The Transient Radio Sky Astrophysical and Artificial

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Evolution of radio telescopes (Braun 1996)
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SKA in context
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Fields of View
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Centimeter observations of thermal sources at mas
resolution
X PP-disks
X NGC1068 Disk
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• 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. 2004.
• 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 (www.skatelescope.org/ska_
  science.shtml)
• 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 (www.skatelescope.org/ska_memos.shtml)

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SKA Designs ("compliance" matrix) http//www-astro
.physics.ox.ac.uk/sr/ska/ska_matrix.html
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? UPGRADE? YES YES YES UPGRADE? UPGRADE?
1 Galactic NTB YES UPGRADE? NO YES UPGRADE? YES YES UPGRADE?
2 Transients UPGRADE? NO NO NO NO NO NO NO
2 Pulsars UPGRADE? NO NO NO NO NO NO NO
2 SETI UPGRADE? NO NO NO NO NO NO NO
3 EOR UPGRADE? NO UPGRADE? UPGRADE? UPGRADE? UPGRADE? UPGRADE? UPGRADE?
4 HI surveys / LSS YES UPGRADE? UPGRADE? YES YES YES YES YES
4 Continuum surveys UPGRADE? NO NO UPGRADE? UPGRADE? UPGRADE? UPGRADE? UPGRADE?
4 CO surveys YES NO NO UPGRADE? NO UPGRADE? YES YES
5 Hi-z AGN UPGRADE? NO NO YES UPGRADE? YES YES UPGRADE?
5 Inner AGN UPGRADE? NO NO UPGRADE? NO UPGRADE? YES UPGRADE?
6 Protoplanetary systems UPGRADE? NO NO UPGRADE? NO UPGRADE? YES YES
7 CMEs UPGRADE? NO UPGRADE? UPGRADE? YES YES UPGRADE? YES
7 SS bodies YES NO NO UPGRADE? NO UPGRADE? UPGRADE? YES
8 IGM non thermal YES UPGRADE? NO YES YES YES UPGRADE? UPGRADE?
8 IGM thermal UPGRADE? NO NO UPGRADE? NO NO YES UPGRADE?
9 Spacecraft Tracking UPGRADE? NO NO UPGRADE? NO NO YES UPGRADE?
9 Geodesy UPGRADE? NO NO UPGRADE? NO UPGRADE? UPGRADE? UPGRADE?
Notes Level-1 science may still be missing.
'Level-1' probably not a uniform measure across
the WGs. Last updated 10th August 2002
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Highest z HI emission to date 110 hours VLA
GMRT
Verheijen, Dwarakanath, van Gorkom
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Maximum redshift for a 360 hour integration with
SKA
2000 galaxies/ deg
M 101
100 000
Star formation with z
30 000
M 51
SMC
Crucial epoch
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z 4
z 2
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Braun 1996
M101 z 0.2
Imaging to z1 gt TF distances gt peculiar motions
z 0.45
z 0.9
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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 gt evolution of bias
parameter
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SKA continuum survey HDFx10000
Hopkins 1999
5e8 sources at gt 0.3 uJy over 1000 sq.deg. Star
formation history of the universe unbiased by
dust Massive black hole formation and accretion
history
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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?
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Maximum redshift for a 360 hour integration with
SKA
resolved flux (0.1) total flux (1)
M 51
resolved flux total flux
NGC 6946
Thermal flux
M 33
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HI 21cm absorption in deep, wide surveys
1229-021 Briggs 1996 z_abs 0.4
N(Sgt1mJy) 36000 gt 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
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OH megamasers in deep HI surveys beacons to high
z, merging starburst galaxies
Briggs 1995
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Highest z CO emission to date 24 hrs/source w.
VLA M(H_2) few e11 M_sun
1202-0725 z 4.69 CO(2-1)
1331-0417 z 4.41 CO(2-1)
08275255 z 3.91 CO(1-0)
23221944 z 4.12 CO(2-1)
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08275255 at z3.9 An Einstein Arc in CO
CO(2-1)
8 GHz
300 pc
HST
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SKA and CO
M(H_2) few e9 M_sun
22 GHz
43 GHz
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Optimal CO surveys speed of discovery
Carilli and Blain 2002
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HCN (89 GHz) Dense gas starburst tracer?
Solomon 2001
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Conflict I low vs. high frequency?
HI Surveys require frequencies lt 1.4 GHz CO
Surveys require frequencies gt 20 GHz Can we do
both with one design?
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Epoch of Reionization
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Evolution of the neutral IGM (Gnedin) Cosmic
Phase transition
HI fraction
Ionizing intensity
density
Gas Temp
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Gunn-Peterson effect
Barkana and Loeb 2001
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Discovery of the EOR? (Becker et al. 2002)
Fast reionization at z 6.3 gt opaque at l_obs
lt 1 mm
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Lower limit to z_reio GP Effect
Fan et al. 2002
F(HI) gt 0.01 at z 6.3
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Upper limit to z_reio CMB anisotropies
Briggs
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Studying the IGM beyond the EOR HI 21cm
observations with the Square Kilometer Array and
LOFAR
t_21cm 1e-8 t_Lya
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Temperatures Spin, CMB, Kinetic and the 21cm
signal
Tozzi 2002
T_CMB
T_s
T_K

• Initially T_S T_CMB
• T_S couples to T_K via Lya scattering
• T_K 0.026 (1z)2 (wo. heating)
• T_CMB 2.73 (1z)

• T_S T_CMB gt no signal
• T_S T_K lt T_CMB gt Absorption against CMB
• T_S gt T_CMB gt Emission

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HI 21cm Emission
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Difficulty with (LSS) emission observations
confusion by foreground radio sources (di Matteo
2001)
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Cosmic Web after reionization Ly alpha forest
(d lt 10)
142223 z3.62 Womble 1996
N(HI) 1e13 -- 1e15 cm-2, f(HI/HII) 1e-5 --
1e-6 gt Before reionization N(HI) 1e18 1e21
cm-2
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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)

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SKA observations of absorption before the EOR A/T
2000 m2/K 240 hrs 1 kHz/channel
z 10
z 8
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Radio sources beyond the EOR?

0924-220 z 5.19 S_151 600 mJy
09135821 z 5.12 S_151 150 mJy
1
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Inverse Compton losses off the CMB
U_B (radio lobe)
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Radio sources beyond the EOR sifting problem
(1/1400 per 20 sq.deg.)
USS samples (de Breuck et al.)
1.4e5 at z gt 6
2240 at z gt 6
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Conflict II Long vs. Short baselines?
EOR emission requires arcmin resolution gt
baselines lt 5km EOR absorption requires arcsec
resolution gt baselines gt 300km Both are
sensitivity limited where to put our collecting
area?