What are the Big Questions and how can Radio Telescopes help answer them? Roger Blandford KIPAC Stanford

What are the Big Questions and how can Radio Telescopes help answer them? Roger Blandford KIPAC Stanford

Radio Astronomy in 1957 ~100 MHz ~100 Jy ~100 sources ~100 arcseconds 2

Radio Astronomy in 2007 ~ 10 MHz - ~ 1 THz ~ 10 μjy ~ >10 6 sources ~ 100 μas 3

Radio Astronomy in 2057? ~ 1 MHz - ~ 1 THz ~ 1 pjy ~ 10 12 sources ~ 100 pas 4

Radio Telescopes in 2057 ALMA, EVLA + SKA++ All digital phased array International network of telescopes Linked by optical fibers with ample bandwidth Low T amplifiers Distributed computing will keep up Orbiting antennae Up to AU baselines Cheap large (inflatable?) antennas Radio active and adaptive optics Low frequency lunar array? 5

Organization Physical Cosmology Cosmography, DE, DM, growth of structure Cosmography IGM, Galaxy formation Astrophysics GR, BH, NS, AGN Astronomy Local galaxies, star formation, SNR Life in the Universe Astrochemistry, astrobiology, SETI 6

Physical Cosmology 7

Cosmology Distances VLBA parallax FΛCDM a(t) ~ sinh 2/3 t, w= -1; j=a a 2 /a 3 =1 Scale invariant fluctuations CMB Measure d(a), φ(a) BAO, SZ, WL, SKA-lo 8

Inflation Topological defects Phase transitions CMB Lens pairs MSP timing arrays Serendipity 9

Recombination Measured to limit from irreducible foregrounds~10nk? Accomplishments Fundamental cosmological parameters - To ~0.01 - Recombination lines Density fluctuation spectrum to l~10 4 - Initial conditions Tensor modes - Inflation? Non-Gaussianity - Strings monopoles, etc - Lens searches Monitor growth of structure - SZ, ISW, lensing 10

Growth of Structure Statistics phenomenal SZ surveys from South Pole Good working model except Dwarf dearth Cluster entropies Nonlinear phase Galaxy surveys most likely to contribute to understanding of galaxy formation and evolution 11

Cosmoserendipity Gravitational radiation background Neutrino masses CMB, LSS anomalies Physics of DE, DM Golden gravitational lenses Rare high order catastrophes Probes of structure as well as sources 12

Dark Ages H-line Standard model has linear growth of structure Standard physics, sanity check Explore the frequency dimension Recombination lines Epoch of reionization When? 21(1+z reion )cm, 7<z reion <20 Crucial for telescope design Intergalactic meteorology? Connect to first stars, galaxies 13

Galaxy Formation and Evolution Re-ionization happens fast through massive stars followed by AGN? Empirical history of assembly of galaxy Multiwavelength enterprise - ALMA, SKA++ - + JWST, Con-XEUS, GSMT CO in hi z quasar hosts 14

Surveys and Monitoring Whole sky surveyed and monitored to limiting flux, that Ω(S,,t), N(S,,t) SKA FOV ~ 0.01 of sky at low frequency Confusion limit at low frequency High connectivity to multi-wavelength surveys GLAST whole sky in 3hr LSST in 3d Billions of sources in 3D EVLA x 0.1 SKA++ x 0.001 15

Astrophysics Relativity Radio astronomy has contributed almost all the best quantitative measurements in GR Much more to come Neutron stars are nuclear/many body physics laboratories Dynamical and thermal Relativistic outflows Novel QED, plasma physics 16

Relativity and Compact Stars Thousands of MSP, binary pulsars Improved timing De-dispersion Tests of weak field gravity Spin orbit effects M[R] Black hole NS systems Eclipsing Remote no hair tests Ter 5 17

NS/BH Spacetimes Direct resolution at mm wavelengths Sgr A* M87 Limited by S, λ, b Pulsar timing tests Double pulsar PK 1 PK 3 PK 2 18

Angular limit Terrestrial telescopes connected with optical fibers Angular limit θ>[10 (b/r E ) -1 ν 9-1, 0.5 ν 9-2.2 ]mas, high latitude θ>ν 9-2 as, Galactic Center Baseline limit b< [10 10 ν 9 1.2, 3x10 14 D 9 1/2 ν 9-1/2 ] cm Linear resolution limit R>3x10 14 D 9 1/2 ν 9-1/2 cm M 9 >D 9 1/2 ν 9-1 19

Engineering of Relativistic Jets Disk + spinning black hole + magnetic field => Jet How? High dynamic range mapping of Galactic and extragalactic jets Radio polarization Multi-lambda campaigns Numerical simulations Disk-jet connection Accretion disks 20

Astroserendipity LIGO, LISA Locate incipient mergers - LSST, SKA++ Cosmic explosions GRBs, magnetars Flare stars Neutrino bursts VHE neutrino detection UHECR radio detection GW signals 21

Astronomy Study of Galactic structure Molecular clouds as cradles of star formation Galactic ecocycles Stellar evolution 22

ALMA Spectroscopy 23

Life in the Universe Terrestrial planets exist! Astrobiology and chemistry Prebiotic molecules - entire spectrum ALMA debris disks, gaps, bloated planets Search for habitable planets Habitability of nearby planets Stellar flares SETI program Checkered history ATA Dedication Ultimately has strong popular support Parasitic searches for patterned noise/signals - Great leaps in electronics signal/information processing 24