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Wide Field Astronomy from Space. Steven Beckwith Space Telescope Science Institute January 9, 2002. F n (F n + DW B n ) 1/2. A Dn h n. ). (. 1/2. t 1/2. S/N = . Limits:. Space advantages: Low B n Small DW over FOV PSF stability Photometric stability Full sky coverage
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Wide Field Astronomy from Space Steven Beckwith Space Telescope Science Institute January 9, 2002
Fn (Fn + DW Bn)1/2 A Dn hn ) ( 1/2 t1/2 S/N = Limits: • Space advantages: • Low Bn • Small DW over FOV • PSF stability • Photometric stability • Full sky coverage • 24 hr operation • Ground advantages • Large area telescopes • Upgradable detectors (increase/repair FOV) • High survey speed at BLIP D = 6.5 m q = 0.3” D = 2 m q = l/D
GOODs Legacy & Treasury Programs • Observations • 300 arcmin2 in two fields: HDF-N, CDF-S • SIRTF: 3.6-24 µm (IRAC+MIPS), 600 hours • HST: 4 bands, 500 orbits ACS, near HDF depth • Chandra: 2x106 sec imaging; XMM: ~5x105 sec imaging • Science • Evolution of galaxies, 1 < z < 6 • SN Ia detection via scheduling • AGN morphologies • Potential upgrades: wider fields for AGN, weak-lensing, DEEP fields North South
All sky surveys • Space advantages: • Low Bn • Small DW over large FOV • PSF stability • Photometric stability • Full sky coverage • 24 hr operation • Ground advantages • Large area telescopes • Upgradable detectors (large FOV) • High survey speed at BLIP
Ideal limiting magnitudes Space-survey science: • Earth-crossing asteroids (sens.) • Kuiper-belt objects (sens., DW) • Transient sources • Supernovae (e.g. SN Ia) (sens.) • Micro-lensing sources (# stars) • Dwarf stars: white, brown (sens.) • Quantify weak lensing in distant galaxies (small DW, stable PSF) • Parallaxes of faint stars (sens.) • Rare objects (survey to R ~ 27m) • Eclipses of exo-planets (photometric stability) High z SN DMT 8.4m
SN Ia Detection rate 23 z = 1.0 24 LSST 4p 25 z = 1.4 I (mag) WFPC2: 2 orbit 26 z = 1.7 ACS: 2 orbit 27 28 -40 0 40 80 120 Dt (days)
” 0.080 SN 1998ff A. Riess, F. Boffi & SNaZ Team
Ingress Eclipse Egress HD 209458b: Exoplanet eclipse courtesy Brown et al. (2001) 3 hours 5x10-4 1σ ~ 2x10-4 Kepler selected as Discovery-class Mission
Globular Cluster 47 Tucanae courtesy R. Gilliland et al. (2001) • Contains about 106 stars, at ~11 Gyr HST/WFPC2 • Has a metallicity (abundance of elements heavier than helium) about one third that of the sun DSS
courtesy DMT consortium http://dmtelescope.org/science.html NEO Hazard
Cumulative Distribution of NEAs courtesy DMT consortium http://dmtelescope.org/science.html Follow-up problem ? 4,000 – 77,000 300m
Planned surveys with spacecraft • Galaxy, AGN evolution • HST/ACS, NGST • Supernovae, L • HST/ACS+NICMOS, SNAP • Eclipsing extra-solar planetary systems • Kepler • Astrometric surveys • Hipparcos, SIM, GAIA DW ~ l/D Bn ~ Zodiacal light FOV ~ optics limit