; Chiappini, Cristina; Thilker, David A., 2012, "An Oxygen Abundance Gradient into the Outer Disc of M81", MNRAS, 422, 401


Publications based on SPIcam Data
(Papers and Theses, 11/2009-11/2010) Blackburne, J.A., Kochanek, C.S., 2010, "The Effect of a Time Varying Accretion Disk Size on Quasar Microlensing Light Curves", submitted to ApJ., astro-ph/1002.3126 Diehl, H.T., Allam, S.S., Annis, J., Buckley-Geer, E.J., Frieman, J.A., Kubik, D., Kubo, J.M., Lin, H., Tucker, D., West, A., 2009, "The Sloan Bright Arc Survey: Four Strongly Lensed Galaxies with Redshift > 2", ApJ, 707, 686. Dilday, B., etal., 2010, "Measurements of the Rate of Type Ia Supernovae at Redshift <~ 0.3 from the Sloan Digital Sky Survey II Supernoae Survey", ApJ, 713, 1026 Hart, Q., 2009, "AGN in Clusters of Galaxies", Ph.D. thesis, Univ of Colorado, Dec 2009 Hart, Q.N., Stocke, J.T., Hallman, E.J., 2009, "X-ray Point Sources and Radio Galaxies in Clusters of Galaxies", ApJ, 705, 854 Keeney, B.A., Stocke, J.T., Danforth, C.W., Carilli, C., 2010, "The Quasar/Galaxy Pair PKS 1327-206/ESO 1327-2041: Absorption Associated with a Recent Galaxy Merger", submitted to AJ, astro-ph/1009.5993 McGreer, I.D., etal., 2010, "SDSS J094604.90+183541.8: A Gravitationally Lensed Quasar at z= 4.8", AJ, 140, 370 Rest, A., etal.., 2010, "Direct Confirmation of the Asymmetry of the Cas A SN Explosion with Light Echoes", submitted to ApJ, astro-ph/1003.5660


Publications based on SPIcam Data
(Papers and Theses, 11/2008-11/2009) Coughlin, J.L., Stringfellow, G.S., Becker, A.C., Lopez-Morales, M., Mezzalira, F., Krajci, T., 2008, "New Observations and a Possible Detection of Parameter Variations in the Transits of Gliese 436b", ApJ 689, L149 Holtzman, J., et al., 2008, "The Sloan Digital Sky Survey-II: Photometry and Supernova Ia Light Curves from the 2005 Data", AJ, 136, 2306 Holtzman, J., Eisenstein, D., Strauss, M., York, D., Anderson, K., Walterbos, R., Klaene, M., Gillespie, B., Anderson, S., Turner, E., 2009, "Apache Point Observatory: Facilities, Operations, and Partnerships", Astro2010: The Astronomy and Astrophysics Decadal Survey, Position Papers, no 23 Hughes, J., Wallerstein, G., Bossi, A., 2008, "The Age and Metallicity of the Bootes I System", AJ 136, 2321, astro-ph/0810.4353 Inada, N., Oguri, M., Shin, M.-S., Kayo, I., Strauss, M.A., Morokuma, T., Schneider, D.P., Becker, R.H., Bahcall, N.A., York, D.G., 2008, "Five New High-Redshift Quasar Lenses from the Sloan Ditial Sky Survey", AJ, 137, 4118, astro-ph/0809.0912 Kubo, J.M., Allam, S.S., Annis, J., Buckley-Geer, E.J., Diehl, H.T., Kubik, D., Lin, H., Tucker, D., 2009, "The Sloan Bright Arc Survey: Six Strongly Lensed Galaxies at z = 0.4 - 1.4", ApJ, 696, L61 LIn, Huan, Buckely-Geer, Elizabeth, Allam, Sahar S., et al., 2009, "Discovery of a Very Bright, Strongly-Lensed z=2 Galaxy in the SDSS DR5", ApJ, 699, 1242 astro- ph/0809.4475 Miller, C., Chanover, N.C., 2009, "Resolving Dynamic Parameters of the August 2007 Titania and Ariel Occultations by Umbriel", Icarus, 200, 343 Stringfellow, G.S., Coughlin, J.L., Lopez-Morales, M., Becker, A.C., Krajci, T., Mezzalira, F., Agol, E., 2009, "Transit Timing Observations of the Extrasolar Hot-Neptune Planet GL436b", in Cool Stars, Stellar Systems, and the Sun, AIP Conf. Proc. 1094, 481


Publications based on SPIcam Data
(Papers and Theses, 11/2007-11/2008) Anguita, T., Schmidt, R.W., Turner, E.L., Wambsganss, J., Webster, R.L., Loomis, K.A., Long, D., McMillan, R., 2008, "The Multiple Quasar Q2237+0305 Under a Microlensing Caustic, A&A 480, 327 Dilday, B., Kessler, J.A., Frieman, J., Holtzman, J., etal., 2008, "A Measurement of the Rate of Type-Ia Supernovae at Redshift z ~ 0.1 from the First Season of the SDSS-II Supernova Survey", ApJ 682, 262 Frieman, J., etal, 2008, "The SDSS-II Supernova Survey: Technical Summary", 2007, AJ. 135, 338 (astroph/0708.2749) Morgan, C.W., Kochanek, C.S., Dai, X., Morgan, N.D., Falco, E.E., 2008, "X-Ray and Optical Microlensing in the Lensed Quasar PG 1115+080", ApJ 689, 755 Nitta, A., Kleinman, S.J., etal, 2008, "New Pulsating DB White Dwarf Stars from the Sloan Digital Sky Survey", ApJ, in press, astro-ph/0809.0921 Oguri, M., Inada, N., Clocchiatti, A., Kayo, I., Shin, M., Hennawi, J., Strauss, M.A., Morokuma, T., and Schneider, D. 2008, "Discovery of Four Gravitationally Lensed Quasars from the Sloan Digital Sky Survey", AJ 135, 520 Sako, M., etal, "The SDSS-II Supernova Survey: Search Algorithm and Follow- up Observations", 2008, AJ, 135, 348 (astro-ph/0708.2750) Wang, X., etal., 2008, "Optical and Near-Infrared Observations of the Highly Reddened, Rapidly Expanding Type Ia Supernova 2006X in M100", ApJ 675, 626, astro- ph 0708.0140


SPIcam filter usage
Bro ad Ban d pas s Fi l t ers
MS S S O U MS S S MS S S MS S S MS S S SDSS SDSS O O O O u g B V R I Si z e (i n ) 3x 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 3 x x x x x x x x x x x x x x x x x x x x x x x x 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 3
2

2013
2 .8 5 0 6 .4 2 2 2 .8 1 9 .2 8 1 .7 1 2 .3 2 2 5 .4 5 1 0 .5 2 4 .2 7 0 0 0 .9 2 0 0 1 .3 2 3 .6 9 0 0 0 .3 0 .5 5 0 .4 0 .3 7 0 0

2012
1 .2 5 0 .3 0 .8 7 3 5 .3 5 .9 6 3 5 .9 8 1 0 .5 9 1 4 .1 4 5 .3 0 0 .8 2 2 .0 9 1 .3 1 0 3 .5 1 9 .5 9 0 0 0 0 0 0 0 0

2011
0 .1 7 0 .0 7 5 .9 7 2 2 .4 9 4 .6 8 5 .4 3 7 .3 7 1 2 .1 8 5 .4 1 6 .2 5 0 0 3 .4 5 3 .2 1 0 .7 5 3 .6 1 0 .5 8 0 0 0 .2 6 0 0 .5 2 0 0 0 .0 1

2010
0 .1 2 0 .0 4 0 .0 3 9 .8 7 3 .3 9 1 0 .7 1 1 0 .2 5 1 9 .6 3 9 .0 1 9 .9 0 .9 1 0 0 .5 0 .8 9 1 .7 2 0 .5 5 4 .8 6 1 .6 6 2 .6 1 0 0 0 0 0 0 .2 4

2009
0 0 .2 5 6 .4 1 1 0 .6 9 1 .2 2 .1 4 7 .3 4 6 .2 1 8 .9 9 8 .0 3 0 0 6 .8 3 1 3 .1 8 0 .0 4 8 .4 9 1 .2 0 0 0 0 0 0 1 .3 5 0

SDSS r SDSS i SDSS z H ar ris R ( 6 4 7 2 /1 4 5 8 ) B G4 0 ( 4 7 5 0 /3 1 0 0 ) St rÆ m gren y (5 4 5 0 /1 5 0 ) St rÆ m gren v (4 1 0 0 /2 0 0 ) St rÆ m gren u (3 5 0 0 /3 0 0 ) St rÆ m gren b (4 7 0 0 /2 0 0 ) W as h i n gt on C ( 4 0 0 0 / 1 0 0 0 ) W as h i n gt on M ( 5 0 0 0 /1 2 0 0 ) W as h i n gt on T 2 C om et F ilt e r s C 2 C om et F ilt e r s C N C om et F ilt e r s B C 4 H al e B o pp R C 3 Gu n n -g OP EN/C LEA R

S u bt o t al (%)

93.18

100.01

92.4

86.89

82.35

Compiled from instrument logs (Oct 1 - Sep 30) *Flats excluded


SPIcam filter usage
Nar ro w Ban d p as s F i l te rs
C U S II (6 7 2 5 / 9 0 ) C U Ha (6 5 6 3 / 9 0 ) A PO H a (6563/ 100) H o d g e H a ( 6 5 6 3 / 25 ) Ho dge 6 6 2 9 /2 5 Ho dge 6 6 0 7 /2 0 Ho dge 6 5 8 5 /2 0 Ho dge Hb (4 8 6 0 /2 5 ) NM SU 6776/75 NM SU 6736/80 NM SU 6676/75 NM SU 6650/80 NM SU 6610/75 NM SU 6580/25 NM SU 6570/75 NM SU 6550/80 NM SU 6450/100 NM SU 5007/60 D D O -5 1 5 1 3 0 / 1 54 UW -W S U 4 6 8 6 / 6 0 Si z e (i n ) 3 3 2 2 2 2 2 2 2 2 2 x x x x x x x x x x x 3 3 2 2 2 2 2 2 2 2 2
2

2013
0 0 0 .0 3 0 0 0 0 0 0 0 0 2 .6 3 0 .9 3 0 1 .1 7 0 2 .0 6 0 0 0

2012
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

2011
0 0 3 0 0 0 .1 .1 .3 .5 .2 .5 0 0 0 .2 0 .2 0 8 8 4 2 4 4

2010
1 .9 1 0 .8 0 0 0 0 0 0 1 .7 4 0 .2 6 0 2 .0 1 0 .3 4 0 1 .3 0 1 .3 4 0 3 .4 0

2009
0 .6 4 0 .6 2 0 0 .1 8 0 .2 3 0 0 3 .8 5 2 .4 6 0 .7 9 0 2 .1 4 1 .1 9 0 1 .3 7 0 .1 6 1 .6 9 2 .3 5 0 0

5 5

2x 2 2x 2 2x 2 2x 2 2x 2 2x 2 2x 2 2x 2 2x 2

0 .6 7 0 .5 2 0 .2 0 0 0 .2 6 0 0 0 .4 7

S u bt o t al (%) To t al ( %)
( b r oad b an d + n ar r o w b an d )

6.82 100

0 100.01

7.62 100.02

13.1 99.99

17.67 100.02

Compiled from instrument logs (Oct 1 - Sep 30) *Flats excluded


SPIcam Retirement
· · · · · Lack of documentation Minimal serviceability of electronics Noise issues (pattern and ion pump induced dark current, see below) Long readout times between exposures (120s Full frame, unbinned or 42s Full frame, binned 2x2) Starting to see more bad columns / charge traps appear

Normal 900s dark

Pickup noise examples (darks and biases)

ion pump induced noise


Design Requirements Review
In March 2013, a proposal for an imager on the APO 3.5m telescope was presented to the users committee. This proposal outlined several options for a general-purpose optical imager to replace the aging and hard to maintain SPICam. Feedback and discussion over the last couple months has allowed us to make some design decisions. From this feedback it was determined that the most important properties of this imager should include good throughput, good spatial resolution, fast readout, and capability to use narrow band filters (both existing and new).Many institutions felt that the proposed widest field option (~12'x12' FOV) would not present a significant scientific advantage compared to the increased cost of the detector. Other design requirements included: ­ ­ ­ ­ ­ ­ ­ ~ 9'x9' FOV using focal reduction (same 4.7'x4.7' FOV using 3x3 inch and 3'x3' FOV using 2x2 inch filters that SPIcam currently gives) NA2 mounted compact instrument (at first), must meet all the 20 question requirements document of a visiting or facility instrument Leach electronics Cryotiger cooling Photometric precision shutter Low read noise and negligible dark current RMS spot sizes less then typical seeing disk of 1 arc-second but goal of 0.75 arcsecond seeing


CCD Chip coating(1) Format Pixel Size Imaging Area Dark Current (@ ~ 170K) Readnoise Gain Full Well Depth Read out time Peak QE (@350nm)(1) Peak QE (@400nm)(1) Peak QE (@600nm)(1) Peak QE (@800nm)(1) f/ratio Field of View Pixel Scale Operating Temperature (K) Limiting Magnitude (Mag for griz w/ 300s results in S/N = 10) Fringing(3) Note (1) See QE Curves (next page) Note (2) To be named Note (3) See fringing plot

Imager(2) e2v CCD 231 w/ fringe suppression DD Astro Broadband 4096(H) x 4112(V) 15µm x 15µm 61.4mm x 61.4mm 3e-/pixel/hour 5 e-/sec @ 1MHz 2 e /sec @ 50KHz 2.6 e /DN 350Ke4.2 seconds @ 1MHz full frame no binning 84 seconds @ 50kHz full frame no binning 55% 81% 80% 69% 8 7.6 arcmin x 7.6 arcmin 0.111"/pixel 160K ? (Background Limited)

SPIcam SITe/TK2048E VIS AR 2048 x 2048 24µm x 24µm 49mm x 49mm 3.6 e-/pixel/hour 5.7 e-/sec 3.36 e /DN 150Ke120 seconds full frame binned 1x1 42.3 seconds full frame binned 2x2 48% 84% 88% 76% 10.3 (native telescope) 4.7 arcmin x 4.7 arcmin 0.141"/pixel (typically binned 2x2) 160K ? (Background Limited) None
-

AGILE e2v CCD 47-20 Frame Transfer Device Broadband AR 1024 x 1024 (Active and Storage) 13µm x 13µm 13.3mm x 13.3mm 13.3 e-/pixel/second 6.62 e-/sec @ 1MHz 3.66 e /sec @ 100kHz Selectable: (0.9 - 4) e /DN 100Ke 0.46 seconds @ 1MHz full frame binned 2x2 3.1 seconds @ 100kHz full frame binned 2x2 38% 64% 98% 80% ~6.1 2.2 arcmin x 2.2 arcmin 0.129"/pixel (typically binned 2x2) 233K (-40C) ? (Readnoise Limited) None





This figure shows fringe response for an AR coated back illuminated deep depletion device. With the addition of fringe suppression and an AR coating the fringe amplitude would decrease to 1-2% per discussions with e2v.


Anticipated Performance Improvements with new Imager
· · More accurate shutter for shorter exposure times (10ms accuracy expected for as short as 0.5sec exposures) Shorter overall exposure times by approximately a factor of 2.5
­ Focal Reduction from f/10.3 to f/8 (m = 0.95) increases the image surface brightness per pixel and shortens exposures by factor of (1/m)2 = 1.1 ­ Standard binning of 3x3 will reduce the exposure time by a factor of 2.25 times (9/4 = 2.25) compared to the same exposure using SPIcam with 2x2 binning.


Increased Science Potential with new Imager
· · · · · · ·
·

Larger FOV for select solar system science Larger FOV for comparison stars when doing differential photometry Larger FOV for imaging of globular or open clusters Larger FOV for imaging nebulas and galaxy clusters Larger FOV time series photometry (than AGILE in slow readout rate) given faster chip readout (full frame and sub-regions) Potential of much larger narrow band imaging projects (requiring purchase of larger filters dependant on science goals) Measurable sky or more foreground stars available in the image when studying nearby galaxies
Other? Depends on the imagination and science interests of our various users