LIM Near IR from a minisatellite Dani Maoz

LIM: Near IR from a mini-satellite Dani Maoz

HST WFC 3 IR channel: 1 k x 1 k Hg. Cd. Te detector, QE 80% 18 micron pixels (0. 13”/pix), ~2’x 2’ FOV Detector sensitivity engineered to cut off above 1. 7 micron, so can operate at -128 C (6 -stage thermoelectric cooler) without thermal noise from telescope and detector. J (1. 1 micron) and H (1. 6 microns) bands. Dominant background: zodiacal light: 0. 6 -1. 3 e/s/pix Sensitivity: J=27 (ABmag, S/N=5) in 45 min (point src. ), 1. 4 hr (1” diam src. ) H=26. 4 53 min 1. 5 hr Sensitivity: J=26 (ABmag, S/N=5) in 10 min (point src. ), 18 min (1” diam. src. ) H=25. 4 12 min 19 min

HAWK-I on VLT: 0. 1”/pixel, 7. 5’ FOV 1 hr exposure : J=24. 9, H=23. 9 (S/N=5) i. e. 100 hrs exposure needed to reach WFC 3 1 -orbit depth! No place like space for NIR! 4 k pixels , 7. 4 cm

Why not make a “mini” (HST+WFC 3 -IR)/10? 2. 4 m 24 cm = 9. 5 in

For 24 cm aperture @ 1. 6 micron, diffraction limit: ~1. 3”. f/10 mirror, 18 -micron pixels 1. 5”/ pixel. Need ~100 hrs to get to HST-WFC 3 depth (same as VLT) BUT FOV can be much bigger! With 4 k x 4 k detector (like HAWK-I) FOV=1. 66 x 1. 66=2. 8 degree^2 = 2500 X WFC 3 ! A unique instrument for deep and wide NIR surveying. Science: Surveys for transients in NIR – High z and obscured regions

Survey Mode Examples: 1. All sky (1. 3 hr exposures): in 2 years, 2. to J=23. 4, H=22. 5 3. Ideal complement to LSST 2. 500 deg^2 transient search (180 fields, 1. 3 hr exposures), every 10 days to J=23. 4, H=22. 5. 3. 1 year: 10, 000 SNe Ia, 10, 000 CC-SNe 3. 30 deg^2 (10 fields, 30 -hr exposure), every 13 days to J=26, H=25. 4 1 year: 10, 000 SNe Ia, 10, 000 CC-SNe, z>1, z>2

Type-Ia SN delay time distribution

Two approved HST MC Treasury programs (1400 orbits) predictions by K. Sharon

predictions by K. Sharon

Payload logistics: Telescope Weight: Off-shelf Celestron 10” telescope ~40 kg -- can shave off with custom lightweight mirror Camera: few kg? To keep it simple/light/cheap: minimum optics, minimum moving parts, fixed filters on chips: J H H J H J H J J H Thermoelectric cooler: Weight ~0 Power consumption: ~250 W