# Presentation: 879451

## The other side of galaxy formation: radio line and continuum ‘Great Surveys’

- ESO

- Santa Fe November 2008
- Chris Carilli
- NRAO

## Cosmological deep fields:  COSMOS

**Cosmological deep fields:  COSMOS**
** ****Definitive study of galaxy and SMBG evolution vs. environmnent**
** ****ACS: 600 orbits for 2deg****2**** to I****AB**** = 26**
** ****VLA, Spitzer, 11-band SUBARU++, Galex, Chandra/XMM**

** ****Similar to SDSS in volume and resolution but at z > 1**
** ****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*

**Next level of detail: galaxy formation as function of M*******
**‘****specific star formation rates’ = SFR/M*******

**‘****Downsizing’**

**t****H****-1**

**‘****active star formation’**

**‘****red and dead’**

**Zheng+**

## Star formation history of Universe: dirty little secret

**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

**COSMOS VLA deep**

**Full field at 1.4GHz**
**1.5” resolution **
**rms ~ 8 uJy/beam**
**4000 sources (10xHUDF)**

**(mostly) star forming galaxies**

## Radio Surveys  -  Limits

- 9

- 10

- 11

- 12

- 13

- 14

- Log (FIR Luminosity)

- ULIRGs~Arp220 SFR ~ 100 Mo/yr

- LIRGs~ M82 SFR~ 10 Mo/yr

- AGN or

**Radio Surveys  -  Limits**

- Milky Way
- SFR ~ 1 Mo/yr

- 40uJy

**Submm gals: SFR > 10****3**** M****o**** 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

## 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**

## VLA stack 30,000 sBzK

- 3e11

**VLA stack 30,000 sBzK**
**Pannella + **

**<S****1.4****> = 8.8 +/- 0.1 uJy**
**=> <SFR> ~ 96 M****o**** yr****-1 ****< 0.1x SMG**
**Size ~ 1”**

**SKA (sub-uJy) science before the SKA**

## S1.4 increases with M* => SFR increases with stellar mass

**S****1.4**** increases with M***** ****=> SFR increases with stellar mass**

**S****1.4**** increases with B-z => dust extinction increases with SFR (or M*********)**

**Stacking in bins of 4000**

**10****10**** M****o**

**3x10****11**** M****o**

## Dawn of Downsizing: SFR/M*  vs. M*

**Dawn of Downsizing: SFR/M*****  ****vs. M*******

-  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

**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 (H****2****)~ 10****10**** to 10****11**** M****o****  ****(~ 10 to 100x MW)**
** ****FIR > 10****13**** L****o**** => Star formation rates > 10****3**** M****o**** yr****-1 **
** ****Giant elliptical galaxy formation at high redshift?**

**QSO host galaxies: z ~ 1 to 6.4**

## Gas, Dust, Star Form, in host galaxy of J1148+5251 z=6.42

-  SMBH ~ 1e9 Mo
-  Dust mass ~ 7e8 Mo
-  Gas mass ~ 2e10 Mo
-  CO size ~ 6 kpc
-  Dynamical Mass ~ 4e10 Mo

- Only direct observations of host galaxy properties

**1”**

## Continuum SED and CO excitation: ISM physics at z=6.42

-  CO excitation ~ starburst nucleus: Tkin ~ 100K, nH2 ~ 1e5 cm-3

- Radio-FIR correlation

- 50K

- Elvis QSO SED

- NGC253

- MW

## Building giant elliptical galaxies + SMBHs at tuniv < 1Gyr 

- 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 Way

**Index=1.5**

**Low z**
**t****dep****~3e8 yr**

**Current sens ~ few x10****10**** M****o**

**1e3 M****o****/yr**

**High z**
**t****dep****~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 > 10****10**** M****o**** ~ 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

**sBzK**

**Low z ellipt**

**??**

**Current limitation: CO search requires optical pre-selection **

**M****gas**** >~  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 SKA

- By 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

## END

- ESO