Resolution

Selection / Statistics

Depth

Resolution

Depth

Selection / Statistics

WEAVE-LOFAR

LOFAR

WEAVE-

Dutch stations: only these used for large area survey

Core 'superterp'

Core 'superterp'

HBA : 120 - 240 MHz

LBA : 30 - 80 MHz

Core 'superterp'

LBA : 30 - 80 MHz

HBA : 120 - 240 MHz

Tier-1 : will cover whole northern hemisphere

(0.1 mJy RMS at 150 MHz)

Tier-2 :  ~100s of sq.deg to faint flux limits (25 μJy RMS @ 150 MHz)

Tier-3 : ~10s of sq.deg to sensitivities > the deepest existing imaging

(6 μJy @ 150 MHz)

Details: Röttgering et al. 2011

LOFAR Surveys KSP

LOFAR Surveys KSP

Relative to other radio surveys

LOFAR Surveys KSP

In physical terms...

LOFAR Surveys KSP

In physical terms...

Tier 1

Tier 2

Tier 3

Tier 3

Tier 2

Tier 1

LOFAR Surveys KSP

In physical terms...

Tier 1

Tier 2

Tier 3

Tier 3

Tier 2

Tier 1

Good Ionosphere

Bad Ionosphere

Credit: Ger de Bruyn

http://www.astron.nl/dailyimage/index.html?main.php?date=20140307

Credit: Tim Shimwell

Credit: Tim Shimwell

(W. Williams+ 2016)

8 Hrs of observations at 150 MHz 

(now ~60 observed)

~19 sq.deg

RMS ~120-150 uJy/beam

~6" beam

-LOFAR

WEAVE

What is WEAVE?

WHT Enhanced Area Velocity Explorer

• WEAVE is a 960(/940) x 1.3” fibre multi-object spectrograph going on the 4.2m WHT
   
• First light Q1 2019
   
• 2 deg diameter field of view
   
• Complete wavelength coverage from 370–960nm at R=5000 in LR mode

• 20 placeable mini IFUs:
   
  11" x 12" -  1.3" spaxels

IFU mode

• One large IFU:
   
  84" x 97" -  2.6" spaxels

WEAVE Science

• Galaxy Clusters
   
• Galaxy Evolution
  • STEPS
  • WEAVE-APERTIF


• WEAVE-LOFAR
   
• WEAVE-QSO

http://www.ing.iac.es/weave/science.html

• Archaeology
  (Gaia follow-up: radial velocity and abundances)
   
• Stellar, Circumstellar and Interstellar Physics

Galactic

Extra-galactic

-LOFAR

WEAVE

Science goals and survey strategy

PI: Dan Smith, U. of Hertfordshire

“There’s nothing as useless as a radio source”
Jim Condon, 2013

Why not just use photo-z's?

Many LOFAR sources are precisely the populations where photo-z's break down,

e.g. ...

• Extreme emission lines
• presence of RQ-AGN/IR power laws
• lack of strong breaks in photometry

Spectra required to separate SF and RQ-AGN, distinguish accretion modes (high-/low-excitation) etc

and

WEAVE-LOFAR

Survey Design

1. MOS Survey

2. IFU Survey

Spectroscopic follow-up of many LOFAR sources

Resolved spectroscopy of protocluster fields (Ly-alpha/OII emitters around radio AGN)

1. MOS Survey

The MOS surveys have three primary science cases:

• Star-formation evolution across cosmic history
   
• Co-evolution of black-hole and star formation - physics of AGN feedback
   
• Finding radio galaxies in the Epoch of Reionisation at z > 6
   

Simulations indicate that redshift success rates approach 100% at z < 1

1. MOS Survey

WIDE Tier

All sources with S(150) > 10mJy over 10,000 sq.deg

Highlights:

• ~50+ z > 6 radio galaxies for 21 cm absorption experiments
   
• ~250k spectroscopic redshifts and source classifications

Based on SKA Simulated Skies (Wilman et al. 2008, 2010)

1. MOS Survey

MID Tier

 ~250k+ spectra over ~1250 sq.deg
(HETDEX Spring field/H-ATLAS NGP/COSMOS/XMM-LSS)

Highlights:

• Robust constraints on the bright end of SFR function - dust independent SFRs
  
   
• AGN cold and hot accretion modes at z  < 1.3 and z  > 2

Based on SKA Simulated Skies (Wilman et al. 2008, 2010)

1. MOS Survey

DEEP Tier

 ~360k+ spectra over ~70-200 sq.deg
(e.g. Elais N1 / Bootes / Lockman Hole )

Highlights:

• Evolution in the SFR function at low SFRs both at z  < 1.3 and z  > 2
   
• Physics and evolution of the radio-FIR correlation

Based on SKA Simulated Skies (Wilman et al. 2008, 2010)

2. IFU Survey

The LIFU survey aims to study

• the nature of protoclusters
• radio galaxies and their halos
• AGN feedback

The mIFU survey aims to study:    

• AGN in close galaxy pairs
• Weird (interesting) extended sources where optical matching fails

IFU survey aimed at filling poor weather (/bright time) queue

2. IFU Survey

WEAVE-LOFAR IFUs are set-apart by:    

• high resolution of WEAVE
• rare object sensitivity
• large wavelength coverage

IFU survey aimed at filling poor weather (/bright time) queue

Redshift success rates

Redshift success rates

Redshift success rates

Redshift success rates

Redshift success rates