LIM: Near IR from a mini-satellite Dani Maoz

HST WFC3 IR channel: 1k x 1k HgCdTe detector, QE 80% 18 micron pixels (0.13”/pix), ~2’x2’ 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: e/s/pix Sensitivity: J=27 (ABmag, S/N=5) in 45 min (point src.), 1.4 hr (1” diam src.) H= min 1.5 hr Sensitivity: J=26 (ABmag, S/N=5) in 10 min (point src.), 18min (1” diam. src.) H= min 19min

4k pixels, 7.4cm 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 WFC3 1-orbit depth! No place like space for NIR!

Why not make a “mini” (HST+WFC3-IR)/10? 2.4m 24cm = 9.5 in

For 24 cm 1.6 micron, diffraction limit: ~1.3”. f/10 mirror, 18-micron pixels  1.5”/ pixel. Need ~100 hrs to get to HST-WFC3 depth (same as VLT) BUT FOV can be much bigger! With 4k x 4k detector (like HAWK-I) FOV=1.66x1.66=2.8 degree^2 = 2500 X WFC3 ! 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 (1.3hr exposures): in 2 years, to J=23.4, H=22.5 Ideal complement to LSST deg^2 transient search (180 fields,1.3hr exposures), every 10 days to J=23.4, H= year: 10,000 SNe Ia, 10,000 CC-SNe deg^2 (10 fields, 30-hr exposure), every 13 days to J=26, H= 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

Payload logistics: Telescope Weight: Off-shelf Celestron 10” telescope ~40kg -- 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 J J J J J J J HH H H H H H H Thermoelectric cooler: Weight ~0 Power consumption: ~250 W