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The other side of galaxy formation: radio line and continuum ‘Great Surveys’ Santa Fe November 2008 Chris Carilli NRAO. ESO. Cosmological deep fields: COSMOS Definitive study of galaxy and SMBG evolution vs. environmnent ACS: 600 orbits for 2deg 2 to I AB = 26 - PowerPoint PPT PresentationTRANSCRIPT
ESO
The other side of galaxy formation: radio line and continuum ‘Great Surveys’
Santa Fe November 2008Chris Carilli
NRAO
Cosmological deep fields: COSMOS
o Definitive study of galaxy and SMBG evolution vs. environmnent
o ACS: 600 orbits for 2deg2 to IAB = 26
o VLA, Spitzer, 11-band SUBARU++, Galex, Chandra/XMM
o Similar to SDSS in volume and resolution but at z > 1
o 2e6 galaxies from z~ 0 to 7
Star formation rate density vs. redshift
‘epoch of galaxy assembly’
Next level of detail: galaxy formation as function of M*
‘specific star formation rates’ = SFR/M*
‘Downsizing’
tH-1
‘active star formation’
‘red and dead’
Zheng+
Star formation history of Universe: dirty little secret
UV correction factor ~ 5x
Optical limitations
Dust obscuration: missing earliest, most active phases of galaxy formation
Only stars and star formation: not (cold) gas => missing the other half of the problem = ‘fuel for galaxy formation’
Radio astronomy: unveiling the cold, obscured universe
Wilson et al.
HST / OVRO CO
mm continuum: thermal emission from warm dust = star formation (see Yun)
(sub)mm lines: molecular gas, fine structure ISM cooling lines
(short) cm lines: low order molecular transitions, dynamics
cm continuum: synchrotron emission = star formation
(long) cm lines: HI 21cm (see Henning)
850um Class 0 protostar
COSMOS VLA deep
16x16x
Full field at 1.4GHz
1.5” resolution
rms ~ 8 uJy/beam
4000 sources (10xHUDF)
(mostly) star forming galaxies
9
10
11
12
13
14
Log
(FI
R L
um
inosi
ty)
ULIRGs~Arp220 SFR ~ 100 Mo/yrLIRGs~ M82 SFR~ 10 Mo/yr
AGN or
Radio Surveys - LimitsRadio Surveys - Limits
Milky Way SFR ~ 1 Mo/yr
40uJy
Submm gals: SFR > 103 Mo yr-1
Pushing uJy radio studies to z>2: Stacking Cosmos BzK, LBG and LAE
Median stacking of high-z ‘dropout’ samples in Cosmos field• 30,000 BzK at z~1.3 to 2.5• 8500 LBGs (U,B,V dropouts) at z~ 3, 4, 5• 100 LAE in NB850 at z = 5.7• ‘normal’ star forming galaxy populations at high redshift• Stacking analysis: ~ sub-uJy limits
4000A
Ly-break
BzK at z=1.7
30,000 sBzK galaxies in Cosmos (>5x previous): Pannella+
star forming
nearIR selected: KAB ~ 23
M* ~ 1010 to 1011 Mo
HST sizes ~ 1” ~ 9kpc
Photo z
z~1.3 to 2.5
Density ~ few x10-4 Mpc-3 ~ 30x SMG
Forming ‘normal’ ellipticals, large spirals?
3.2”
Daddi, McCracken +
HST
2e10 3e11
VLA stack 30,000 sBzK
Pannella +
<S1.4> = 8.8 +/- 0.1 uJy
=> <SFR> ~ 96 Mo yr-1 < 0.1x SMG
Size ~ 1”
SKA (sub-uJy) science before the SKA
S1.4 increases with M* => SFR increases with stellar mass
S1.4 increases with B-z => dust extinction increases with SFR (or M*)
Stacking in bins of 40001010 Mo 3x1011 Mo
Dawn of Downsizing: SFR/M* vs. M*
5x
tH-1 (z=1.8)
z=0.3
1.4GHz SSFR
z=1.5
z=2.1
UV SSFR
SSFR increases with z
SSFR constant with M*, unlike z<1=> ‘pre-downsizing’
z>1.5 sBzK well above the ‘red and dead’ galaxy line
Extinction increases with SFR, M*
<factor 5> UV dust correction needs to be differential wrt SFR, M*
Great Surveys: next gen radio deep fields
Arcsec resolution is required to avoid confusion and detect ‘normal’ star forming galaxies at z > 1.5
All confusion limited (res>5”)
Early Universe Molecular Line Galaxies
Submm galaxies: z ~ 1.5 to 4.5
SDSS J1335+3533 z=6.04
Gas mass (H2)~ 1010 to 1011 Mo (~ 10 to 100x MW)
FIR > 1013 Lo => Star formation rates > 103 Mo yr-1
Giant elliptical galaxy formation at high redshift?
COSMOS J1000+0234 z=4.52
Most distant SMG
QSO host galaxies: z ~ 1 to 6.4
• SMBH ~ 1e9 Mo
• Dust mass ~ 7e8 Mo
• Gas mass ~ 2e10 Mo
• CO size ~ 6 kpc• Dynamical Mass ~ 4e10 Mo
Gas, Dust, Star Form, in host galaxy of J1148+5251 z=6.42
Only direct observations of host galaxy properties
1”
FIR excess -- SED consistent with starburst: SFR ~ 3000 Mo/yr
CO excitation ~ starburst nucleus: Tkin ~ 100K, nH2 ~ 1e5 cm-3
Radio-FIR correlation
50KElvis QSO SED
Continuum SED and CO excitation: ISM physics at z=6.42
NGC253
MW
Building giant elliptical galaxies + SMBHs at tuniv < 1Gyr
z=6 QSO host stats (33 total)
10.5
8.1
6.5
Li, Hernquist, Roberston..
z=10
10 in dust: FIR > 1e13 Lo
5 in CO: Mgas > 1e10 Mo
10 at 1.4 GHz continuum
2 in [CII]
=> SFR > 103 Mo yr-1
• Rapid enrichment of metals, dust, molecules
• Rare, extreme mass objects: ~ 100 SDSS z~6 QSOs on entire sky
LFIR vs L’(CO) ~ SFR vs. total gas mass
Integrated Schmidt-Kennicutt Law
High-z sources = 10 -- 100 x Mgas of Milky WayIndex=1.5
Low z
tdep~3e8 yr
Current sens ~ few x1010 Mo
1e3 Mo/yr
High z
tdep~1e7 yr
• Star formation efficiency = SFR per unit gas mass, increases with increasing SFR
• Gas depletion timescale = Mgas/SFR decreases with SFR
SFR
Gas Mass
sBzK: not extreme starbursts, but massive gas reservoirs
6 of 6 sBzK detected in CO with Bure
Gas mass > 1010 Mo ~ submm galaxies, but
SFR < 10% submm gal
5 arcmin-2 (~50x submm galaxies)
Daddi + 2008
Excitation = Milky Way (not starburst)
FIR/L’CO = spiral (not starburst)
Extreme gas rich galaxies without extreme starbursts
Gas depletion timescales > 5 x108 yrs
Starburst
Dannerbauer + Daddi +
sBzK
Low z ellipt
??
Current limitation: CO search requires optical pre-selection
Mgas >~ M*
Great Surveys: blind molecular line ‘piggy back’ surveys using 8GHz bandwidth
EVLA: CO 1-0 at z = 1.4 to 1.9 (48 to 40 GHz)
FoV ~ 1 arcmin2 => ~ 2 or 3 sBzK (M* > 1010 Mo)
rms (10hr, 300 km/s) = 50 uJy => L’(CO) = 1.9e9 K km/s pc2
4 mass limit: M(H2) = 3x1010 Mo (Galactic X factor)
=> Every ‘Q-band’ full synthesis will have ~ 1 sBzK CO detection
ALMA: CO 2-1 at z = 1.45 to 1.7 (93 to 85 GHz)
FoV ~ 1 arcmin2 , but fractional BW (z) ~ 1/2 EVLA
S2-1 ~ 4xS1-0 (in Jy) and rms (300 km/s) ~ 30uJy
Mass limit ~ 5x109 Mo
=> Every ‘Band 3’ full synthesis will have ~ 3 sBzK CO detections
What is EVLA? First steps to the SKABy building on the existing infrastructure, multiply ten-fold the VLA’s observational capabilities, including 10x continuum sensitivity (1uJy), full frequency coverage (1 to 50 GHz), 80x BW (8GHz)
• Antenna retrofits now 50% completed.• Early science Q1 2010, using new correlator. • Full receiver complement completed 2012.
AOS Technical Building
Array operations center
What is ALMA?International collaboration to build & operate largest millimeter/submm array at 5000m in northern Chile -> order of magnitude, or more, improvement in all areas of (sub)mm astronomy, including resolution, sensitivity, and frequency coverage.
Antenna commissioning in progress
•Antennas, receivers, correlator in production: best (sub)mm receivers and antennas ever!•Site construction well under way: Observation Support Facility, Array Operations Site, antenna pads•North American ALMA Science Center (C’Ville): support early science Q4 2010, full ops Q4 2012
ESO
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