180 likes | 259 Views
General Astrophysics with TPF-C. David Spergel Princeton. Please, Chas…. Ability to point at alternative targets Wide (but not ultra-wide field imaging) 5’ x 5’ Astrometry well-sampled pixels Variable Objects (SN) large area/near-IR
E N D
General Astrophysicswith TPF-C David Spergel Princeton
Please, Chas…. • Ability to point at alternative targets • Wide (but not ultra-wide field imaging) • 5’ x 5’ • Astrometry well-sampled pixels • Variable Objects (SN) large area/near-IR • Ability to observe in parallel mode while doing planet finding (control of scattered light) • GRISM capability?
Division of Focal Plane Planet finding GENERAL ASTROPHYSICS
UNIQUE CAPABILITY Coronagraphy Polarimetry High resolution/wide field (10 mas/5’) IFU + high spatial resolution Stable PSF Astrometry Photometry OTHER INSTRUMENTS JWST SIM GAIA Ground-based 20/30-m LSST Many 8-m class telescopes Discovery Space
Astrometric Capabilities • Able to get 30-100 mas astrometry for faint objects • Tie to SIM references • Distance to faint galactic objects • Proper motions for main sequence stars in Baade’s window and in tidal tails
Key Science Questions • What is the dark energy? • What is the dark matter? • How do black holes form? What feeds them? How do they affect their environment? • How do galaxies form and evolve? • How do stars and planetary systems form and evolve? • Explore diversity of worlds that might harbor life
What is the dark energy? • Measure angular diameter distance • Supernova as standard candles Search for supernova in parallel observing mode (and other variable objects) TPF-C has ~8 x collecting area of SNAP • Growth rate of structure • Strong lensing (Survey rich cluster arcs to measure their mass). Much higher arc density that ACS+HST [see Dedeo’s talk] • Weak lensing of galaxies observed in parallel mode (50-100 pencil beams)
Parallel Extreme Deep Fields • 50 target stars (50% of time [5 yr mission]) • 18 days of integration per field with 6 x HST collecting area > UDF sensitivity on 50 fields • Multiple visits: variability studies • Very complementary to LSST program • Complement with repeat return visits? • 200 comparative planetology targets (25% of mission time) • 3 days of integration ~ HDF sensitivity
Comparison with HST Supernova search • HST study • Riess et al. 2004 • 5 epochs at intervals of 45 days (0.1 square degrees) in Z band (2000 s exposures) • Limiting mag of 26 • Parallel fields • 10x area (50 5’ x5’ field) • Longer time-baseline • Out to 1.7 micron, SNIa to z~3 (SNII to higher z) • ~100 x HST Supernova sample Riess et al. 2004
What is the dark matter? • Measure clustering properties of dark matter • In our own Galaxy: Tidal tails--- extend SIM tidal tail program by obtaining proper motions for stars in tidal streams (requirement: 10 km/s at 20 kpc -> 100 mas) • In clusters of galaxies: strong lensing
Strong Lensing: Detailed Studies of Arcs • Resolve substructure in arcs • Detect many more arcs • Use surface brightness constraints to limit lens models • Use features in arcs to constrain lumpiness in cluster halos q= 0.01 (M/106 Msun)1/2 See Dedeo’s talk
How Are Galaxies Assembled? • Galaxies far away • Extreme deep field imaging (complemented by JWST imaging of same fields and spectroscopy with the 20/30-meters) • Galaxies nearby • Stellar population studies in M31 • White dwarf sequences in GCs [M4 study can be extended further out and combined with SIM distances] • Orbits for stars down to main sequence in Baade’s window [SIM astrometry + multi-epoch imaging] (e.g., Kuijken & Rich’s HST program)
Black Holes and Their Environments • Extend studies of black hole properties in nearby galaxies (IFU with higher resolution?) • Coronagraphic Imaging of Host Galaxies • Image M31 nucleus • Resolve nature of double nucleus • Follow orbits around black hole • Probe black holes near “hang-up radius” (Yu 2002) • Imaging or astrometry
Imaging of fine details of low surface brightness host/lens galaxies of gravitationally lensed quasars The details of low surface brightness resolved objects are often key to constraining lens models but nearly superimposed bright quasar images make their detection difficult. Host galaxy of a bright & low redshift quasar. ----> Change with redshift? <---- Optical Einstein Ring gravitational lens. Reconstructed 0.01” resolution image of a high z star formation burst galaxy. ----> E. Turner 4/14/04 TPF Ancillary Science
Requirements • Pointing without bright target star • Parallel mode operation (data download + scattered starlight) • Wide field imaging capability (5’x5’)? • Small pixels on some of field for better astrometric capability • Spectroscopy? GRISM