Wide Field Astronomy from Space Steven Beckwith Space Telescope Science Institute January 9, 2002
1/9/20022 Limits: Space advantages: Low B Small 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 S/N = t 1/2 A h F (F + B ) 1/2 1/2 ( ) D = 6.5 m = 0.3 ” D = 2 m = /D
1/9/20023 ACS Survey Workshop Motivation: Motivation: To determine the potential for new surveys with ACS To identify areas for teaming on large initiatives Discussion findings: Discussion findings: Obvious synergism between galaxy formation, AGN evolution, weak lensing, and cosmology (SN Ia) in need for a ~1 ° HDF-like survey Recognition of multiple science potential of deep and wide surveys with HST March 2001
1/9/20024 GOODs Legacy & Treasury Programs Observations Observations 300 arcmin 2 in two fields: HDF-N, CDF-S SIRTF: µm (IRAC+MIPS), 600 hours HST: 4 bands, 500 orbits ACS, near HDF depth Chandra: 2x10 6 sec imaging; XMM: ~5x10 5 sec imaging NorthSouth Science Science Evolution of galaxies, 1 < z < 6 SN Ia detection via scheduling AGN morphologies Potential upgrades: wider fields for AGN, weak-lensing, DEEP fields
1/9/20025 All sky surveys Space advantages: Low B Small over large FOV PSF stability Photometric stability Full sky coverage 24 hr operation Ground advantages Ground advantages Large area telescopes Upgradable detectors (large FOV) High survey speed at BLIP
1/9/20026 Ideal limiting magnitudes Space-survey science: Earth-crossing asteroids (sens.) Earth-crossing asteroids (sens.) Kuiper-belt objects (sens., ) Kuiper-belt objects (sens., ) Transient sources Transient sources Supernovae (e.g. SN Ia) (sens.) Micro-lensing sources (# stars) Dwarf stars: white, brown (sens.) Dwarf stars: white, brown (sens.) Quantify weak lensing in distant galaxies (small , stable PSF) Quantify weak lensing in distant galaxies (small , stable PSF) Parallaxes of faint stars (sens.) Parallaxes of faint stars (sens.) Rare objects (survey to R ~ 27 m ) Rare objects (survey to R ~ 27 m ) Eclipses of exo-planets (photometric stability) Eclipses of exo-planets (photometric stability) High z SN DMT 8.4m
1/9/ t (days) I (mag) z = 1.7 z = 1.4 z = 1.0 SN Ia Detection rate WFPC2: 2 orbit ACS: 2 orbit LSST 4
1/9/20028 SN 1998ff A. Riess, F. Boffi & SNaZ Team ”
1/9/20029 HD b: Exoplanet eclipse 3 hours Ingress EclipseEgress 1σ ~ 2x x10 -4 Kepler selected as Discovery-class Mission courtesy Brown et al. (2001)
1/9/ Has a metallicity (abundance of elements heavier than helium) about one third that of the sun HST/WFPC2 DSS Globular Cluster 47 Tucanae Contains about 10 6 stars, at ~11 Gyr courtesy R. Gilliland et al. (2001)
1/9/ NEO Hazard courtesy DMT consortium
1/9/ Cumulative Distribution of NEAs 300m 4,000 – 77,000 Follow-up problem ? courtesy DMT consortium
1/9/ Planned surveys with spacecraft Galaxy, AGN evolution Galaxy, AGN evolution HST/ACS, NGST Supernovae, Supernovae, HST/ACS+NICMOS, SNAP Eclipsing extra-solar planetary systems Eclipsing extra-solar planetary systems Kepler Astrometric surveys Astrometric surveys Hipparcos, SIM, GAIA ~ /D B ~ Zodiacal light FOV ~ optics limit