1. Evolution of radio telescopes (Braun 1996)

2. SKA in context

3. Fields of View

4. Centimeter observations of thermal sources at mas resolution
X PP-disks
X NGC1068 Disk

7. Current documentation:
ISAC Mandates:
Revise science case and requirements, involving larger community, and put in context of future capabilities at other wavelengths. Goal: new Taylor-Braun document by Aug
Evaluate (w. EMT) proposed SKA designs and advise ISSC. Goal: final design and site choice by ISSC in 2007
Current documentation:
Science with the Square Kilometer Array, R. Taylor & R. Braun, 1999 (
Perspectives on Radio Astronomy: Science with Large Antenna Arrays, ed. M. van Haarlem, 1999 (ASTRON)
SKA memo series: Groningen (2002), Bologna (2002), and Berkeley(2001), science working group reports (

8. Compliance Matrix: www-astro.physics.ox.ac.uk/~sr/ska/ska_matrix.html
SKA Designs ("compliance" matrix)
Compliance Matrix: www-astro.physics.ox.ac.uk/~sr/ska/ska_matrix.html
Level 1 Science
Strawman 
China 
Europe 
India 
Ozlens 
Ozcyli 
USA 
Canada 
1: Galactic HI
YES
UPGRADE?
1: Galactic NT+B NO
2: Transients
2: Pulsars
2: SETI
3: EOR
4: HI surveys / LSS
4: Continuum surveys
4: CO surveys
5: Hi-z AGN
5: Inner AGN
6: Protoplanetary systems
7: CMEs
7: SS bodies
8: IGM non thermal
8: IGM thermal
9: Spacecraft Tracking
9: Geodesy
Notes: Level-1 science may still be missing. 'Level-1' probably not a uniform measure across the WGs. Last updated: 10th August 2002

9. Highest z HI emission to date: 110 hours VLA + GMRT
Verheijen, Dwarakanath, van Gorkom

10. M 101 M 51 SMC Maximum redshift for a 360 hour integration with SKA
2000 galaxies/ deg
M 101
Star formation with z
30 000
M 51
Out to where do we detect what mass galaxies in a 360 hour deep field HI survey. Slide illustrates mass ranges of dwarf, normal (L*) and giant galaxies.
SMC
Crucial epoch

11. z = 4
z = 2

12. Imaging to z=1 => TF distances => peculiar motions
Braun 1996
M101 z = 0.2
Imaging to z=1 => TF distances => peculiar motions
z = 0.45
z = 0.9

13. SKA HI Survey: ‘Sloan x 100’
1000 hrs, 1000 sq.deg.
Evolution of gas and dark matter content of galaxies
Origin of Hubble sequence and density-morphology relation
Evolution of LSS and cluster velocity dispersions
Tully-Fisher distances: Peculiar motions => evolution of bias parameter

14. SKA continuum survey: HDFx10000
Hopkins 1999
5e8 sources at > 0.3 uJy over 1000 sq.deg.
Star formation history of the universe unbiased by dust
Massive black hole formation and accretion history

15. Dust obscured star formation at high z:
The brightest mm source in HDF not detected by HST!
Elliptical galaxy formation in dusty, high z starbursts?

16. Maximum redshift for a 360 hour integration with SKA
resolved flux (0.1”) total flux (1”)
M 51
resolved flux total flux
NGC 6946
Continuum of normal galaxies: to what redshifts de we detect normal galaxies in a 360 hour integration and a 500 MHz bandwidth piggy-back survey with the HI deep fields
Thermal flux
M 33

17. HI 21cm absorption in deep, wide surveys
Briggs 1996
z_abs = 0.4
N(S>1mJy) = => O(50000) HI 21cm absorption lines by damped
Ly alpha systems (1e20 /cm/cm, T_spin = 1000 K)
Dense ISM in nascent galaxies
Dust unbiased QSO statistics: ‘Red quasars’ and ‘dark’ gravitational lenses
Evolution of physical constants

18. OH megamasers in deep HI surveys: beacons to high z, merging starburst galaxies
Briggs 1995

19. Highest z CO emission to date: 24 hrs/source w
Highest z CO emission to date: 24 hrs/source w. VLA M(H_2) = few e11 M_sun
z =4.69
CO(2-1)
z = 4.41
CO(2-1)
z = 3.91
CO(1-0)
z = 4.12
CO(2-1)

20. 0827+5255 at z=3.9: An ‘Einstein Arc’ in CO
8 GHz
300 pc
HST

21. SKA and CO
M(H_2) = few e9 M_sun
22 GHz
43 GHz

22. Optimal CO surveys: ‘speed of discovery’
Carilli and Blain 2002

23. HCN (89 GHz): Dense gas + starburst tracer?
Solomon 2001

24. Conflict I: low vs. high frequency?
HI Surveys require frequencies < 1.4 GHz
CO Surveys require frequencies > 20 GHz
Can we do both with one design?

25. Epoch of Reionization:

26. Evolution of the neutral IGM (Gnedin): ‘Cosmic Phase transition’
HI fraction
Ionizing intensity
density
Gas Temp

27. Gunn-Peterson effect
Barkana and Loeb 2001

28. Fast reionization at z = 6.3 => opaque at l_obs < 1 mm
Discovery of the EOR? (Becker et al. 2002)
Fast reionization at z = 6.3 => opaque at l_obs < 1 mm

29. Lower limit to z_reio: GP Effect
Fan et al. 2002
F(HI) > 0.01 at z = 6.3

30. Upper limit to z_reio: CMB anisotropies
Briggs

31. Studying the IGM beyond the EOR: HI 21cm observations with the Square Kilometer Array and LOFAR
t_21cm = 1e-8 t_Lya

32. Temperatures: Spin, CMB, Kinetic and the 21cm signal
Tozzi 2002
T_s
T_CMB
T_K
Initially T_S= T_CMB
T_S couples to T_K via Lya scattering
T_K = (1+z)^2 (wo. heating)
T_CMB = (1+z)
T_S = T_CMB => no signal
T_S = T_K < T_CMB => Absorption against CMB
T_S > T_CMB => Emission

33. HI 21cm Emission

34. Difficulty with (LSS) emission observations: confusion by foreground radio sources (di Matteo 2001)

35. Cosmic Web after reionization = Ly alpha forest (d <= 10)
z=3.62 Womble 1996
N(HI) = 1e e15 cm^-2, f(HI/HII) = 1e e-6
=> Before reionization N(HI) =1e18 – 1e21 cm^-2

36. Cosmic Web before reionization: HI 21cm Forest
Carilli, Gnedin, Owen 2002
Mean optical depth (z = 10) = 1% = ‘Radio Gunn-Peterson effect’
Narrow lines (1 to 10%, few km/s) = HI 21cm forest (d = 10)

37. SKA observations of absorption before the EOR
A/T = 2000 m^2/K hrs 1 kHz/channel
z = 10
z = 8

38. Radio sources beyond the EOR?
z = 5.19 S_151 = 600 mJy
z = 5.12 S_151 = 150 mJy 1”

39. Inverse Compton losses off the CMB
= U_B (radio lobe)

40. Radio sources beyond the EOR:
sifting problem (1/1400 per 20 sq.deg.)
USS samples (de Breuck et al.)
1.4e5 at z > 6
2240 at z > 6

41. Conflict II: Long vs. Short baselines?
EOR emission requires arcmin resolution => baselines < 5km
EOR absorption requires arcsec resolution => baselines > 300km
Both are sensitivity limited: where to put our collecting area?